Taxonomy a

)

1

1 Berliner geowiss. Abh. E 16

1 Gundolf-ERNST-Festschrift

607-643

Berlin 1995

Taxonomy and Evolution of Late Famennlan Tornocerataceae (Ammonoldea)

R. Thomas BECKER BECKER, R.T. (1995): Taxonomy and Evolution of Late Famennian Tornocerataceae (Ammonoidea).­ Berliner geowiss. Abh. (E) 16: 607-643, Berlin. Abstract: Rich collections from the late Famennian (UD IV to VI) of the Ma'ider (Southern Morocco) yielded a range of new, rare and widely distributed but poorly known Tornocerataceae. New taxa are: Planitornoceras pugnax n.gen. n.sp, Gundolficeras n.gen. (type-species: Lobotornoceras bicaniculatum PETIER), Exotornoceras fezzouense n.sp., ?Exot. sylviae n.sp., and Posttornoceras sodalis n.sp. Other taxa are revised in detail. Discoclymenia shows typical tornoceratid early stages with slight falcate ribbing and ventrolateral furrows. The Posttornoceratidae are re-assigned to the Tornocerataceae and embrace all forms with tripartite lateral lobe. Posttornoceras and Alpinites are recorded for the first time from the Ma'ider. The spatial and stratigraphical distribution of Famennian Tornocerataceae is reviewed. The evolution of active pelagic (Falcitornoceratini and Posttornoceratidae) and mega-planktonic (Aulatornoceratini) lineages was influenced in different ways by eustatic changes and global extinction events. Certain bradytelic groups evolved slowly in deeper-water, often hypoxic environments and, sometimes after extended Lazarus Phases, spread with transgression to become an accessory part of assemblages in shallower shelf areas. Major and rapid regressions drastically reduced the global ecospace of most Tornocerataceae and caused extinctions. Zusammenfassung: Reichhaltige Aufsammlungen aus dem höheren Famennium (UD IV-VI) des Ma'ider (S-Marokko) enthalten eine Reihe von neuen, seltenen oder trotz weiter Verbreitung noch ungenügend bekannten Tornocerataceae. Neu eingeführte Formen sind: Planitornoceras pugnax n.gen. n.sp., Gundolficeras n.gen (Typus-Art: Lobotornoceras bicanicu/atum PETIER), Exotornoceras fezzouense n.sp., ? Exot. sylviae n.sp. und Posttornoceras sodalis n.sp. Andere Arten werden detailliert revidiert. Discoclymenia besitzt typisch tornoceratide Frühstadien mit Sichelberippung und ventrolateralen Längsfurchen. Die Posttornoceratidae werden endgültig zu den Tornocerataceae gestellt und umfassen alle Formen mit dreigeteiltem Laterallobus. Posttornoceras und Alpinites werden erstmalig im Ma'ider nachgewiesen. Die räumliche und zeitliche Verbreitung der Tornocerataceae des Famenniums wird ausführlich zusammengestellt. Die Evolution von Gruppen mit unterschiedlich aktiv-pelagischer (Falcitornoceratini und Posttornoceratidae) und mega-planktonischer (Aulatornoceratini) Gehäuse­ Anpassung waren stark von eustatischen Schwankungen und globalen Aussterbe-Ereignissen betroffen. Einige bradytelische Gruppen entwickelten sich langsam in oft Sauerstoff-armen Tiefwasser-Gebieten und breiteten sich, z.T. nach langen gl9balen Nachweislücken (Lazarus-Phasen), episodisch und als untergeordnetes Faunenelement im Zuge von· Transgressionen aus. Kräftige und schnelle Regressionen reduzierten drastisch den Lebensraum der Tornocerataceae und führten zu Aussterben. Key Words: Upper Devonian, Ammonoidea, taxonomy, phylogeny, paleoecology, biostratigraphy. Address of the author: Institut für Paläontologie, Freie Universität Berlin, Malteserstr. 74-100, Haus D, 12249 Berlin, Germany. 1. lntroduction In terms of survlval, the Tornocerataceae were the most successful of all Devonian goniatite superfamilies and ranged from the late Eifelian (BECKER & HOUSE, 1994) almost to the Devonian-Carboniferous boundary. Among contemporaneous ammonoids, only the low­ divers bactritids had a longer timespan. Tornoceratids managed to survive severe global extinctions such as the Kacak, Taghanic, Kellwasser and Condroz Events (HOUSE, 1985, 1993) although specific lineages within the group were badly atfected (e.g., BECKER, 1993a, b).

The phylogeny of the Tornoceratidae has been used as an outstanding example to illustrate the fossil record of evolution (HOUSE, 1963) but at that time little data on late representatives (Famennian IV to VI) of the group were available. HOUSE (1965) used detailed morphological analyses of North American tornoceratid successions for taxonomy and biostratigraphy in an early study of heterochrony in the group. Upper Devonian tornoceratid phylogeny was reviewed by HOUSE & PRICE (1985) but, again, the systematic position of the few known late members of the family remained ambiguous.

608

BECKER,

Genera with biconvex growth lines but with more complex sutures such as Posttornoceras and Discoclymenia were variously linked with typical tornoceratids or with sporadoceratids {SCHINDE­ WOLF, 1923; PETIER, 1959; BOGOSLOVSKIY, 1971; PETERSEN, 1975; HOUSE, 1981; BECKER, 1993a, b). Generally, there is a surprisingly poor state of knowledge of even widely quoted goniatite taxa such as Disco. cucul/ata v.BUCH. This underlines the necessity of detailed revisions. The Devonian of the northwestern Gondwana epicratonic shelf {especially southern Algeria and southern Morocco) has been celebrated for its widely spread and faunally diverse outcrops in ammonoid biofacies {e.g., ROCH, 1950; PETIER, 1959; BECKER, 1993b). So far, only few localities have been the subject of detailed taxonomic and biostratigraphical analyses {BENSAID, 1974; GÖDDERTZ, 1987; BECKER, 1993b; BECKER & HOUSE, 1994). Apart from general reviews (TERMIER, 1936; ROCH, 1950; CHOUBERT, 1952), no detailed description of any late Famennian fauna and locality of southern Morocco has ever been published. Aich new collections from the Marder by the author üointly with Prof. M.R. HOUSE) and material kindly made available by Dr. V. EBBIGHAUSEN (Odenthal) include a range of rare, new and insufficiently studied Tornocerataceae which will be described herein and which, together with unpublished collections from various other parts of the globe, allow insights into the systematics, distribution and Famennian evolution of the superfamily. 2. Localltles and material The sedimentology of the Famennian of the Tafilalt and Marder of southern Morocco has been intensively studied by WENDT et al. (1984) and WENDT (1988, 1989) but there is little available Information on the often rich ammonoid faunas in their sections. Late Famennian (UD VI to VI) ammonoid occurences of the Marder are briefly mentioned in TERMIER (1936: Fezzou), TERMIER & TERMIER (1950: Fezzou, including Disco. cucullata), CHOUBERT et al. (1952: Fezzou), HOLLARD (1958: Fezzou, 1960: Arho-n­ Kou) and PETIER (1959: Fezzou, including Lobotornoceras delepinei PETIER and Disco. cucullata). Only HOLLARD (1970) gave a rough faunal sequence and more extended species list of the famous Fezzou area and mentioned Lobotornoceras ranging into the upper part of the Wocklumian (UD VI-D, with Wocklumeria itself). The inadequate knowledge of the fine haematized faunas from north of Fezzou eventually allowed one of the frauds of V.J. Gupta, who lured H.K. ERBEN into a joint publication (GUPTA & ERBEN, 1983) on an alleged "Late Devonian ammonoid faunule from Himachal Pradesh" (see discussion in TALENT et al., 1988). Beyond any

R.Th. doubt, the supposed Hlmalayan haematitic material came originally from one of the Marder localities north of Fezzou or to the east at the Jebel Aguelmous (Text-Fig. 1). New torno­ ceratacean material comes from the following sources (other associated goniatite and clymenid groups are still under study and detailed taxonomy and biostratigraphy of these will be published elsewhere): 1. Jebel Aguelmous, N of Fezzou, ca. 1 km NE of the village (EBBIGHAUSEN locality 54), Upper Hembergian to Wocklumian. 2. Jebel Aguelmous, NW of EI Mbidia (Ebbighausen locallty 123), Dasbergian to Wocklumian. 3. Taourart, 11 km south of Fezzou, ridge along the track to Lahfira (EBBIGHAUSEN locality 85), Upper Hembergian to Wocklumian. 4. Aich Bou Kourazia, northern slope of the hills just south of the Jebel Oufatene, part of the Alt ou Nebgui, ca. 5 km W of Lahfira (EBBIGHAUSEN locality 154), Upper Hembergian to Dasbergian. 5. Jebel Merakeb (Mrakib), 28 km SE of Fezzou, ridge south of the track (north of the Oued el Ma'i'der; EBBIGHAUSEN locality 102a), Upper Hembergian. For comparison a large number of collections from other localities around the globe were available (see discussion in Section 4.): 1 . Rhenish Slate Mountains: unpublished collections from Effenberg (details see KORN & LUPPOLD, 1987), Enkeberg (WEDEKIND, 1908; BECKER, 1993b), Bergisch Gladbach (collections of H. PRESCHER and V. EBBIGHAUSEN), Hasselbachtal (BECKER, 1995 in press), and the Nie Brickwork Quarry (BECKER, 1985); Reitenberg collection of BECKER (1992). 2. Tafilalt, southern Morocco: unpublished late Famennian collections from Bou Tchrafine, Harnar Laghdad, Dar Kaoua, Bine Jebilet and Jebel lhrs {localities see BECKER, 1993b). 3. Hercynian Morocco: unpublished terminal Devonian ammonoid fauna from south of Ben Slimane (leg. BECKER & HOUSE, 1994). 4. Montana: unpublished topotypic material from the Three Fork Shale (see RAYMOND, 1909). 5. Canning Basin, Western Australia: large unpublished collections (leg. BECKER, HOUSE & KIRCHGASSER) from the Virgin Hills and Piker Hills Formations (see PETERSEN, 1975).

Taxonomy and Evolution of Tornocerataceae (Ammonoidea)

/ / I

/ I

I

450

'

\

' ........ "

'\

609

Fig. 1: Late Famennian Tornocerataceae localities in the Marder, southem Morocco. 54 = Jebel Aguelmous N of Fezzou, 123 = Jebel Aguelmous, NW of EI Mbidia, 85 = Taourart, 154 = Aich Bou Kourazia, 102a = Jebel Merakeb (Mrakib).

430

\

\

\ !

~

530

550

3. Taxonomy

Derlvatlo nomlnls: Due to the extreme flattening

Abbreviations: dm

= diameter, wh = whorl

height, ah = apertural height, ww = whorl widths, uw = umbilical width, A-lobe = adventitious lobe, V-lobe = external lobe, L-lobes = lateral lobes around the umbilicus (in the Goniatitida) . Shell parameters are either given in mm or in%. All measurements have a subjective error of 0.1-0.2 mm. An asterix in the synonymy lists stand for first records from new localities and regions. Be and Oe material will be housed in the Museum für Naturkunde, Berlin. Eb-numbers refer to specimens in the collection of V. EBBIGHAUSEN; MNHP stands for the Musee d'Histoire Naturelle, Paris, GPIG for the Institut of Geology and Palaeontology Göttingen.

Superfamily Tornocerataceae ARTHABER, 1911 Family Tornoceratidae ARTHABER, 1911 Subfamily Tornoceratinae ARTHABER, 1911 Tribus Aulatornoceratini BECKER, 1993b Planitornoceras n.gen. e.p. e.p.

1918

e.p.

1971 1992 1993b

e.p. e.p.

1959

PseudoclymeniaWEDEKIND: 137-138 Tornoceras (Protomoceras) PETIER: 201 Polonoceras BOGOSLOVSKIY: 61-62 Pernoceras BECKER: 20-21 Pernoceras BECKER: 221

Type-specles: Planitornoceras pugnax n.gen. n.sp.

/

of conchs.

Dlagnosls: Shell extremely compressed, flanks always flat, venter tabulate to slightly bicarinate, umbilicus open, subinvolute to subevolute, without ventrolateral spiral grooves but with broad spiral depressions in some species; without any constrictions. Growth lines strongly biconvex with characteristic, prominent and asymmetric ventrolateral salient which ascends prorsiradiately on the flanks and deflects into the deep ventral salient at the angular ventral edges. Interna! mould with distinctive ventral band. Suture with relative short dorsolateral saddle with a subangular transition to the shallow, widely rounded, asymmetric adventitious lobe which is as wide or wider as the lateral saddle; ventral saddle and lobe small. lncluded specles: Planitornoceras pugnax n.gen. n.sp., Plani. euryomphalum (WEDEKIND), Plani. weissi (WEDEKIND), Plani. transuralense (NALIVKINA), Plani. n.sp. aff. transuralense (= transuralense BECKER, 1985, 1992), Plani. n.sp. 1 (UD 11-0 of Harnar Laghdad, Tafilalt), Plani. n.sp. II = Pseudoclymenia planidorsata WEDEKIND (1918: PI. XVII, Fig. 4), Plani. n.sp. aff. weissi (Lower Hembergian of Enkeberg: related to weissi but more evolute).

BECKER, R.Th.

610

a a

b C C

d

e

d

f

e g

Fig. 2: Sutures of various Aulatornoceratini (b-d reversed for comparison). a. Plani. pugnax n.gen. n.sp., holotype, Be 1341 Aich Bou Kourazia, at 6.2 mm wh. ' b. Plani. cf. transuralense, MNHU specimen, Enkeberg, at 8.1 mm wh. transuralense, 1447/3611, after c. Plani. BOGOSLOVSKIY (1971, Fig. 12e), at 11 mm wh. d. Plani. euryomphalum, Be 1342, Jebel Merakeb, at 4 mm wh. e. Armatites beatus BECKER, paratype, Be 889/1 O, Dar Kaoua, Tafilalt (UD 11-D), at 5.3 mm wh. Species with still rather wide A-lobe. f. Armatites planidorsatus, Be 1158/1, Harnar Laghdad, Bed Fa 3, Tafilalt (UD 11-D), at 5.3 mm wh. A-Lobe significantly narrower than in any P/anitornoceras n.gen. e. Pemo. cf. crebriseptum, Oe 1585, Nie Brickwork Quarry, northern Rhenish Massif, at 8.9 mm wh. Suture similar as in

Planitornoceras-species.

Fig. 3: Growth lines of various Aulatornoceratini (d-e reversed for comparison). Pointed areas = of lateral furrows and depressions; vertical lines give the position of ventral edges. a. Plani. pugnax n.gen. n.sp., holotype, Be 1341, at 7.5 mm wh. b. Plani. euryomphalum, Be 1342, at 4 mm wh. c. Plani. cf. transuralense, MNHU specimen, Enkeberg, at 9.7 mm wh. d. Armatites planidorsatus, Be 1158/1, at 6.8. mmwh. e. Pol. subundulatum, Be 769/1, NehdenSchurbusch, at 2.9 mm wh, with typical highly projecting ventrolateral salients.

Discusslon: Nehdenian Aulatornoceratini have been revised by BECKER (1993b). Armatites embraces the very homogenous Goniatites planidorsatus Group which has extremely compressed whorls with flat flanks and tabulate to bicarinate venter. A ventral band shown on moulds and ventral flares or spines are strongly developed. Sutures are characterized by prominent dorsolateral saddles and deep A-lobes which are always narrower than the dorsolateral saddle (Text-Fig. 2e-f) . In new, undescribed Nehdenian species the latter becomes lingulate or even asymmetrically pointed. The ventral saddle

Taxonomy and Evolution of Tornocerataceae (Ammonoidea) is well-rounded. Both the sutural evolution and the development of strong constrictions show trends in the lineage as seen also in Linguatornoceras. Growth lines have a characteristic high, relative broad ventrolateral salient which ascends prorsiradiately on the outer flank and which flexures backwards right at the ventral edges. There are no narrow spiral furrows but broad spiral depressions, e.g. in Arm. lateroconcavus DYBCZYNSKI (see BECKER, 1993b). Polonoceras differs markedly and shows an opposite trend in sutural evolution which led to species with very short, low dorsolateral saddles which have an angular transition to the very wide adventitious lobes occupying most of the flanks. There are species with rounded, suboxyconic, and tabulate to bicarinate venter; the ventral band is either strong or secondarily reduced (Pol. mensinki BECKER). Growth lines display the narrow and tongue-shaped, very high ventrolateral salient of ancestral Aulatornoceras (TextFig. 3e; PI. 2, Fig. 1; compare BECKER, 1993b: Fig. 78) with the apex placed on the outermost flanks, even in tabulate forms with ventral edges such as Pol. subundulatum (FRECH). Apertures obviously had very delicate protruding lappets which had to be stiffened by narrow spiral furrows or double furrows. While both Polonoceras and Armatites are restricted to the Nehdenian, there is a third, closely related lineage ranging throughout the Famennian which combines sutures resembling Polonoceras (adventitious lobes as wide or wider as the lateral saddles, Text-Fig. 2a-d) with the growth line pattern and shell form of Armatites. In comparison to Polonoceras its main apomorphies lie in the broadening of dorsolateral and ventrolateral growth line salients and in the Jack of ventrolateral furrows. In some members the ventral band is secondarily slightly reduced and this led BECKER (1992) to include Plani. euryomphalum and relatives in Pernoceras. In. a more conservative approach the three genera discussed may be separated at subgeneric level only. However, all three groups are clearly defined, include a number of different species, and form lineages with different evolutionary trends at different times (Text-Fig. 9). Despite the relative small differences it is recommended here to express recognized phylogenetic trends of morphological specialisation in taxonomy. Planitomoceras n.gen. seems to have been derived from transitional forms between Pol. subundulatum and Armatites. By comparison with the latter two shorter-ranging taxa, however, the new genus remained rather conservative in terms of shell form and sutural evolution over a lang time-span. After the decline of other Aulatornoceratini it became the dominant genus of the tribe in the Prolobites delphinus Zone (see Section 4). Pernoceras lacks flares or spines on its mostly flat but rounded venter and is probably

611

derived from Planitornoceras species with a reduced ventral band. The type-species, Perno. kochi (WEDEKIND}, has a lingulate A-lobe, but there are more primitive and slightly older species such as Perno. delepinei (PETERSEN) and Tornoceras dorsatum WEDEKIND with sutures similar to that in Planitornoceras n.gen. (compare Text-Fig. 2g). Protornoceras and Tornia were derived from the delepinei Group by further reduction of all elements of the outer suture. In the Saoura Valley of southern Algeria occurs a very involute, tabulate Planitornoceraslike goniatite with very pronounced dorsolateral rather than ventrolateral salient of growth lines, unlike other members of the Aulatornoceratini. Unfortunately its suture is not known. This form may be generically distinctive. NALIVKINA (1953) described a similar form as Tornoceras aff. subundulatum from the Mugodzhar Mountains. Distribution: Rhenish Slate Mountains, Harz Mountains, Fichtel Mountains, Holy Cross Mountains, Mugodzhar, southern Morocco, southern Algeria, NW Australia. Stratlgraphical Range: Lower Nehdenian (UD 11D) to Wocklumian (UD VI) .

Planitornoceras pugnax n.sp. Text-Fig. 2a, 3a, PI. 1, Fig. 1-2 Type: Holotype Be 1341 (leg. V. EBBIGHAUSEN). Type locallty: Rich Bou Kourazia, southern Ma'ider, Morocco. Type level: Haematitic Fezzou Shales, Upper Hembergian or Dasbergian (UD IV to V). Derivatio nominls: From Latin pugnax = aggressive; due to the ventral band indicating the presence of spines). Material: The holotype and related specimens of the transuralense Group from Ettenberg (Be 1326) and Enkeberg (MNHU). In addition there is material of Plani. n.sp. aff. transuralense from the Nie Brickwork Quarry N of lserlohn-Letmathe. Dlagnosis: Flattened whorls with a shallow, spiral depression of the outer flanks, fast expanding; venter tabulate to slightly bicarinate, bordered by sharply angular edges, ww ca. 23 % dm. Ventral band well developed on internal mould. Sutures with moderately broad, low lateral saddle, wide asymmetric adventitious lobe which ascends straight and oblique to a low ventral saddle. Descrlptlon: The holotype is a well-preserved, complete haematitic mould with a small part of the body chamber preserved. About at the beginning of the latter the venter develops a very shallow median furrow; the ventral band is marked by shallow depressions and best seen in the apical whorl part. The complete outer flank (after ca. 3.5 mm wh) is occupied by a shallow

612

No. Be 1341 Be 1326

BECKER,

dm 16.1 ca.34

wh 7.2 ca.13

ah 5.2

ww 4.9 8.3

R.Th.

uw 3.7 9.7

wh/dm 44.7 38-39

ah/dm 32.3

ww/dm 30.4 ca.24.5

uw/dm 23 ca.28.5

Table 1: Dimensions of Plani. pugnax n.gen. n.sp. (Be 1341) and Plani. cf. transuralense (Be 1326). spiral depression. On the mould there are fine spiral striae which terminate just after the last septum. These structures are perhaps trecking bands of a large ventrolateral retractor muscle. Growth lines are illustrated in Text-Fig. 3a. Dimensions: (see Table 1). Remarks: The new species is close to Plani. transuralense but differs in its shallower spiral depression on the internal mould, by oblique, straight ascending rather than rounded ventral saddles which are also significantly lower than the lateral saddles (see Text-Fig. 2a-c), and by narrower ventral lobes which are deeper than the A-lobes. The Ma'ider specimen is also more involute than typical transuralense (25-27 % dm; and Fig. 11 a in compare statistics BOGOSLOVSKIY, 1971). A convolute and tabulate fragment (Be 1326; PI. 1, Fig. 5-6) from the Dasbergian of Ettenberg has similar weak spiral depressions on both flanks and growth lines as in typical Planitornoceras but it is more evolute than pugnax n.sp. Although the suture is not preserved, the ornament rules out affinities with other contemporaneous tabulate ammonoids such as Gonioclymeniaceae or early kosmoclymenids. A well-preserved P/anitornoceras with weak spiral depressions from Enkeberg (PI. 1, Fig. 3-4) deposited in the MNHU has a relative umbilical widths of 25-26 %. lt shows sutures (Text-Fig. 2b) with rounded adventitious lobes and subangular ventral saddles (caused by the ventral edges) resembling Plani. tranuralense (see Text-Fig. 2c). Currently both specimens from Ettenberg and Enkeberg are referred with cf. to the latter. In the delphinus Zone of the Letmathe area there is another new species of the transuralense Group (PI. 1, Fig. 11-12) with strong spiral depressions which remains tabulate (rather than bicarinate) throughout ontogeny and which is more compressed than related forms. Distribution: Ma'ider. Stratigraphical range: At Rich Bou Kourazia haematitic faunas contain index species of the Upper Hembergian to Lower Dasbergia.~ such as Platyclymenia (Platy.) annulata (MUNSTER), Prionoceras divisum (MÜNSTER) , Biloclymenia laevis (RICHTER), and Cymaclymenia striata (MÜNSTER).

Planitornoceras euryomphalum (WEDEKIND, 1918) Text-Fig. 2d, 3b, PI. 1, Fig. 7-10 •+v

1918

1954

•e.p.

1959

ve.p.

1992

Pseudoclymenia planidorsata var. euryomphala WEDEKIND: 138, Textfig. 34e, PI. XVII, Fig.2 Tornoceras (Protornoceras) planidorsatum euryompha/um FUHRMANN: 636, 642 Tornoceras (Protornoceras) planldorsatum var. euryomphala PEITER: 203, PI. XV, Fig. 4-5 Pernoceras euryomphalum BECKER: 21, PI. 1, Fig. 5b-c (Lectotype, NON Fig. 5 a = Plani. n.sp. II)

Type: Lectotype GPIG 389-32, designated in BECKER (1992: p. 21). Type locality: Enkeberg, eastern Rhenish Slate Mountains. Type level: Upper Nehdenian (according to WEDEKIND, 1918: explanation to PI. XVII). Material: The lectotype, one specimen from Jebel Merakeb (Be 1342, leg. EBBIGHAUSEN), one specimen from the Canning Basin, Australia. Dlagnosis: Venter tabulate to bicarinate (at adult stages), whorls fast expanding, ww 28-30 % dm, ventral band somewhat reduced with dense and short seals on the internal mould. Sutures with low, moderately broad dorsolateral saddle, shallow, widely rounded adventitious lobe and low, rounded ventral saddle. Description: The Ma'ider specimen shows relative typical sutures (Text-Fig. 2d) but the ventral saddle is not well rounded. The course of the growth lines is illustrated in Text-Fig . 3b. They are undulose an the outer flanks which grade with rounded edges into the flat venter. At 12.5 mm dm there are already 5 1/4 whorls; the protoconch is visible at the base of the umbilicus and very small (only 0.2 to 0.3 dm). Since the second growth constriction cannot be recognized without breaking the specimen, the size of the ammonitella remains uncertain. Sutures of the first whorl are prorsiradiate an the flanks. On the 2nd and 3rd whorl there is a rather wide lateral lobe outside the umbilical seem. During the 4th whorl it is gradually replaced by the typically shaped dorsolateral saddle which declines directly to the umbilical seem in later stages. Remarks: Plani. euryomphalum is the most evolute species of the genus. There are two new related forms in the Nehdenian and Lower

Taxonomy and Evolution of Tornocerataceae (Ammonoidea)

No. GPIG 389-32 GPIG 389-32 Be 1342 Be 1342

dm 42 36.5 12.5 8.9

wh ca.19 5.8 3.8

ah 13.1 3.8

WN

uw

8.5 8.1 3.6 2.9

12.2 10.3 ca.3.4 2.6

wh/dm ca.45

ah/dm 31.2

46.4 42.7

30.4

613

ww/dm 20.2 22.2 ca.27 32.6

uw/dm 29 28.2 28.8 29.2

Table 2: Dimensions of Plani. euryomphalum (Göttingen lectotype and new specimen). Hembergian which will be described elsewhere. They both lack spiral depressions but differ by narrower umbilici and suture line patterns. Distribution: Rhenish Slate Mountains, Harz Mountains, southern Morocco (Marder), southern Algeria (Saoura Valley), Canning Basin. Stratigraphlcal range: Upper Nehdenian to Upper Hembergian. Tribus Falcitornoceratini BECKER, 1993b

Gundolficeras n.gen. e.p. e.p.

1936 1985 1985

e.p.

1993b

Lobotornoceras SCHINDEWOLF: 689 ?"Lobotornoceras' PRICE & HOUSE: 161 "Lobotornoceras' PRICE & HOUSE: TextFig. 1 Falcitornoceras BECKER: 202-203

Type-species: Lobotornoceras bicaniculatum PETIER, 1959. Derlvatlo nominls: The new genus is named in honour of Univ.-Prof. Dr. Gundolf ERNST, Free University Berlin, for his contributions to paleontology and event-stratigraphy. Gundolficeras is one of the Famennian goniatites that shows especially weil event-controlled lateral and vertical distribution (see Sections 4 to 5). Dlagnosis: Shell compressed or somewhat inflated, tegoid, sometimes with ventrolateral furrows, umbilicus closed or opens at median stages. Growth lines strongly biconvex throughout ontogeny; without ribbing. Sutures with small secondary lateral saddle at the umbilical seem, widely rounded, subumbilical outer lateral lobe, high mid-flank saddle, narrow, asymmetric, rounded or pointed adventitious lobe and small ventral lobe. Sutural formula: EALv:~I. lncluded species: Gund. bicaniculatum, Gund. escoti (FRECH), Gund. att. escoti (e.p. escoti JUX & KRATH, 1974), Gund. n.sp. aff. delepinei (= bicanicu/atum BOGOSLOVSKIY), Gund. delepinei (PETIER), ?Gund. n. sp. (= TERMIER & TERMIER, 1950: PI. CXLII, Fig. 23-25). Remarks: HOUSE & PRICE (1985) revised Lobotornoceras SCHINDEWOLF from the Middle Frasnian Büdesheim Shales of the Eifel Mountains and showed that it is an evolutionary side-branch of the Tornoceratidae which is unrelated to all Famennian forms which previously had been assigned to that genus.

Lower Nehdenian tornoceratids with peculiar falcate ribbing (PI. 2, Fig. 22-23) and divided lateral lobe were descibed as Falcitornoceras. BECKER {1993b) showed that adult stages have smooth shells and illustrated earliest whorls of Lobot. bilobatum (WEDEKIND) which are very close to or identical with Fa/cit. falciculum wagneri HOUSE & PRICE. Consequently Falcitornoceras was emended to include all former Famennian lobotornoceratids. However, there are three different, parallel phylogenetic lineages with partly polyphyletic ancestry and which show diverging evolutionary trends during all of the Famennian. New collections from the Canning Basin confirm the idea that Falcit. korni BECKER belongs to an always unribbed genus which was derived independently from Phoenixites. In the korni Group the subdivision of the lateral lobe always remained inconspicuous whilst the adventitious lobe was elaborated in a number of new, still undescribed forms. Lobot. bicanicutatum (see below) differs from all other Falcitornoceratini by its open umbilicus and, as in other Devonian ammonoids, this morphological feature alone would justify generic separation. However, it is related to other species with very wide outer lateral lobes and narrow, asymmetric A-lobes which are all included in the new genus. In comparison with the ancestral Fa/cit. falciculumbilobatum lineage, the reduction of ribbing of early stages has continued to their complete loss (e.g., PI. 2, Fig. 20-21). Gundolficeras n.gen. differs trom Falcitornoceras in a similar way as Linguatornoceras differs from Tornoceras but its type-species is additionally distinguished by the late ontogenetic opening of the umbilicus. Taxonomie distinction between Gundolficeras and Falcitornoceras is supported by the fact that both genera range as separate bradytelic and parallel lineages throughout most of the Famennian. Distribution: Rhenish Slate Mountains, Thuringia, Graz area, Carnic Alps, Montagne Noire, Hercynian Morocco, southern Morocco, southern Algeria, Holy Cross Mountains, Novaya Zemlya, southern Urals. Stratigraphical range: Lower Nehdenian (UD 11D) to Upper Wocklumian (UD VI-D).

614

BECKER,

No. Be 1332/2 ds 8318-5 Eb-C3 old holotype Be 1328 Be 1332/1

dm 6.3 6.3 6.6 9 11.2 16

wh 3.6 3.8 3.7 5 5.9 8.9

ah 2.1 2 2 3.9 5.5

R.Th.

WN

uw

ca.3.8 3.9 3.9 5.5 6.6 9.1

ca.0.1 ca.0.2 ca.0.2

1.2 1.6

..

wh/dm 57.1 60.3 56.1 55.6 52.7 55.6

ah/dm 33.3 31.7 30.3 34.8 34.4

ww/dm 60.3 61.9 59.1 61.1 58.9 56.9

uw/dm ca.2 ca.3 ca.3 10.7 10

Table 3: Dimensions of Gund. bicaniculatum (lost old holotype replaced by neotype Be 13:28 herein). Gundo/ficeras bicaniculatum

(PETTER, 1959) emend. Text-Fig. 4a-b, ?4c, PI. 2, Fig. 16-21 •v cf.

1947 1950

+

1959 1968

'?

1970 1970

' NON

1971

\

~ff"'

\J

~ a

Tornoceras (Aufatornoceras) undulatum FLÜGEL: 191-192 Lobotornoceras sandbergeriTERMIER: 51, PI. CXLII, Fig. 29-31 [NON Fig. 20-22, NON Fig. 23-25 = ?Gundofficeras n.sp., NON Fig. 26-28 = Sphaeromanlicoceras cf. orbicutum Lobotornoceras bicanicufatum PEITER: 208-209, PI. XV, Fig. 12, 12a-b Lobotornoceras bicanicutatum STASCHEN: 42, Fig. 15 Lobotornoceras sp. HOLLARD: 924 Lobotornoceras bicanicufatum HOLLARD: 928 Lobotornoceras bicaniculatum BOGOSLOVSKIY:80-82, Fig. 20, PI. IV, Fig. 3 [= n.sp. aff. defepine~

Type: The holotype (by monotypy) of PETTER (1959 ;: specimen figured by TERMIER & TERMIER, 1950) could not be found in Spring 1986 in the Musee d'Histoire Naturelle, Paris, and has not been located since. In order to establish taxonomic stability for the genus, a Moroccan neotype (Be 1328) is selected here which displays all morphological features given by PETTER. Type locality: The original came from Oued Aricha, Morrocan Meseta; the neotype is from NE of Fezzou, Ma'ider. Type level: The Oued Aricha specimen came probably from the Upper Hembergian (UD IV) since it was found associated with Platyclymenia (TERMIER, 1936: 376). The majority of haematitic Fezzou (the source of the neotype) ammonoids seem to come from the Upper Hembergian and Lower Dasbergian. Material: Six specimens from Fezzou (Be 1328, ?1330, 1332/1-2, Eb-C3, MHNP ds 8318-5), one specimen from Jebel Merakeb (Eb-C16). Diagnosis: Whorls inflated and tegoid, adult WN exceeds 50 % dm, umbilicus closed at early stages but opens during ontogeny up to values of ca. 10 % dm, umbilical wall very steep, fl attened and deep, bordered by subangular umbilical edges; with well-defined ventrolateral spiral grooves which become shallower in the adult. Sutures with very wide and rounded Lv-lobe,

Fig. 4: Sutures of species of Gundolficeras n.gen. a. Gund. bicaniculatum, neotype, Be 1328, Fezzou,·Ma'i'der, at 6.4 mm wh. b. Gund. bicaniculatum, Be 1332/2, Fezzou, at 2.7 mmwh. c. Gund. ?bicaniculatum, Eb-C:3, Fezzou, at 2.2 mmwh. d. Gund. delepinei, neotype, IMNHP ds 8318-2, Fezzou, at ca. 5 mm wh. e. Gund. delepinei, neotype, at 2.8 mm wh. t. Gund. delepinei, topotype, IMNHP ds 8318-4, Fezzou, at ca. 6.5 mm wh. g. Gund escoti, lectotype, MNHU, La Serre, Montagne Noire, at 17 mm wh.

prominent subrectangular rnid-flank saddle, asymmetrically rounded A-lobB, moderately low, flattened ventral saddle and small, narrow ventral lobe.

Taxonomy and Evolution of Tornocerataceae (Ammonoidea)

Descriptlon: The neotype is a well-preserved haematitic mould which is septate throughout and which shows the septal face adorally. As in all other specimens, the flanks are rounded but converge strongly to a relative narrowly rounded venter. The deep umbilical wall, umbilical edges and umbilical opening are very characteristic. Spiral grooves become very shallow between 8 and 10 mm dm. In smaller specimens they are more prominent and they may disappear already at ca. 6 mm dm (Be 1332/2). In oblique view the umbilical edges falsely give the impression of a very low saddle developed at the umbilical wall. In strictly vertical view it is clear that the wide Lv has an almost straight base which rises to a low saddle sitting right at the umbilical seem, deep in the umbilical opening (Text-Fig. 4a). The ventral saddle has a flatly rounded top and is always lower than the mid-flank saddle. The spiral grooves lie at the base of the A-lobe (neotype) or at the ascending lateral pronge of the ventral saddle (PETIER's holotype). In Be 1332/2 the juvenile suture is the same as in the larger neotype (Text-Fig. 4b). In Eb-C3, however, there is a elevated mid-flank saddle which descends towards the umbilicus and which posseses a slide flexure (Text-Fig. 4c), resembling the sutural ontogeny of ?Exot. sylviae n.sp. (see below). There is either a lot of variability in the early ontogenetic formation of sutural elements, or EbC3 belongs to a new relative of the latter species. Growth lines of Eb-C3 are strongly biconvex with typical falcate course on the flanks. The narrow and projecting ventrolateral salient lies immediately in the spiral furrow. Dimensions (former holotype after PETIER, 1959): (see Table 3). Remarks: The Kazakhstan material of BOGOSLOVSKIY (1971: Fig. 20, PI. IV, Fig. 3) differs by a slightly wider adventitious lobe, by the closed umbilicus and less steep and characteristic umbilical walls. The sutural ontogeny clearly shows the subdivision of the lateral lobe by a small secondary saddle. lt seems to be a new species which is older and closer to Gund. delepinei than to bicaniculatum. Distribution: Moroccan Meseta, southern Morocco (Marder, Dra Valley), Rhenish Slate Mountains, cf. Austria. Stratigraphical range: Moroccan specimens came from the upper Hembergian (at least the specimen from Jebel Merakeb: UD IV NB) or possibly from the Dasbergian (HOLLARD, 1970: record from Rich-el-Beyat, associated with Maeneceras rotundelobatum (SCHINDEWOLF)). At Fezzou the species may range high in the Wocklumian (UD VI-D; HOLLARD, 1970). In the Rhenish Slate Mountains (STASCHEN, 1968) it is only recorded from the Annulata Event interval (UD IV-A).

615

Gundolficeras delepinei (PETIER, 1959) emend. Text-Fig. 4d-f, PI. 2, Fig. 14-15 1956 1956

·+

1959

NON

1970 1985

Lobotornoceras delepinei HOLLARD: 2752 [nom. nud.J Lobotornoceras delepinei HOLLARD & JACQUEMONT: 22 [nom. nud.] Lobotornoceras delepinei [CLARIOND mscr.] PETIER: 209, Fig. 47, PI. 15,Fig. 15 Lobotornoceras delepinei HOLLARD: 928 Lobotornoceras delepinei BARTZSCH & WEYER: 19-20, Fig. 4/4, PL. 1, Fig. 4 [=

Exotornoceras fezzouense n.sp.]

Type: Since the manuscript of CLARIOND was unpublished, PETIER (1959) became the author of the species. HOLLARD (1956) obviously was also aware of CLARIOND's work and recognized the taxen in the Dra Valley, but since no description was given, the species remained a nomen nudum until 1959. PETIER (1959) failed to specify a type but emphasized that CLARIOND's type came from Fezzou. An illustrated fragment from Ouarourout (southern Algeria) unwillingly became a syntype of PETIER but this was not found during a visit in 1986 to the Musee d'Histoire Naturelle in Paris. Due to the lack of any other syntype, and in order to establish taxonomic stability, a topotype from Fezzou (MNHP ds 8318-2) is selected here as neotype. Type locallty: Jebel Aguelmous N of Fezzou, Ma'ider. Type level: Main hematitic level of Fezzou Shales, UD V (according to PETIER, 1959: 209). Material: Three specimens from Fezzou (MHNP ds 8318-2-4). Diagnosls: Whorls inflated and tegoid, with strongly converging flanks; umbilicus closed but with steep, deep and rounded umbilical wall; no spiral furrows. Sutures as in Gund. bicaniculatum. Description: The neotype is a median-sized specimen which is fully septate but parts of the last whorl are broken oft. Shell morphology and sutures are identical with the description given by PETIER (1959). The flatly rounded, strongly converging flanks, the steep umbilical wall, and the asymmetrically rounded A-lobe are especially characteristic. Growth lines are not preserved but in oblique light traces of a high ventrolateral salient are visible. MHNP ds 8318-3 is a wellpreserved smaller specimen showing the septal face; ds 8318-4 is a !arger fragment which shows that the species was more compressed at later stages. Dimensions: (see Table 4) Remarks: Gund. delepinei is related to Gund. bicaniculatum but differs considerably in the closed umbilicus, the lack of distinctive spiral grooves (at least at observed ontogenetic stages), faster expanding whorls (higher wh values), and in the flatter, strongly converging flanks.

616

BECKER,

No.. dm MHNP ds 8318-2 14.4

wh 9.2

wd 8.4

R.Th.

wh/dm 63.9

ww/dm 58.3

Table 4: Dimensions of the Paris neotype of Gund. delepinei. No. lectotype

dm ca.33.5 28

carnicum

wh 19.8 16.4

ah ca.11

W-N

14.5 13.6

wh/dm ca.59 58.6

ah/dm ca.33

ww/dm ca.43 48.6

Table 5: Dimensions of types of Gund. escoti. Distribution: Southern Morocco (Marder, Dra Valley), southern Algeria (Saoura Valley) . Stratigraphical range: UD V to VI, possibly already in the UD IV.

Gundolficeras escoti (FRECH, 1887) emend. Text-Fig. 4g, PI. 2, Fig. 24-27 ?

1856

?

1887

•+v

1887

V

1894 1897 1902

•v+

1907

.•et. aff.

1911 1912 1914 1914 1921 1924 1924

•et.

1935 1936 1952 1954 1954 1965

V

1965

cf.

1971

aff.

1974

1985

•v

1992

Clymenia polytrichus RICHTER [ftde SCHMIDT, 1924) Goniatites (Tornoceras) n. sp. aff. curvispinae Frech: 372 Goniatites (Tornoceras) Escoti n.sp. Frech: 448 Tornoceras Escoti FRECH: 269 Tornoceras Escoti FRECH: 177i, Abb. C Tornoceras Escoti FRECH: 48, 109, Abb. 13b4, PI. 2, Fig. 19 Tornoceras Escoti var. camicum GORTANI: 26, PI. 6, Fig. 17a Tornoceras Escoti SOBOLEV: 37 Tornoceras Escoti SOBOLEV: 11 y-Gomi. 10 mm), tegoid, with well-rounded flanks, rapidly expanding (ah 34-41 % dm); ventrolateral furrows absent or very weak. Sutures with low but distinctive outer secondary lateral saddles, asymmetrically rounded, deep, narrow adventitious lobe and small ventral lobe. Descrlption: The holotype is a median-sized, well-preserved, fully septate haematitic mould which shows traces of strongly biconvex ornament in oblique light. Ventrolateral furrows are lacking or there may be only very faint traces of them. The outer secondary lateral saddle is already well-developed at 3.5 - 4 mm wh (e.g., Eb-C15) and its apex lies an the subangular umbilical edge. Be 1334 shows a rather strange sutural ontogeny (Text-Fig. 5h-j). Between 2.5 and 3 mm wh there is already a lobe at the closed umbilical seem and secondary shallow lobes form on the oblique, dorsad declining limb of a broad saddle between it and the already typically shaped Alobe. At the end of the whorl the septal face shows no difference to the other types. Dimensions: (see Table 7). Remarks: The new species seems to be closely related to Exot. fezzouense n.sp. but there are obviously marked differences in sutural ontogeny. Larger specimens of both taxa have more

620

BECKER,

No. Be 1333 Eb-C15 Eb-C14 ds 8318-1 Be 1334

dm 16.2 12.9 11 .6 9.8 8.6

wh 9.4 7.7 7.2 6.2 5

R.Th.

ww

ah 6 4.9 4.8 3.9 2.9

wh/dm 58 59.7 62.1 63.3 58.1

8.1 6.4 6.4 5 4.6

ah/dm 37 38 41.4 39.8 33.7

ww/dm 50 49.6 55.2 51 53.5

Table 7: Dimensions of types of ?Exot. sylviae n.sp.

8

Distribution: Rhenish Slate Mountains, Fichte! Mountains, Holy Cross Mountains, Urals (including the Mugodzhar Mountains), SW England, Montagne Noire, southern Morocco (Tafilalt, Ma'i'der), southern Algeria (Saoura Valley). Stratlgraphlcal range: Upper Nehdenian (UD 11H) to Upper Hembergian (UD IV-C).

Posttornoceras aff. contiguum (MÜNSTER)

~ '

Text-Fig. 7a-b, PI. 3, Fig. 1-2

d

Fig. 6: Sutures of ?Exot. sylviae n.sp. a. holotype, Be 1333, Taourart, at 8.5 mm wh;. b. paratype, Be 1334, Taourart, at 4.6 mm wh. c. paratype, Be 1334, at 3.6 mm wh; d. paratype, Be 1334, at 2.3 mm wh.

•+ aff.

dissimilar shell parameters than juveniles. At small size, however, the shallow ventrolateral furrows of Exot. fezzouense can serve in addition for identification. lf future material shows that the observed pattern of dorsolateral lobe origination of Be 1334 is typical, than sylviae may have to be placed in a new posttornoceratid genus characterized by a sutural formula as suggested for the whole group by WEDEKIND (1910): EA 1A2 LUI. The two modes of subumbilical sutural ontogeny exemplified by Exot. fezzouense n.sp. and ? Exot. sylviae n.sp. resemble the two modes of ventral lobe subdivision in the Pharciceratidae and Gephuroceratidae (CLAUSEN, 1971: Fig. 4). In Exot. superstes there are well-developed, deep L1v-lobes next to a high, weakly divided saddle at the umbilical seem (BECKER, 1993b) at 2.5 to 3.5 mm wh which suggests an ontogeny similar as in Exot. fezzouense n.sp. Distribution: Marder, southern Morocco. Stratlgraphlcal range: Not yet weil constrained.

V

Posttornoceras WEDEKIND, 191 O lncluded specles: Post. balvei w.~DEKIND (type-species), Post. contiguum (MUNSTER), Post. glenisteri PETERSEN, Post. sodalis n.sp. (= contiguum "SOBOLEV" in BOGOSLOVSKIY, 1971), Post. n.sp. (with spiral double furrows; Posttornoceratidae ?n.gen. n.sp. in BECKER, 1985: p. 27).

1832

Goniatites contiguus MÜNSTER: 22, Tal. 3, Fig. 8

aff. aff.

1839

?

1840 1840

?e.p.

1959

„

Goniatites contiguus MUNSTER: 48 Goniatites contiguus MÜNSTER: 108 Goniatites contiguus var. b. subcontiguus MÜNSTER: 108 [nom. nud.]

aff.

1993b

Sporadoceras posthumum PETIER: PI. XXII, Fig. 7 [only) Sporadoceras contiguum BECKER: 317318, Fig. 95j, PI. 26, Fig. 13-14 [further references]

Type: Neotype MNHU c.816/1, designated in BECKER (1993b: p. 317). While the Munich original of MÜNSTER (1832) has been lost there are other specimens f rom the type local[~Y in the MNHU which were identified by MUNSTER himself as Gon. contiguus. However, there is no reason to assume that these are syntypes since MÜNSTER continued his collecting after 1832 (MÜNSTER, 1839, 1840) and all these specimens are very dissimilar to his 1832 illustration. This is supported by comments on the 1832-original by GUMBEL (1862) and by the recognition of diverting forms in his contiguum-material by MÜNSTER (1840) himself who recognized a var. b. subcontiguus, which unfortunately was never / described. All MNHU specilJ1fill$., belonQ_!9_Jhe/ late Famennian Sporad. posthumuln-Groop. Type locallty: Schübelhammer, Fichtel Mountains; the neotype is from Enkeberg. Type level: The precise level of MÜNSTER's original is unknown; the neotype is from the contiguum Zone (UD 11-H). Descrlptlon: A single specimen (Eb-C2) from the Jebel Merakeb represents the first Posttornoceras from the Mader. lt is a complete, well-preserved haematitic mould with some shell traces and which is septate throughout. Adorally, the last

Taxonomy and Evolution of Tornocerataceae (Ammonoidea)

621

specimen gives additional hints that this is the case. The ontogenetic trend in Eb-C2 to extend the Lrlobe outside the umbilicus may justify taxonomic separation but this should be a substantiated by more material allowing insights into the intraspecific variability of the younger form. Poorly preserved Australian material of Post. glenisteri also shows somewhat variable sutures and this species is very close to the European-North African contiguum but slightly thicker at early stages (ww ~ 50 % at 20 mm dm). Apart from the obviously convex to weakly b biconvex ornament and Sporadoceras-type septa (BOGOSLOVSKIY, 1971), the homoemorphic Sporad. posthumum Group differs in better rounded, more prominent · saddles around the umbilicus (Text-Fig. 7c) and by even thicker whorls. Unfortunately, the Göttingen type of Sporad. posthumum has been lost and in the interest of taxonomic stability the selection of a C neotype from Hoevel or a neighbouring Sauerland locality is desired. PETTER (1959) described a posthumurrrfragment from the Lower Hembergian of Ouarourout which is.. perhaps a southern Algerian Post. contiguum (MUNSTER). NALIVKINA (1953) and BOGOSLOVSKIY 1 (1971) thought that SOBOLEV (1912b) had d established a new Posttornoceras contiguum which would not be a homonym as long as Gon. Fig. 7: Sutures of species of Posttornoceras and contiguus MÜNSTER and Post. contiguum Sporadoceras (band c reversed). SOBOLEV remain in different genera, which is obviously not the case. Already FRECH (1913, p. a. Post. aff. contiguum, Eb-C2, Jebel Merakeb, 31) stated that all or a part of known contiguum Ma"i'der, at 9.8 mm wh. specimens fall in Posttornoceras. Anyway, b. Post. att. contiguum, Eb-C2, at 5.3 mm wh. SOBOLEV did not create a new taxon which is c. Sporad. posthumum, MNHU!. specimen from evident by his quotation (SOBOLEV, 1914: p. 58) Schübelhammer included by MUNSTER in Gon. of "y-Gomi-dimeroceras (Posttornoceras) conti1 contiguus, at 6.8 mm wh. 1..1.t uo\.ir,1 eq,\l,~\'· '"' v (D :::, 0

:::;; :::, CD

Cl)

::Te. 0.

Sl) Cl> Sl) :::,

16....

(D ;:..:-

< :::!".

:::, :::, ..... 0 0. .... 0 0. Cl) ~ CD Sl)

..... Cl)

0. cg 6 CD~-· ro ff ö 0

§ ~-

s· Sl) 9.

Sl) Cl>

:::,

0

CD

)>

I

Uooer ()

(UD IV) 1

Falcit. n.sp. aff. bilobatum

()

I Middle

HEMBERGIAN )>

CD

(UD V) ()

DASBERGIAN )>

"" :::

()

~

(1) ()Q

0

:::

i•'"' ft'g·"' ~

CD

Lower t Upper

WOCKLUMIAN

~~

Sä

.,,

Post._glenisteri

(Mstr.)

>-

tti

.

!=tl

t~ ~

a

?A~~,p

tSlR~1R.

·········-········-·······-····················-

fä=. ""lfut

\\·---····-\ \\Alp. f"~l?; .... Ä[p kayse;i-\

conti J!!!l

.

f!?!!,$--!!!&!
..,

=· .. -· c..

~h

. . """ -----------------!re;;räir. escoti ..... - . -~ ·- - Gu•d '"~'""' ' ------· Gund ·-··n.sp. •ff: delepm" ······-··-===------::::::______________________ _________ -Gu'!..d d,1!J!;m; - - - ----------

Gund. escoti

C,

(IQ....,

::i.

~-~ 0

3"1;

"8

m

(UDVI)

ra Cl. lw _____ ....}_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ r;, l ·t b''-batum r------------------------------Falcit. n.sp .

CD

Lower

(UD 111)

--~-~---------------

····------ -

Gund. cf. escoti

Falcit. constrictum \ Falcit. falciculum

,

m

Gen. nov. (Falcit. korni Gp.) 'T. 11 subacutum Gp.

Ph. sulcatus

()

Falcit. falcatum

CD

NEHDENIAN (UDII)

0)

:::T

'....t

:0

::JJ

m

;,;:

CJJ m 0

CO

1\)

Taxonomy and Evolution of Tornocerataceae (Ammonoidea) At the end of the Lower Hembergian a significant extinction wiped out all pseudoclymenids and the majority of the Aulatornoceratini, especially Kirsoceras, Tornia and most or all true Protornoceras. Plani. euryomphalum survived obviously but so far there is no record from the UD 111-C. The type level of surviving Plani. weissi is in the delphinus Zone (WEDEKIND, 1908; assigned to Polonoceras in BECKER, 1985) and there are new forms such as Plani. transuralense (NALIVKINA, 1953) and n.sp. aff. transuralense (BECKER, 1985, 1992) in the Mugodzhar as weil as in the Rhenish Slate Mountains. Most Hembergian records of Tornoceras planidorsatum (see synonymy list in BECKER, 1993b) are referable to species of Planitornoceras. Pernoceras (included in Protornoceras by BECKER, 1985 and YATSKOV, 1994) forms only a minor constituent of ammonoid assemblages from the delphinus Zone of Germany, Novaya Zemlya, andin the Canning Basin. According to WEDEKIND (1908; compare FUHRMANN, 1954: p. 641 ), Perno. kochi, the type-species, came from this zone. ldentification of Hembergian tornoceratids as Tornoceras simplex (e.g., SCHINDEWOLF, 1923: p. 281; PETERSEN, 1975) is probably based on the occurence of falcitornoceratids or very involute pernoceratids with well-rounded venter such as Perno. crebriseptum. The latter occurs in the delphinus Zone of Germany (Nie Brickwork Quarry) and of Novaya Zemlya (YATSKOV, 1994).

4.3. Upper Hembergian (Prionoceras Stufe, UD IV) MENCHIKOFF (1930) recognized the presence of Falcit. bilobatum in the UD IV of southern Algeria (Ouarourout). Due to the lack of description the precise taxonomic position of this form in relation to the older types of the species remains unclear. The specimen f rom Marhouma (southern Algeria) illustrated by PETIER (1959) on PI. XV, Fig. 13 seems to be an Exot. fezzouense n.sp., a species which has been found in the UD IV at the Jebel Merakeb. A contemporaneous small specimen from the Piker Hills Formation of the Canning Basin differs from typical bilobatum in strenger shell compression and in the broader, very low secondary lateral saddle around the umbilicus. lt may be conspecific with a probably new Exotornoceras described from Thuringia by BARTZSCH & WEYER (1985: p. 19, Fig. 4/3, PI. 1, Fig. 2) as Lobotornoceras bilobatum. Kazakhstan UD IV material described by BOGOSLOVSKIY (1971) have rather narrow, asymmetric A-lobes similar as in Exot. fezzouense. Gund. escoti re-appeared in the Platyclymenia annulata Zone (UD IV-A) of the Rhenish Slate Mountains (BECKER, 1992) and somewhat higher (UD IV-B) in Thuringia (Bohlen, SCHINDEWOLF, 1952). A similar event-

629

controlled appearance applies to Gund. bicaniculatum which was found in the Annulata Event beds of Kattensiepen (Rhenish Slate Mountains; STASCHEN, 1968), in the UD IV of Herynian Morocco (Oued Aricha; TERMIER & TERMIER, 1950; PETIER, 1959) and, as mentioned above, at Jebel Merakeb, Marder. The precise entry level of Gund. bicaniculatum and delepinei at Fezzou is not known. The type of Post. balvei came from the Plat. annulata Zone of the Beul (northern Rhenish Slate Mountains; WEDEKIND, 1910). In its outwardly pointed, asymmetric A-lobe it is homoemorphic with Sporad. brachy/obum. A topotype of the latter (GPIG 390-707, Text-Fig. 7d) has rather fast expanding whorls as in Posttornoceras but shows a Sporadoceras-type septum. Unfortunately, ornament is not preserved. Convex growth lines are only known in similar Sporad. semiflexum and were illustrated by BOGOSLOVSKIY (1971; PI. X, Fig. 5). A Post. balvei record from the annulata Zone of Thuringia (MÜLLER, 1956) is based on erroneous identification of a compressed sporadoceratid with strong spiral ornament and shell fractures which caused the episodic formation of pseudobiconvex growth lines during repair (forma substructa HÖLDER, 1973). The pre- and postfracture sculpture is simply convex. SIMAKOV et al. (1983) gave evidence that Post. contiguum "SOBOLEV" (? = sodalis n.sp.) ranges throughout the Prionoceras Stufe in the Kia Section of the southern Urals. The new Ma'ider specimen described prove that close relatives of Post. contiguum (MÜNSTER) survived into the UD IV. These species should not be confused with the homoemorphic Sporad. posthumum Group (see PI. 3, Fig. 12-13) which entered late in the Upper Hembergian (UD IV-B; SCHINDEWOLF, 1952; BECKER, 1992) but which became more characteristic in the Dasbergian. According to BOGOSLOVSKIY (1971: 33), Alpinites appeared in Kazakhstan already in the upper part of the UD IV, in faunas dominated by Prionoceras and Praeglyphioceras with both Platyclymenia and Costac/ymenia present as weil {pointing to an UD IV-C age). In morphological terms, Alpinites appeares to be a descendant of Discoclymenia. The stratigraphical range and the specialized angular mid-flank saddle of Disco. cucullata, however, suggest that this species is not the ancestral form. There may be other, older true discoclymenids, perhaps hidden among the "Disco. seidlitzi" Group. Knowledge of Upper Hembergian Aulatornoceratini is based on very few faunas. The Three Fork Shale of Montana (RAYMOND, 1909) has yielded Tornoceras crebriseptum (= douglassi RAYMOND) which was revised by HOUSE (1965, 1970). New topotypic material (PI. 2, Fig. 2-3) gives evidence that the umbilicus is open at early stages (up to ca. 7 mm dm).

630

BECKER,

Subsequently the umbilicus gets narrower and is eventually almest closed but a typical wide umbilical wall develops. Open umbilicate whorls and a broad and high dorsolateral saddle place crebriseptum in close relationship of the Pernoceras delepinei Group. ANDERSON et al. (1974) mentioned the presence of Tornoceras in faunas with Platyclymenia from the Sierra Butts Formation of California. Possibly, this refers to another occurence of Pern. crebriseptum. In the Rhenish Slate Mountains, LANGE (1929) reported on the presence of Tom. (Prot.) planidorsatum in the annulata Zone of the Enkeberg. With high probability this refers to a species of P/anitornoceras n.gen. Plani. euryomphalum reappeared after a Middle Hembergian record gap in the UD IV of the MaYder (new record from Jebel Merakeb). This may be the precise level of Plani. pugnax n.sp. from neighbouring Rich Bou Kourazia. Planitornoceras n.gen also has been found in the Cymaclymenia Zone (Oe 1070, Bed 15/16, UD IV-B) of the Nie Brickwork Quarry (northern Sauerland; BECKER, 1985: det. Pol. (Pol.) cf. weiss1). Preparation of a poorly preserved specimen from somewhat higher in the same outcrop {Oe 1585, Bed 16b, UD IV-C} showed that it is not a relative of Falcit. bilobatum as quoted in BECKER (1985: p. 29) but a very involute Perno. cf. crebriseptum. Dasberglan (Clymenla!Gonloclymenla Stufe, UD V) Within Dasbergian Falcitornoceratini there were at least three species of Gundolficeras n.gen. FRECH (1887) recognized Gund. escoti in the Montagne Noire (at La Serre) and later (FRECH, 1894) as well in the Austrian Carnic Alps (Großer Pal). On the ltalian side, GORTANI (1907) added a record from the Monte Primosio. Later, SCHINDEWOLF (1921} recognized the same species in Thuringia (Bohlen). BARTZSCH & WEYER (1985) dated new material from neighbouring sections (Mühlfelsen, Unteres Mühltal) as lower Dasbergian (UD V-A). Dasbergian Gund. delepinei are only known from Gund. Fezzou (PETIER, 1959) whilst bicaniculatum occurs both in Algeria (Ouarourout; PETIER, 1959) and in Morocco (Rich-el-Beyat; HOLLARD, 1970). Dasbergian Exotornoceras are described here from Fezzou and seem to be present also in Thuringia (BARTZSCH & WEYER, 1985; UD VA) . Posttornoceras obviously died out at the end of the Prionoceras Stufe. lnstead there was a fast spread of cryptogenic Disco. cucullata which was already recognized in the last century in Thuringia (RICHTER, 1848: Gon. lenticularis; GÜMBEL, 1862: Gon. Hercynicus: ZIMMERMANN, 1914: Gon. {Sporad). cucullatus), in the Fichtel Mountains (MÜNSTER, 1840: Gon. Hauerr, FRECH, 1902: Sporad. cucullatum), and at La

4.4.

R.Th. Serre in the Montagne Noire (FRECH, 1887). Later, Dasbergian records from other regions were added: Carnic Alps (Kleiner Pal, FRECH, 1902), southern Algeria (Ouarourout and Ougarta: Dkissa and Bou Mehaiud, MENICHIKOFF, 1930; Saoura Valley: Zereg, PETIER, 1959), southern Urals (Aktyubinsk Oblast, EIOGOSLOVSKIY, 1971; eastern slope, STEPANOVA et al., 1985), and southern Morocco (Marder: Fezzou, TERMIER & TERMIER, 1950; Jebel Merakeb, leg. EBBIGHAUSEN; Tafilalt: Dar Kaoua [Be 132.7] and Bau Tchrafine; BECKER, 1993b). BRUGGE (1973: Alte Heerstraße Section, Thuringia) proved that the speci,es enters close to the base of the Dasbergian, whilst SCHINDEWOLF (1923: Kirchgattendorf, Fichtel Mountains) found it in the midc~[e part (UD V-B) with Ornatoclymenia ornata (MUNSTER). In the Rhenish Slate Mountains, oldest so far published material came from the Dasbea-gian/Wocklumian transition (Schießstand Section, Warstein Reet area; CLAUSEN et al., 1979), but Disco. cucullata occurs at other localities also in lower parts of the UD V (e.g., at Ettenberg, Bei 1324). As said above, there is currently no clearly intermediate species between PosttornocE,ras and Disco. cucullata. So far, only at Kia (sc,uthern Urals) and in the hypoxic Fezzou shales have both genera been recorded in direct succession. The type of Alp. kayse,ri was found by SCHINDEWOLF (1921) in the IDasbergian of the Carnic Alps and this may be the age of additional material from southern Algmia (Ouarourout; PETTER, 1959) and from the MaYder as described herein. The precisB age of a cf.specimen from Kowala in the Holy Cross Mountains (SCHINDEWOLF, 1944) is unknown. As discussed in the taxonomic part, some Tafilalt specimens of TERMIER & TERMIER (1950) may belang to a different species of Alpinites. So far, no Dasbergian member of the Aulatornoceratini had been described or mentioned in a faunal list. A relative of Plani. transuralense (Be 1326) was ,collected in 1994 from loose debris above the Annulata Event beds at Ettenberg. Associated loose1 material did not contain any typical late Hembergian form such as Prionoceras or Platyclymenia. According to KORN & LUPPOLD (1987: p. 202) the topmost Hembergian is generally rather poorly fossiliferous in that section. A post-Hembergian range of Planitornoceras n.gen. is supported by the finding of an isolated relative in the Wocklumian of Dzikowiec (Ebiersdorf) in Silesia (oral. comm., J. DZIK, Warszawa). 4.4. Wocklumlan (Wocklumer1la Stufe, UD VI) Wocklumian representatives olf Falcit. bilobatum from southern China (RUAN, 1981) surprisingly do not differ significantly from the much older types of the species which th13refore may have the langest range of all Famennian goniatites.

Taxonomy and Evolution of Tornocerataceae (Ammonoidea) Specimens of Lobotornoceras aff. bilobatum PETTER (1954) from southern Algeria (Ouarourout) unfortunately have not been described. The same applies to Wocklumian "Lobotornoceras sp." from Thuringia (Geipel Quarry; WEYER, 1981; UD VI-A/C) and the Rhenish Slate Mountains (Müssenberg; KORN , 1981; Wocklumeria sphaeroides Zone = UD VID). Gund. escoti was recognized by SCHMIDT (1924) in the Rhenish Slate Mountains (Eulenspiegel Quarry, Warstein area, and Wildungen, Kellerwald), and by PFEIFFER (1954) in the Lower Wocklumian (UD VI A/B) of the Bohlen Section (Thuringia). The Wocklumian range of Gund. de/epinei is based on material from the Dra Valley (southern Morocco; HOLLARD, 1956). PETTER (1959) mentioned another North African occurence at Foum el Aribi. Together with the specimen of KORN (1981), the youngest known Tornoceratidae come from the sphaeroides Zone of Fezzou (HOLLARD, 1970: perhaps Gund. bicaniculatum). There is also a Gund. cf. bicaniculatum in an alleged Nehdenian fauna (FLÜGEL, 1947: det. Tornoceras (Aulatornoceras) undulatum) from the Eichkogel near Graz (Austria) which seems to include Parawock/umeria. According to present knowledge, Disco. cucullata was the last undoubted member of the Posttornoceratidae. The types of the species (v.BUCH, 1839) came from Silesia where SCHINDEWOLF (1937: p. 21 -22) recorded it from the Parawocklumeria paradoxa Zone (UD VI-C; based on associated Glatziella glaucopis). Other Wocklumian occurences are from the Rhenish Slate Mountains (Müssenberg, SCHMIDT, 1922; Drewer, SCHMIDT, 1922; Oberrödinghausen, SCHMIDT, 1924; Wildungen, SCHMIDT, 1924, Hasselbachtal, BECKER, 1985: UD VI-A) , Thuringia (Bohlen, SCHINDEWOLF, 1952), and Guizhou (= Kweichow: Daihua Section), southern China (SUN & CHEN, 1965; YUAN, 1988, however, quotes a Lower Dasbergian age). SCHINDEWOLF (1937) showed that Disco. cucullata ranges practically up to the top of the Wocklum Limestone. The youngest, however questionable, record of a Alpinites comes from the paradoxa Zone (UD VI-C; KORN, 1981). Both the Tornoceratidae (with three or four lineages) .and the Posttornoceratidae (with one or possibly ·two lineages) fall victim to the global Hangenberg .mass extinction event (BECKER, 1993a; Text, F.ig. 10). '5.

Evolutlonary Ecology of Late Famennian Tornocerataceae , Constructional morphology and spatial and stratigraphical distribution patterns of Famennian Falcitornoceratini and their descendants, the Posttornoceratidae, give insights into paleoecological factors which controlled their evolution.

631

In this context the following aspects have to be considered: 1. Major morphological characteristics are: thin, fast expanding, strongly to moderately compressed shells with closed umbilicus and relatively short body chamber, apertural margin with deep, functional hyponomic and ocular sinus, ventrolateral salient of early to adult stages often stiffened by spiral furrows, little intraspecific variation of shell parameters, evolutionary tendency to more complex sutures with pointed lobes and saddles, ribbing absent or weak and restricted to juvenile stages, without elaborate shell thickenings and constrictions. 2. The group is mostly only an accessory element of studied Famennian ammonoid assemblages from the Tafilalt, Ma'i'der and Rhenish Slate Mountains (compare specimen numbers in Russian localities of BOGOSLOVSKIY, 1971). Abundance is typically low in cephalopod limestones of carbonate platforms (e.g., Tafilalt), carbonate ramps (e.g., Montagne Noire), intrabasinal seemounts (Rhenish Slate Mountains), nodular limestones of slopes as well as in hypoxic intra-shelf basins. Faunas with good record of very specific taxa are known from some haematitic shelf basin assemblages (e.g., Discoc/ymenia in the Marder) or from interlayers of turbiditic basinal sandstones of Thuringia (BARTZSCH & WEYER, 1985). 3. The stratigraphical record is punctuated. Individual species or complete lineages variously became Lazarus-Taxa for periods of different duration but re-appearance was often linked with transgressive pulses of global hypoxic events. With the Annulata Event, Pern. crebriseptum spread in North America, Plani. euryomphalum, pugnax n.sp., Exotornoceras and Posttornoceras appeared frequently in goniatite shales but not in cephalopod limestones of southern Morocco, and Gundo/ficeras spread with several species in the Rhenish Slate Mountains, Moroccan Meseta, southern Morocco and southern Algeria. Discoclymenia had almest pantropical distribution but it enters as a cryptogenic form. 4. Opportunistic blooms of Falcitornoceratini occured after significant extinction events. This is most evident by the immediate post-Keilwasser Event phase of the basal Famennian. Another example comes from the Canning Basin where a new Falcitornoceras species spread after the extinction of the Pseudoclymeniidae in the top part of the Lower Hembergian. Already HOUSE (1963: Fig. 1) illustrated some general shell similarities between involute tornoceratids and Recent Nautilus. All morphological characteristics of Falcitornoceratini and posttornoceratids point to a full pelagic lifestyle. The body chamber length of about three quarters of a whorl led to an upwardly oriented apertural position (TRUEMAN, 1941) when the

632

BECKER, R.Th.

body was retracted to the shell {which is assumed here to be a normal living position to allow maximal protection by the conch). The deep hyponomic sinus enabled horizontal and variable orientation of the hyponome. As outlined by JACOBS & LANDMAN (1993), the jet stream probably lay at about the same level as the center of mass which minimized rotational forces during propulsive movements. The involute, compressed smooth shell is moderately stream-lined and allowed slow active swimming in quiet hydrodynamic regimes as is known in Nautilus. Large ocular openings at the apertural margin illustrate that there was no need to protect the vulnerable flanks of the soft-body from benthic predators such as arthropodes. Vision was easily possible without stretching out off the shell. This is an important difference to Nautilus whose much reduced lateral sinus of the apertural margin is interpreted here as a protective adaption to seafloor feeding. In ammonoids it is widely known {e.g., KEUPP & ILG, 1992) that the frequency of shell injuries increases significantly with the intensity of bottom contact in epibenthic forms. Shell protection against free swimming predators such as early sharks and arthrodires obviously was less significant. lt is suggested that at least a part of the life-cycle of Falcitornoceratini and posttornoceratids was spent in the photic part of the water column where well-developed eyes would be needed. The trend to increase septal complexity and, therefore, septal and pellicle surface is explained by selection pressure which led to a higher speed of filling and emptying phragmocone chambers. Optimation of the hydrostatic apparatus would be most significant in forms which have to adjust frequently the body weight to various water depths. The whole group seems to have optimized the ability for quick vertical migration {compare interpretation in RUAN, 1991). Constraints for energyconsumptive active swimming in low-oxygen environments may have been a part of the selection pressure (FISCHER & BOTIJER, 1995). The spatial distribution and eustatically influenced stratigraphical appearance supports the interpretation of adolescent to adult Falcitornoceratini and Posttornoceratidae as fully pelagic groups which lived at various depths in the free water column. Phylloceratids, for example, are Mesozoic counterparts. Among Carboniferous goniatites, SAUNDERS & SWAN (1984) recognized a corresponding pelagic Morphotype 1, typified by anthracoceratids and dimorphoceratids. Early juveniles of the group probably were part of the plankton. With transgression distinctive taxa could migrate to larger shelf areas whilst during regressive episodes large parts of the cephalopod biofacies became too shallow for some species. The latter

forms became Lazarus Taxa for periods of various length. Survival obviously was possible in restricted, often hypoxic deeper-water environments at steep shelf slopes. FISCHER & BOTTJER (1995) recently highlighted the significance of low-oxygen biota for the episodic resettling of shallower environments by certain ammonoids and pelecypods. The rarity of assemblages dominated by Falcitornoceratini and posttornoceratids may to some extent reflect unfavourable diagenetic conditions of deeper water sediments (fast dissolution of aragonitic shells in shaly matrix). However, the lack of flattened tornoceratid faunas in basinal facies such as ostracod shales {Cypridinenschiefer Facies) with preserved pelecypods {mostly Guerichia) suggests that there was an upper water depth limit even for these forms. Maximum distances of cyclic {perhaps daily as in Nautilus) vertical migration from the vicinity of the seafloor to the photic zone may have been a delimiting factor for bathyal distribution. More important, perhaps, was the lack of appropiate food resources in the part of the open ocean between storm wave base and the lower depth limit controlled by osmotic capacities and/or by maximum pressure causing siphuncle and shell implosion. Constant vertical migration could also explain the vulnerability of various lineages to the major global events. During significant and very rapid regressions the ecospace was reduced considerably at the narrow outer shelf-oceanic basin transition. Species were caught in small areas barred by shallow shelves and too deep open ocean. There they became very dependent on the stability of other important paleoecological factors such as temperature and salinity gradients and the local food chain structure. Opportunistic faunal blooms after extinction events suggest that the population dynamics of Falcitornoceratini was also strongly influenced by competition with other ammonoid groups living in the free water column. Aulatornoceratini differ from Falcitornoceratini markedly by even more compressed, open umbilicate, subinvolute to evolute shells which have lesser hydrodynamic properties. A peculiar feature are the very small protoconches which seem to be less than half the size (in the range of 0.3 mm dm) of those as in Tornoceras (HOUSE, 1965), Falcitornoceras (HOUSE & PRICE, 1985) or in Discoclymenia. The frequent development of open, delicate ventral flares and spines, e.g. in Polonoceras, Aulatornoceras, Armatites and Planitornoceras n.gen., suggests living in the free water column rather than at the seafloor. The prevailing tendency to reduce the suture (excepting the Perno. kochi Group and Armatites) points to an adaptive strategy of slow bathymetric mobility. Therefore, the group is interpreted as vertically and horizontally slowly mobile mega-plankton which was confined to

Taxonomy and Evolution of Tornocerataceae (Ammonoidea) quiet hydrodynamic regimes, and surprisingly, to outer shelf areas. Among Carboniferous goniatites, SAUNDERS & SWAN (1984) assigned morphologically similar forms to their pelagic Morphotype III. The different paleoecology of Falcitornoceratini/Posttornoceratidae and Aulatornoceratini may explain the alternating phases of their evolutionary succes. Both thrived during transgressive episodes (e.g, the Lower Nehdenian adaptive radiation} while the latter persisted or even showed faunal blooms during prolonged global lowstand phases (e.g., Lower to Middle Hembergian}. Competition with descendant clymenid groups may explain why the Aulatornoceratini never fully recovered from the global end-UD 111-B extinction. Rapid regressions such as the Condroz Events and at the FrasnianFamennianand Devonian-Carboniferous boundaries (BECKER, 1993b) diminished the diversity of all Tornocerataceae. This probably happened due to a culmination of several factors such as the overall size reduction of ammonoid ecospace (species-areas) at the shelf margins, the introduction of high hydrodynamic events (e.g. storm waves), lethal increase in water temperatures in wide areas (if they were as sensitive to high temperatures as Nautilus), disruptions in the food chain and (at the Condroz Events} competition with other ammonoid groups which were better adapted to shallower water.

6. Acknowledgements With this contribution I wish to congratulate Prof. Dr. Gundolf ERNST to his 65th birthday. Warmest thanks are given to Prof. M.R. HOUSE (Southampton) for the enjoyable joint field work (partly within his NERC grants), comments and corrections of the manuscript. Dr. V. EBBIGHAUSEN (Odenthal} generously delivered his marvellous Moroccan collections for scientific investigation. Dr. Y. GAYRARD (Paris), Dr. H. JAHNKE (Göttingen) and Dr. J . HELMS (Museum für Naturkunde, Berlin) kindly made museum collections available. Dipl. Geol. D. KORN (Tübingen) supplied a copy of his unpublished manuscript on new sporadoceratids which includes a revision of the type-species of Posttornoceras. H. KEUPP (Berlin} provided literature on repaired shell fractures and discussed aspects of ammonoid paleoecology. This research was financed within a habilitation grant of the Deutsche Forschungsgemeinschaft (DFG}. 7. References ANDERSON, T.B., WOODWARD, G.D., scon, M. & TWICHELL, M.K. (1974): Geology of a Late Devonian fossil locality in the Sierra Buttes Formation, Dugon Point, Sierra City Quadrangle, California. - Geol. Soc. Am., Abstr. w. Progr., 6 (3): 139.

633

BARTZSCH, K. & WEYER, D. (1985): Zur Stratigraphie der Oberdevon-Quarzite von Saalfeld im Thüringischen Schiefergebirge. - Freib. Forsch.-H., C400: 5-36. (1986): Biostratigraphie der Devon/KarbonGrenze im Bohlen-Profil bei Saalfeld (Thüringen, DDR}. - Z. geol. Wiss., 14 (2): 147-152. BECKER, R.T. (1985): Devonische Ammonoideen aus dem Raum HohenlimburgLetmathe (Geologisches Blatt 4611 Hohenlimburg}. - Dortm. Beitr. Landeskd., naturwiss. Mitt., 19: 19-34. - (1992): Zur Kenntnis von Hemberg-Stufe und Annulata-Schiefer im Nordsauerland (Oberdevon, Rheinisches Schiefergebirge, GK 4611 Hohenlimburg}. - Berliner geowiss. Abh., (E), 3: 3-41. - (1993a}: Anoxia, eustatic changes, and Upper Devonian to lowermost Carboniferous global ammonoid diversity. - Syst. Assoc. Spec. Vol., 47: 11.5-163. - (1993b): Stratigraphische Gliederung und Ammonoideen-Faunen im Nehdenium (Oberdevon} von Europa und Nord-Afrika. Cour. Forsch.-lnst. Senckenberg, 155, 405 pp. - (1994): The onset of the global Famennian regression and ist evolutionary consequences. - Moscow Symp. "Devonian Eustatic Changes of the World Ocean Level", Abstr. Vol. : 7, Palaeont. Inst. RAS, Moscow. (1995, in press}: New faunal records and holostratigraphic correlation of the Hasselbachtal D/C-Boundary Parastratotype. - Ann. Soc. geol. Belg., M. Streel Festschrift. BEYRICH, E. (1859): Über die Unterscheidung der Goniatiten von den Clymenien. - Z. dt. geol. Ges., 11: 139-140. - (1884): Erläuterungen zu den Goniatiten L. v. BUCH's. - dt. geol. Ges., 36: 203-219. BÖHM, R. (1935): Etudes sur les Faunes du Devonien Superieur et du Carbonifere Interieur de la Montagne Noire. - 203 pp., Montpellier. BOGOSLOVSKIY, B.I. (1971): Devonskie ammonoidei. II, Goniatity. - Trudy Paleont. Inst., 127, 228 pp. BRÜGGE, N. (1973): Zur stratigraphischen Einstufung des Oberdevon-Profils ,Alte Heerstraße" bei Schleiz, Bezirk Gera. - Z. geol. Wiss., 1 (3): 319-327. BUCH, L. v. (1839): Über Goniatiten und Clymenien in Schlesien. - Abh. Akad. Wiss. Berlin, f. 1838: 149-169. CHOUBERT, G. (1952): Geologie de Maroc, Fase. 1, 2e partie. Histoire Geologique du

z.

634

BECKER, R.Th.

domaine de !Anti-Atlas. - Notes Mem. Serv. Geol. Maroc, 100: 77-194. -, CLARIOND, L. & HINDERMEYER, J. (1952): Livret-guide de l'excursion C36. Anti-Atlas central et oriental. - 19th Intern. Geol. Congr., sess. Alger 1952, ser. Maroc, 11, 89 pp. CLAUSEN, C.D. (1971): Geschichte, Umfang und Evolution der Gephuroceratidae {Ceph., Oberdevon) in heutiger Sicht. - N. Jb. Geol. Pal., Abh., 137 (2): 175-208. - , KORN, D. & UFFENORDE, H. (1979): Das Devon/Karbon-Profil am alten Schießstand bei der Bilstein-Höhle (Blatt 4515 Hirschberg, Warsteiner Sattel, Rheinisches Schiefergebirge). - Aufschluss, Sonderbd. 29 (Warstein): 47-68. FISCHER, A.G. & BOTTJER, D.J. {1995): Oxygen-depleted waters: A lost biotope and its role in ammonite and bivalve evolution. - N. Jb. Geol. Paläont., Abh., 195 (1-3): 133-146. FLÜGEL, H. (1947): Nachweis der Oberdevonstufe II im Grazer Paläozoikum. - Verh. geol. Bundesanst., 1947: 190-195. & KROPFITSCH-FLÜGEL, M. (1965): Catalogus Fossilium Austriae, Heft Vif4: Ammonoidea palaeozoica. - 31 pp., Vienna (Springer). FRECH, F. (1887): Die palaeozoischen Bildungen von Cabrieres (Languedoc). - Z. dt. geol. Ges., 39: 360-487. - (1894): Die Karnischen Alpen. - 515 pp., Halle. - {1897) : Lethaea palaeozoica. - Bd. 2 (1), 256 pp., Stuttgart. - (1902): Über devonische Ammoneen. - Beitr. Pal. Geol. österr-Ung., 14: 27-112. - (1913): Ammoneae Devonica (Clymeniidae, Aphyllitidae, Gephyroceratidae, Cheiloceratidae). - Fossilium Catalogus. 1. Animalia, 1: 1-42. FREYER, G. (1957): Neue Untersuchungen im Oberdevon des Vogtlandes auf Grund des Fossilinhaltes der Kalke im Bereich der Vogtländischen Mulde. - Freib. Forsch.-H., C27: 1-100. FUHRMANN, A. (1954): Petrographie, Fauna und stratigraphische Stellung einiger Aufschlüsse im Oberharzer Oberdevon, Blatt Zellerfeld und Riefensbeek. - Geol. Jb., 69: 629-652. GANDL, J. (1964): Erläuterungen zur Geologischen Karte von Bayern, 1 : 25 000, Blatt Nr. 5638 Bobenneukirchen. - 60 pp, München. GIEBEL, C.G. (1852): Fauna der Vorwelt mit steter Berücksichtigung der lebenden Thiere, Bd. 3, Mollusken, Abteilung 1, Cephalopoden. - 856 pp, Leipzig.

GORTANI, M. (1907): Contribuzioni allo studio del Paleozoico Carnico III. La fauna a climenie del Monte Primosio. - Mem. R. Acad. Sei. Inst. Bol., ser. 6, 4: 201-243. GUPTA, V.J. & ERBEN, H.K. (1983): A Late Devonian ammonoid faunule from Himachal Pradesh. - Paläont. Z., 57 (1-2): 93-102. HERITSCH, F. (1943): Das Paläozoikum. - In: HERITSCH, F. & KÜHN, 0.: Die Stratigraphie der geologischen Formationen der Ostalpen. Bd. 1,681 pp, Berlin. HÖLDER, H. (1973): Miscellanea cephalopodica. - Münst. Forsch. Geol. Pal., 29: 39-76. HOLLARD, H. (1956): Sur le Tournaisien de la vallee du Dra (Sud marocain). - C. R. Acad. Sei., Paris, 242: 2752-2755. (1958): Decouverte de Goniatites tournaisiennes dans le Ma'ider (Province de Tafilalet, Maroc). - C. R. Acad. Sei, Paris, 247 (10): 789-792. (1960): Une phase tectonique intrafamenniense dans le Tafilalt et le Ma'ider (Maroc presaharien). - C. R. Acad. Sei., Paris, 250: 1303-1305. - (1970): Sur la Transgression Dinantienne au Maroc Presaharien. - C. R. 6e Congr. Intern. Strat. Geol. Carbonif., Sheffield 1967, Vol.111: 923-936. - & JACQUEMONT, P. (1956): Le Gothlandien, te Devonien et le Carbonifere des regions du Dra et du Zemoul. - Notes Serv. Geol. Maroc, 15 (135): 7-33. HORSTIG, G. & STETTNER, G. (1976): Geologische Karte von Bayern, Erläuterungen zu Blatt Nr. 5735 Schwarzenbach am Wald, mit Beiträgen von K. BACHER, K. BERGER, und G. RÜCKERT. - München. HOUSE, M.R. (1963): Evolution observed. Discovery, 29 (9): 12-17. - (1965): A study in the Tornoceratidae: the succession of Tornoceras and related genera in the North American Devonian. Phil. Trans. R. Soc. Lond., B, 250: 79-130. - (1970): On the origin of clymenid ammonoids. Palaeontology, 13 (4): 664-676. - (1981 ): On the Origin, Classification and Evolution of the Early Ammonoidea. - Syst. Assoc. Spec. Vol., 18: 3-36. - (1985): Correlation of mid-Paleozoic ammonoid evolutionary events with global sedimentary perturbations. - Nature, 313: 17-22. - (1993): Fluctuations in ammonoid evolution and possible environmental controls. - Syst. Assoc. Spec. Vol., 47: 13-34. - & PRICE, J.D. (1985): New late Devonian genera and species of tornoceratid

Taxonomy and Evolution of Tornocerataceae (Ammonoidea)

goniatites. - Palaeontology, 28 (1 ): 159188. HOUSE, M.R., KIRCHGASSER, W.T., PRICE, J.D. & WADE, G. (1985): Goniatites from Frasnian {Upper Devonian) and adjacent strata of the Montagne Noire. - Hercynica, 1 (1 ): 1-21 . HYATI, A. (1884): Genera of fossil cephalopods. - Proc. Boston Soc. Natur. Hist., 22: 253338. JACOBS, D.K. & LANDMAN, N.H. (1993): Nautilus- a poor model for the function and behaviour of ammonoids? - Lethaia, 26: 101-111 . JUX, U. & KRATH, J. (1974): Die Fauna aus dem mittleren Oberdevon (Nehden-Stufe) des südwestlichen Bergischen Landes (Rheinisches Schiefergebirge). - Palaeontogr., Abt. A, 147: 115-168. KEUPP, H. & ILG, A. (1992): Paläopathologie der Ammonitenfauna aus dem Obercallovium der Normandie und ihre palökologische Interpretation. - Berl. geowiss. Abh., E, 3: 171-189. KORN, D. (1981): Ein neues Ammonoideenführendes Profil an der Devon-CarbonGrenze im Sauerland (Rhein. Schiefergebirge). - N. Jb. Geol. Paläont., Mh., 1981 (9): 513-526. - & LUPPOLD, F.W. (1987): Nach Clymenien und Conodonten gegliederte Profile des oberen Famenniums im Rheinischen Schiefergebirge. - Cour. Forsch.-lnst. Senckenberg, 92: 199-223. KULLMANN, J. (1960): Die Ammonoidea des Devon im Kantabrischen Gebirge (Nordspanien). - Akad. Wiss. Lit. Mainz, Abh. math.-naturwiss. KI., 1960 (7): 105 pp. LANGE, W. (1929): Zur Kenntnis des Oberdevons am Enkeberg und bei Balve (Sauerland). - Abh. Preuß. Geol. L.-A., N.F., 119, 132 pp. LEWOWICKI, S. (1959): Fauna wap1ern klimeniowych z dzikowca klodzkiego. - Biul. Inst. Geol., 146: 72-112. MAKOWSKI, H. (1991) : Dimorphism and evolution of the goniatite Tornoceras in the Famennian of the Holy Cros Mountains. Acta Palaeont. Pol., 36 (3): 241-254. N. (1930): Recherches ,MENCHIKOFF. geologiques dans le Nord du Sahara occidental. - Rev. Geogr. phys. Geol. dyn., 8 (2), 144 pp. MILLER, A.K. & FURNISH, W.M. (1957): Paleozoic Ammonoidea (Anarcestina, Goniatitina, Prolecanitina). - in: Treatise on lnvertebrate Paleontology, Part L, Mollusca 4, Cephalopoda, Ammonoidea (ed. R.C. MOORE): 11-36, 47-49, Kansas Univ. Press.

635

MÜLLER, K.J. (1956): Cephalopodenfauna und Stratigraphie des Oberdevons von Schleiz und Zeulenroda in Thüringen. - Geol. Jb., Beih., 20, 93 pp. MÜNSTER, G. (1832): Über die1 Planuliten und Überga1ngs-Kalk des Goniatiten im Fichtelgebirges. - 38 p., Bayreuth. - (1839): Nachtrag zu den Goniatiten des Fichtelgebirges. - Beitr. Petrefactenkd., 1: 16-31. Die Versteinerungen des (1840): Übergangskalkes mit Clymenien und Orthoceraten von Oberfranken. - Beitr. Petrefactenkd., 3: 33-121. NALIVKINA, A.K. (1936): 0 verkhnedevonskiye Goniatitovye sloi reki Ai (Yuzhnyi Ural). Trudy Tsentr. Nauchno-lssledov. skogo Geol.-Razved. Inst., 79: 1-~~4. - (1953): Verkhnedevonski goniatity i klimeni Mugodzhar. - Trudy vses. nett. nauchnoissled. geol.-razv. Inst., Nov. Ser., 72: 60125. PAECKELMANN, W. (1936): Geiologische Karte von Preußen 1 : 25 000, Blatt Madfeld und Erläuterungen, Lieferung 341 . - 79 pp, Berlin. - (1938): Geologische Karte vcin Preußen und benachbarten Ländern, Lieferung 349. Erläuterungen zu Blatt Balve, Nr. 2655. 69 pp, Berlin. PETIER, G. (1951): Devonien moyen et superieur de la Saoura et du environs d'Ougarta (Sahara occidental) . - Bull. Soc. Geol. Fr., 6e ser., 1: 351-3ß2. - (1952): Le Devonien moyen et superieur. - 19th Intern. Geol. Congr., Monogr. reg., 1e ser., 15: 62-74. - (1954): Famennien terminal aux environs de Beni-Abbes (Sahara Nord-Occidental). Bull. Soc. Geol. Fr., 6e ser., 4: 11-16. - (1959): Goniatites Devonienrn:~s du Sahara. Pub!. Serv. Garte geol. Alger., N. S. , Paleont. Mem., 2: 313 pp. PFEIFFER, H. (1954): Der Bohlen bei Saalfeld. Geologie, Beih., 8: 105 pp. RAYMOND, P.E. (1909): The fauna of the Upper Devonian in Montana. - Ann. Carnegie Mus., 5: 141-158. RICHTER, R. (1848): Beitrag ziur Paläontologie des Thüringer Waldes: Die1Grauwacke des Bohlens und des Pfaffenberges bei Saalfeld. 1. Fauna. - 4H pp, Dresden, Leipzig. RICHTER, R. (1864): Clymenien und Goniatiten des Fichtelgebirges. - N. Jt>. Min. Geol., 32: 612-615. - & UNGER, F. (1856): Beitrag 2:ur Paläontologie des Thüringer Waldes. - Denkschr. kön.

636

BECKER, R.Th.

Akad. Wiss., math.-naturwiss. Cl., Wien, 11: 87-186. RUAN, Y .-P. (1978): The zonation of Devonian ammonoids in China. - Acta Strat. Sin., 3 (2): 143-137. - (1981 ): Devonian and earliest Carboniferous ammonoids from Guangxi and Guizhou. Mem. Nanj. Inst. Geol. Pal., Acad. Sin., 15 (7), 1-151. - (1991 ): On relationship between ammonoid of distribution and development syndepositional taphrogenesis during Late Paleozoic and Triassic in China. - In: Palaeoecology of China, Vol. 1 (JIN, Y., WANG, J. & XU, S., Eds.): 85-131, Nanjing (Nanjing University Press). SAUNDERS, W.B. & SWAN, R.H. (1984): Morphology and morphologic diversity of Mid-Carboniferous (Namurian) ammonoids in time and space. - Paleobiology, 10 (2): 195-228. SCHINDEWOLF, O .H. (1921): Versuch einer Paläogeographie des europäischen Oberdevonmeeres. - Z. dt. geol. Ges., 73:

137-223. (1923): Beiträge zur Kenntnis des Palaeozoikums in Oberfranken, Ostthüringen und dem Sächsischen Vogtlande. 1. Stratigraphie und Ammoneenfauna des Oberdevons von Hof a. d. Saale. - N. Jb. Min. Geol. Pal., Beil.-Bd., 6 (3/4): 250-357,

393-509. -

(1924): Bemerkungen zur Stratigraphie und Ammoneenfauna des Saalfelder Oberdevons. - Senckenbergiana, 8: 63-96. - (1936): Neue Gattungen tiefoberdevonischer Goniatiten. - Z . dt. geol. Ges., 88: 689-691. - (1937): Zur Stratigraphie und Paläontologie der Wocklumer Schichten (Oberdevon). - Abh. Preuß. Geol. L.-A., N. F., 178, 132 pp. (1944): Grundlagen und Methoden der paläontologischen Chronologie. - 139 pp., Berlin. - (1950): Grundfragen der Paläontologie. - 5i36 pp, Stuttgart (Schweizerbart). - (1952): Über das Oberdevon und Unterkarbon von Saalfeld in Ostthüringen. Eine zur Stratigraphie und Nachlese Ammoneen-Fauna. - Senck., 32 (5/6): 281306. SCHMIDT, H. (1922): Das Oberdevon-CulmGebiet von Warstein i. W. und Belecke. Jb. Preuß. Geol. L.A., 41 (1): 254-339. (1923): Neubestimmung der Gonioclymenienfauna von Saalfeld. - Senck., 5 (1/2): 56-59. - (1924): Zwei Cephalopodenfaunen an der Devon-Carbongrenze im Sauerland. - Jb. Preuß. Geol. L.-A., 44: 98-171.

SIMAKOV, K.V., BOGOSLOVSKIY, B.I., GAGIEV, M.K., KONONOVA, L.I., KOCHETKOVA, N.M., KUSINA, L.F., KULAGINA, E.I., ONOPRIENKO, U.I., PAZUKHIN, V.N., RADINOVA, E.P., RASINA, T.P., REITLINGER, E.A., SIMAKOVA, L.V. & YANOULATOVA, M.G. (1983): Biostratigrafiya pogranichnikh otloszheny Devona i Karbona. Kharakteristikye pogranichnikh otloszheniy Devona i Karbona Mugodzhar. - Akad. Nauk. Magadan, 51 pp. SOBOLEV, D.N. (1911): L'etage famennien de la chaine de montagnes de KielceSandomierz. - Ezegodnik po geologii i mineralogii Rossii, 13: 34-41. - (1912a): O verkhnem neodevone okrestnostei Kelets. - lzv. Warsh. Politekh. Inst., 2: 3441. - (1912b): 0 verkhnem neodevone Lagowa. · lzv. Warsh. Politekh. Inst., 3: 1-20. - (1914): Skizzen zur Phylogenie der Goniatiten. - 195 PP, Warszawa [in Russ.]. SOWERBY, J. (1814): Mineral conchology of Great Britain, 1: 1-234, London. STASCHEN, D. (1968): Zur Geologie des Warsteiner und Be lecker Sattels (Rheinisches Schiefergebirge, Deutschland). - Münst. Forsch. Geol. Pal., 5, 119 pp. STEPANOVA, G.A., KHALYMBADZHA, V.G., CHERNYSHEVA, N.G., PETROVA, L.G. & POSTOYALKO, M.V. (1985): Boundaries of Stages of the Upper Devonian on the South Urals (The Eastern Slope) . - Cour. Forsch.-lnst. Senckenberg, 75: 123-134. SUN, Y-c & SHEN, Y.-t. (1965): On the late Upper Devonian fauna of the Wock/umeria beds of South Kweichow and its stratigraphical significance. - Prof. Pap. Acad. Geol. Sei., Min. Geol. Beijing, 1965, 1: 33-108. TALENT, J.A., GOEL, R.K., JAIN, A.K. & PICKETT, J.W. (1988): Silurian and Devonian of lndia, Nepal and Bhutan: Biostratigraphie and Palaeobiogeographic Anomalies. - Cour. Forsch.-lnst. Senck., 106, 57 pp. TERMIER, H. (1936): Etudes geologiques sur le Maroc central et le Moyen-Atlas septentrional, Tome HV. - Notes Mem. Serv. Mines Garte Geol. Maroc, 1566 pp. & TERMIER, G. (1950): Paleontologie Marocains. II. lnvertebres de l'Ere primaire. Fase. III, Mollusques. - Serv. geol. Prot. Franc. Maroc, Notes et Mem., 78,246 pp. TIETZE, E. (1871): Ueber die devonischen Schichten von Ebersdorf unweit Neurode in

Taxonomy and Evolution of Tornocerataceae (Ammonoidea)

der Grafschaft Glatz. - Palaeontogr., 19: 103-158. TRUEMAN, A.E. (1941): The ammonite body chamber, with special reference to the buoyancy and mode of life of the living ammonite. - Quart. J. Geol. Soc. London, 96: 339-383. WEDEKIND, R. (1908): Die Cephalopodenfauna des höheren Oberdevon am Enkenberg. N. Jb. Min. Geol. Pal. , Beil.-Bd., 26: 565635. - (1910): Posttornoceras balvei n.gen. n.sp. - Ein neuer Fall von Konvergenz bei Goniatiten. - Cbl. Min. Geol. Pal., 1910: 768-771. - (1918): Die Genera der Palaeoammonoidea (Goniatiten). - Palaeontogr., 62: 85-184. WENDT, J. (1988): Condensed carbonate sedimentation in the late Devonian of the eastern Anti-Atlas (Morocco). - Eclogae Geol. Helv., 81: 155-173. - (1989): Facies pattern and Paleogeography of the Middle and Late Devonian in the eastern Anti-Atlas (Morocco). - Can. Soc. Petr. Geol., Mem., 14, 1: 467-480. - , AIGNER, T. & NEUGEBAUER, J. (1984): Cephalopod limestone deposition on a shallow pelagic ridge: the Tafilalt Platform

637

(Upper Devonian, eastern Anti-Atlas, Morocco). - Sedimentology, 31: 601 -625. WEYER, D. (1981): Glatziella RENZ 1914 (Ammonoidea, Clymeniida) im Oberdevon von Thüringen. - Hall. Jb. f. Geowiss., 6: 112. WURM, A. (1927): Erläuterungen zur Geologischen Karte von Bayern, 1 : 25 000, Blatt Presseck, Nr. 52, mit einem bodenkundlichen Beitrag von Dr. U. SPRINGER. - 67 pp, München. - (1961 ): Geologie von Bayern. 1. Frankenwald, Münchberger Gneismasse, Fichtelgebirge, Nördlicher Oberpfälzer Wald. - 554 pp., Berlin. - (1962): Sammlung Geologischer Führer, Bd. 41: Frankenwald, Fichtelgebirge und Nördlicher Oberpfälzer Wald. - 184 pp., Berlin (2nd edition, Bornträger). YUAN, J. (1988): Proetiden aus dem jüngeren Oberdevon von Süd-China. - Palaeontogr., Abt. A, 201 (1-3): 1-102. ZIMMERMANN, E. (1914): Erläuterungen zur Geologischen Karte von Preußen und benachbarten Bundesstaaten, Lieferung 40, Blatt Saalfeld a. Saale. - 130 pp., Berlin (2nd edition).

638

BECKER,

R.Th.

Plate 1: Planitornoceras n.gen. and related forms from Germany and North Africa Planitornoceras pugnax n.gen. n.sp. The holotype, Be 1341, Rich Bou Kourazia, x 3. 1. Lateral view showing a shallow mid-flank depression, typical sutures and probable trecking bands. 2. Adoral view; at maturiry the venter becomes slightly bicarinate. Planitornoceras cf. transuralense (NALIVKINA) Specimen from Enkeberg, MNHU, x 1.5. 3. Lateral view showing growth ornament and a very weak, spiral, mid-flank depression. 4. Ventral view with well-preserved ventral band and shallow median groove. Loose specimen from above the Annulata Event beds at Ettenberg, Be 1326, x 1.5. 5. Lateral view with ornament and shallow spiral depression. 6. Ventral view showing sharp ventral edges. Planitornoceras euryomphalum (WEDEKIND) The lectotype, Enkeberg, GPIG 389-32, Original of WEDEKIND (1918), x 1.5. 7. Lateral view showing growth lines. 8. Adoral view; at maturity the venter becomes bicarinate. Small specimen from Jebel Merakeb, Be 1342, x 3. 9. Lateral view with sutures and typical ventrolateral salient of ornament impressed on the internal mould. 10. Ventral view; external side flatly rounded. Planitornoceras n.sp. aff. transuralense (NALIVKINA) Be 585, typical specimen from the Nie Brickwork Quarry, Bed 7-9 (Prolobites delphinus Zone), x 1.4. 11. Lateral view with prominent, spiral, mid-flank depression. 12. Ventral view; cross-section extremely compressed, venter tabulate and not becoming bicarinate) Planitornoceras cf. euryomphalum (WEDEKIND) Interna! mould from the Saoura Valley, Southern Algeria, MNHP. 13. Lateral view with impressed ornament and sutures, x 2. 14. Ventral view showing ventral edges, x 2.25. Gen. nov. aff. Planitornoceras sp. Specimen from the Saoura Valley, Southern Algeria, MNHP, x 2. 15. Lateral view showing the unusual wide and high dorsolateral salient of growth lines. 16. Eroded ventral view; originally the venter was tabulate.

640

BECKER, R.Th.

Plate 2:

Polonoceras subundulatum (FRECH) Be 769/1, juvenile specimen from Nehden-Schurbusch, x 3. 1. Lateral view illustrating the strongly projecting ventrolateral growth line salient (in comparison to Planitornoceras n.gen). Pernoceras crebriseptum (RAYMOND) Be 1343/1, juvenile topotype from the Three Fork Shale, Montana, x 4.5. 2. Lateral view showing the open umbilicus and sutures. 3. Adoral view showing the septal face and rounded whorl form. ? Exotornoceras sylviae n.sp. Holotype, Be 1333, Taourart, x 3. 4. Lateral view with sutures. 5. Adoral view; cross-section compressed but well-rounded. Paratype, MNHP ds 8318-1, Fezzou, x 3. 6. Lateral view. 7. Ventral view. Paratype, Be 1334, Taourart, x 3. 8. Lateral view showing the ontogenetic subdivision of the subumbilical saddle. 9. Adoral view with septal face.

Exotornoceras fezzouense n.sp. Holotype, Be 1331, Fezzou area, Maider (purchased specimen), x 1.5. 10. Lateral view with sutues. 11. Adoral view showing compressed cross-section. Paratype, Eb-C7, Jebel Aguelmous, NE of Fezzou, x 3. 12. Lateral view showing steep umbilical wall. 13. Adoral view. Gundolficeras delepinei (PETTER) The neotype, MNHP ds 8318-2, Fezzou, x 3. 14. Septate lateral view. 15. Adoral view; cross-section inflated and tegoid. Gundolficeras bicanicu/atum (PETTER) The neotype, Be 1328, Jebel Aguelmous, NE of Fezzou, x 3. 16. Lateral view illustrating the deep, open umbilicus and sutures. 17. Adoral view showing the septal face and inflated, well-rounded whorl form. Juvenile specimen from Fezzou, MNHP ds 8318-5. 18. Lateral view with sutures; ventrolateral furrowweaken on the body chamber, x 4. 19. Adoral view with typical ly rounded whorl form, x 3. Questionable juvenile, Eb-C3, Jebel Aguelmous, NE of Fezzou, x 3. 20. Lateral view. 21. Adoral view illustrating the well-developed, narrow, ventrolateral, spiral grooves. Falcitornoceras falcatum (FRECH) Be 1038, Nehden-Schurbusch, x 4.5. 22. Lateral view with characteristic falcate ribbing (in contrast to Fig. 18 and 20). 23. Adoral view.

Gundolficeras escoti (FRECH) The lectotype, La Serre, "Supragriotte", MNHU, x 1.5. 24. Lateral view. 25. Adoral view. Type of Tornoceras Escoti var. carnicum GORTANI (Photo courtesy by M.R. HOUSE), Monte Primosio, Carnic Alps, x 2. 26. Lateral view showing the outer suture. 27. Ventral view.

642

BECKER, R.Th.

Plate 3

Posttornoceras aff. contiguum (MÜNSTER) Eb-C2, Jebel Merakeb, x 3. 1. Septate lateral view. 2. Adoral view.

Discoclymenia cucullata (v. BUCH) Be 1338/4, Jebel Aguelmous, NE of Fezzou, meadian-sized specimen, x 3. 3. Lateral view with fine, strongly biconvex growth lines and ventrolateral furrows in the apical part. 4. Adoral view with typical septal face and weak ventrolateral furrows. Ü164/10, FU Berlin Teaching Collection, Fezzou, mature specimen, x 1.1. 5. Lateral view 6. Adoral view with septal face. Be 1338/2, Jebel Aguelmous, NE of Fezzou, median-sized specimen, x 3. 7. Lateral view showing undulose falcate ribbing on the apical whorl half. Afpinites kayseri (SCHINDEWOLF) Eb-C1, well-preserved haematitic mould from Taourart, x 1.1. 8. Septate lateral view. 9. Adoral view showing the little ridge seperating the dorsal and outer L1-lobes on the septal face. 10. Oxyconic ventral view. 11. Adoral view in different light illustrating the horizontal links between opposite flank lobes and saddles on the septal face.

Sporadocer§ls posthumum WEDEKIND Original (no syntype) of MÜNSTER, det. Goniatites contiguus, MNHU, Schübelhammer, x 1.5. 12. Lateral view with sutures which are homoemorphic to those in Post. contiguum. 13. Adoral view; cross-section rather wide; parts of the septum preserved. Sporadoceras clarkei WEDEKIND Lectotype (designated herewith), GPIG 390-23, original of WEDEKIND (1908): PI. 42, Fig. 4, Enkeberg, 1.1. 15. Lateral view showing the low aperture and slowly expanding whorls unlike in any Posttornoceratidae. 16. Adoral view.

X

Sporadoceras varicatum WEDEKIND Lectotype (designated herewith), GPIG 390-25, original of WEDEKIND (1908): PI. 42, Fig. 6, Enkeberg, x 1.1. 17. Lateral view with typical con strictions which are lacking in all known Posttornoceratidae. 18. Adoral view.