Santi et al.indd - CiteSeerX

Revue de Paléobiologie, Genève (décembre 2005) 24 (2) : 597-616

ISSN 1661-5468

Morphometry of the limb bones of the Ursus spelaeus ROSENMÜLLER, 1794 from Valstrona (Piedmont-Northern Italy) Giuseppe SANTI1*, Mario ROSSI2 & Alessandro FONTE1 Abstract A morphological and morphometrical study on Ursus spelaeus ROSENMÜLLER, 1794 limb bone remains from the Delle Streghe Cave (Sambughetto Valstrona, Piedmont Region, North Italy) is presented. Some of the fossils were affected by pathologies (periarthritis and pseudoarthrosis) and by traces of predatory activities. In several cases correspondence between meaningful parameters have permitted sexual differentiation and the singling out of at least two populations of different body size and probably different chronologies. They are compared to bears from both the Grotta Sopra Fontana Marella (Varese, Lombardy), and the Buco dellʼOrso Cave (Laglio, Lombardy). Key words Limb bones, Ursus, population, morphometry, Valstrona, Northern Italy. Résumé Morphométrie des os des pattes de lʼUrsus spelaeus ROSENMÜLLER, 1794 de la Grotte Delle Streghe (Sambughetto Valstrona, Piémont-Italie du Nord).- Les fossiles des os des pattes de lʼUrsus spelaeus ROSENMÜLLER, 1794 de la Grotte Delle Streghe (Sambughetto Valstrona, région Piémont, Italie du Nord) sont ici étudiés morphologiquement et morphométriquement. Chaque fossile présente des pathologies (periarthrites et pseudoarthroses) et des traces de prédation. Dans beaucoup de cas des relations entre des paramètres significatifs ont permis une distinction sexuelle et lʼindividualisation dʼau moins deux populations de taille différente et probablement, une chronologie différente. Ils sont comparés soit avec les ours de la Grotta Sopra Fontana Marella (Varese, Lombardie), soit, pour une partie, avec ceux de la Grotte du Buco dellʼOrso (Laglio, Lombardie). Mots-clés Os des pattes, Ursus, population, morphométrie, Valstrona, Italie du Nord.

I. INTRODUCTION

II. PREVIOUS WORKS

There are no doubts that Ursus spelaeus ROSENMÜLLER, 1794 should be considered a fundamental element in the rich Pleistocene biodiversity of the Alps and Prealps. It has been an object of study for a long time. Naturally, the large amount of fossils represents good material for analysis despite the fact that a number of sites have not been properly examined. Recently, this gap has partially been filled in regard to some caves in the Lombardy and Veneto Regions (Buco dellʼOrso Cave, Cerè Cave, Velo Cave) (SANTI & ROSSI, 2001a, b ; ROSSI & SANTI, 2001, 2002). In this article some morphometric considerations about the numerous limb bone remains of bears from the Delle Streghe Cave (Sambughetto Valstrona, Piedmont Region, Northern Italy) will be presented furthering knowledge of the Italian Ursus spelaeus, hitherto only partially studied by VENZO (1954) (Fig. 1).

Studies on U. spelaeus fossils are quite common but they frequently involve cranial and mandibular remains. Attention to the postcranial bones is less frequent. Hence the literature on the topic is scarce. DUBOIS & STEHLIN (1933) and KOBY & FRITZ (1950) analysed metatarsal and phalangeal remains. By studying different fossils KOBY (1950) was later able to re-construct an anterior, almost a complete paw (with only one missing uncinate), and compare it with todayʼs brown bear. Many studies having as focal point the bones of the locomotor apparatus of the bears, analyse their sexual dimorphism (i.e. KURTÉN, 1955). In this regard CUGGIANIʼs (1981) analysis is worthy of note. This author carried out a biometrical analysis of the long bones of the Würmian population of the U. spelaeus from the Equi Cave (Tuscany Region) noting great sexual dimorphism for the humerus and femur (the proximal and distal epiphyses

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Dipartimento di Scienze della Terra, Via Ferrata 1, I-27100 Pavia, Italy. *E-mail : [email protected] (corresponding author) Museo Civico di Storia Naturale, Lungadige Porta Vittoria 9, I-37127 Verona, Italy

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G. SANTI, M. ROSSI & A. FONTE

Fig. 1 : Geographic position of the Delle Streghe Cave (Piedmont Region, N. Italy).

of males have a larger transversal diameter than the females), but less divergence for the radii and ulnae. More recently, other significant studies were undertaken by RABEDER (1991), KUNST (1992, 1996), GRANDAL DʼANGLADE (1993), RUSTICHELLI (1993) and in particular by REISINGER & HOHENEGGER (1998). TORRES (1988) undertook the most detailed research on these parts of bear anatomy. He observed sexual dimorphism by comparing U. spelaeus, U. deningeri and U. arctos. Generally sexual dimorphism was more prominent in the long bones (humeri, ulnae, radii, femurs and tibiae), but much less so in the carpals, metacarpals and phalanges. KUNST (1992) compared biometrical analyses done on femurs of European Pleistocenic bears. This author found that the bone structure originally derived from the need for stability. More recently WEINSTOCK (1999) described the bear locomotor apparatus bones found among material gathered from the Grosse Grotte (Blauberen SW Germany) and compared their morphodimensional attributes with fossils from other German caves. He concluded that most remains had dimensions

correlating with younger bears. He also followed a sexual differentiation hypothesis. Using a mathematical base VIRANTA (1994) suggested that some correlations existed between the proportions of limbs and their mass in cave and present day bears. The shafts are wider in the cave bearsʼ limbs and consequently, their body mass appears to have been greater. In their morpho-dimensional analysis of remains from Arcy-sur-Cure (Yonne, French) BARYSHNIKOV & DAVID (2000) confronted the problem of establishing a reliable classification for small sized fossils. DI CANZIO & PETRONIO (2001) studied carpal, metacarpal, tarsal and metatarsal remains, probably from a female bear, from the Cola Cave (Aquila Abruzzo Region). More recently, a preliminarily study by ROSSI & SANTI (2001) presented a biometrical analysis of the long bones of the Ursus from the Buco dellʼOrso Cave (Laglio Como Province, N of Milan), while GERHARD (2001) proposed undertaking more detailed study of the Ursus metapodial bones from Austrian caves and formulated an evolutionary hypothesis to explain their characteristics. Other research was also carried out by GERMONPRÉ & SABLIN (2001) on

Morphometry of the limb bones of the Ursus spelaeus from Valstrona

fossils from Goyet (Belgium), by SANTI et al. (2003) on metapodial remains from the Buco dellʼOrso Cave, and by JAMBREŠIĆ & PAUNOVIĆ (2002) who presented the results of their acute osteometrical, biomechanical and locomotion analyses on Ursus limb remains from Croatian caves. Lastly PEREGO et al. (2001) extensively studied a great amount of U. spelaeus bones from Campo dei Fiori Massif (Varese NW of Milan) suggesting new interesting biometrical correlations between Ursus limbs from different age and TSOUKALA et al. (2001) for the Loutraki area (Pella, Macedonia, Greece). III. BRIEF GEOGRAPHIC AND GEOLOGICAL PICTURE The Valstrona (Fig. 1) is a narrow valley ; its lower part has a V shape with its head pointing towards Cima di Capezzone-Punta del Pizzo (2240 m)-Punta dʼIssola (2146 m) where it opens out to become a wide circle. It extends for 20 km till it reaches the village of Omegna where it merges into the larger Orta Lake valley (Cusio village). Many caves can be found in the so called “Marmo Valstrona” rocks near Sambughetto village. This is a unit enclosed between the gneiss and micaschists of the so called “Serie Kinzigitico-sillimanitica”. Inside the caves the osteological material, accompanied by yellow loessic clay, is collected in the lower parts along the side lanes and cavities. This sediment is frequently covered by hard stalagmitic soil (about 15-20 cm thick), and by grey micaceous and sterile sands interspersed with smaller gravel of more recent age linked to the pluvial washing away phase. To ensure the bones were maintained in a good state of preservation, the deposit was only slightly rearranged and analysed in situ. The fossils studied were found in caves known as ʻComplesso dellʼIntaglioʼ and ʻCaverna Delle Stregheʼ located near the Cava Sambughetto village. The former opens out in proximity to the upper part of the marble quarry (“Sass Muiè”) and it presents five entries, a complex of small subcircular galleries correlated to an ancient water-bearing level. The second and wider cave in the Verbania Province, is the so-called Caverna Delle Streghe. It is composed of a fossil branch today foliated by water, and by a second active branch sculpted by the river in the marble (Fig. 2). The water comes from the Chignolo stream that, after to having crossed the cave and taken in water from other tributaries, re-emerges in the Strona River. IV. MATERIALS AND METHODS This work presents a study of about 600 specimens of Ursus stored in the Museo Civico of Storia Naturale of

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Milan and labelled as Museo Storia Naturale Milano (MSNM) followed by a “V” and a progressive number. Their state of preservation is generally good, but some remains are incomplete or have been subjected to varying degrees of erosion especially in their proximal and distal extremities. In addition, some specimens showing pathologies mostly linked to periarthritis and pseudoarthrosis, or bearing traces of predatory activities, were also analysed (Fig. 3). This latter aspect was confirmed by the presence of felines among the Delle Streghe fauna. A proximal epiphysis (MSNM V 4329) linked to the first half of the diaphysis of a right radius of Panthera leo spelaea (GOLDFUSS, 1810) has also been discovered (Fig. 4). Osteometrical measures were effected utilising the HUE (1907), VON DEN DRIESCH (1976) and TORRES (1988) schemas. The fossils are nearly whole and have been attributed to Ursus spelaeus ROSENMÜLLER, 1794. Although the typical morphological characteristics of this species are very well defined, often their unclear identification prevents certain classification and suggests, in these cases, the possible presence of U. deningeri VON REICHENAU, 1904. We therefore classified these fossils as U. spelaeus according to a wider morphological categorisation for this species (Pl. I-V). V. DISCUSSION Morphometrical data was compared using diagrams that highlight the analogies and differences with other bears from Italian and foreign caves. Comparisons between significant metacarpi and metatarsi index of the Ursus from Italian and foreign caves, are shown in Fig. 5. Generally Delle Streghe Cave (DSC) fossils correlate well with spelaeus from the Buco dellʼOrso Cave (Laglio village, Lombardy Region, Northern Italy) and they are almost always smaller than those typical of Spanish caves. In some cases, the metacarpi and metatarsi sections are close to those of the U. deningeri, but this could also be due to presence of different sexes or different ages living together with the adult population (see below). The “plumpness index” diagram shows that the metapodial dimensions analysed are close to the Buco dellʼOrso fossils ; the latter being very similar to the ones from the foreign localities. Humerus : The ratio between the Antero-posterior diameter of the diaphysis and the Transversal diameter of the diaphysis in Ursus spelaeus populations (adults and juveniles) from the Sopra Fontana Marella Cave –GSFM (Campo dei Fiori, Varese, Lombardy) and from the Delle Streghe Cave, is shown in diagram Fig. 6. The Delle Streghe spelaeus point positions are distributed in a dispersion cloud that correlates well with the Sopra Fontana Marella Cave bears, which follow the same

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Fig. 2 : A. Planimetric schema of the Delle Streghe Cave. B. Profiles of the same cave (CELLA, 1993 mod.).


Fig. 3 : A - Pathological bones of Ursus. Specimen MSNM V 4362 (Delle Streghe Cave). B - Traces of predatory activities. Specimen MSNM V 4097 (Delle Streghe Cave).

Fig. 4 : Panthera leo spelaea (GOLDFUSS, 1810). Specimen MSNM V 4329 (Delle Streghe Cave). Right radius. A – External view, B – Internal view.

trends. The transversal diameter has the same values as the more recent spelaeus specimens from the GSFM, but the antero-posterior diameters (smaller for the Delle Streghe bears) present flatter humeri. Radius : By adopting the ratio between the Absolute Length and Transversal diameter of the distal epiphysis, the trends exhibited by the DSC bears are similar to

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the typical spelaeus ones from Spanish caves. The morphometrical data confirms the morphological evidence. Observations from the diagram in Fig. 7 comparing the ratios between the Antero-posterior diameter of the diaphysis and Transversal diameter of the diaphysis of bear populations from GSFM and DSC reveal the following : a) the representative points of the DSC bears are well within the dispersion cloud of the GSFM bears, b) a good number of specimens fall into the field zone containing adult elements from older and intermediate layers, juveniles are found in all levels from the oldest to the more recent, c) other fossils have similar sizes to the largest of the more recent specimens from GSFM. On the basis of this extremely fragmented distribution, two hypotheses can be put forward : a) we have both a male and female population, b) there are two different populations belonging to spelaeus bears of different sizes containing males and females that are related to Ursus according to different degrees of evolution (the more ancient with the smaller size, the more recent with a larger size) or linked to different climatic phases. Morphometric data from the radii should confirm humeri data. Ulna : The ratio between the Antero-posterior diameter of the diaphysis and the Transversal diameter of the diaphysis for the DSC and GSFM Ursus is indicated in Fig. 8. The trend observed for the DSC spelaeus fossils is well within the one defined by the bears used as reference. In this case too the fossil points are distributed inside the cloud drawn by the GSFM bears. The same considerations made of the radius can also be made for the ulnae. Pisiform : The diagram in Fig. 9 presents the significant ratio between the Greatest Length and Greatest Width. Ursus spelaeus (Buco dellʼOrso Cave –GBO and Spanish caves), U. deningeri and U. arctos also from the Spanish caves and bears from DSC, are compared. Three fields can be singled out : the representative points of the small size fall in the Spanish deningeri-arctos area and are similar to the Buco dellʼOrso ones. In this case, the spelaeus morphology of the fossils leads us to consider them as deningerian or arctoid forms. Therefore it would be logical to think of them as juvenile or female elements or, at the very least, as bears linked to cool climatic phases (GERHARD, 2001). The centre of the diagram is characterised (representing the greatest lengths) by adult specimens whose size is similar to the Buco dellʼOrso Cave bears, only wider and more robust. Lastly, the third area of the diagram represents those forms with a much larger size, albeit a flatter one. This feature could be explained if a clear distinction is drawn between the central field and the one typical of the larger sized bears. Alternatively, the reason may be low fossil numbers and consequently, lack of data linking the two fields. Another explanation may be that there are two well differentiated adult populations of different size. Hence, that the bears occupied different phylogenetic positions, or that they

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� Fig. 5 : Comparison between the meaningful index in the metacarpi and metatarsi of the different Ursus species. A - Proximal widthTotal length ratio in %. B – Smallest diaphyseal width-Total length ratio in %. C – “Plumpness index” (Distal epicondyleal width-Total length ratio in %).


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Fig. 6 : Distribution points of the Antero-posterior diameter of the diaphysis (ordinate) and Transversal diameter of the diaphysis (abscissa) relationship in the humeri of the Ursus spelaeus from Delle Streghe and Grotta Sopra Fontana Marella caves. Symbol legend : Delle Streghe specimens. Sopra Fontana Marella : juveniles from FM2, juveniles from FM1, juveniles from FM4, adults from FM2, Adults from FM1, Adults from FM4 and FM2 (PEREGO et al., 2001 mod.).

Fig. 8 : Distribution points of the Antero-posterior diameter of the diaphysis (ordinate) and Transversal diameter of the diaphysis (abscissa) relationship in the ulnae of the Ursus spelaeus from Delle Streghe and Grotta Sopra Fontana Marella caves. X Ursus cf. arctos. Asterisks indicate the Delle Streghe specimens, for the legend of the other symbols see Fig. 6 (PEREGO et al., 2001 mod.).

Fig. 7 : Distribution points of the Antero-posterior diameter of the diaphysis (ordinate) and Transversal diameter of the diaphysis (abscissa) relationship in the radii of the Ursus spelaeus from Delle Streghe and Grotta Sopra Fontana Marella caves. Asterisks represent the Delle Streghe specimens, for the legend of the other symbols see Fig. 6 (PEREGO et al., 2001 mod.).

Fig. 9 : Distribution points of the Greatest Length and Greatest Breadth ratio in the pisiforms of the different Ursus species from Italian and Spanish caves (SANTI et al., 2003 mod.).

were linked to different climatic phases as observed in the previous diagrams. Scapholunar : This data compared the Ursus spelaeus from Delle Fate Cave (Finale Ligure, Liguria Region [Fig. 10], Body Height-Maximum Length) and indicates that the Delle Streghe fossils show the same trends as the reference bears. Also in this case, morphometry confirms morphological observations. The dearth in literature of

presentations of other ratios between useful parameters not to mention comparisons with bears (deningeriarctos) from different localities, has here been somewhat rectified to enable further discussion. II Metacarpus : The data inserted in the diagram in Fig. 11, indicating the ratio between the Greatest Length and the Greatest breadth of the diaphysis, is limited. However, a comparison with the literature allows us to formulate some considerations : firstly, the Delle Streghe Cave fossils are well encompassed within the dispersion cloud of the

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Fig. 10 : Distribution points of the Body Heigth and the Greatest Length ratio in the scapholunars of the Ursus spelaeus from different Italian caves.

Fig. 11 : Distribution points of the Greatest length and the Smallest diaphyseal Width ratio in the II metacarpus of different Ursus species from Italian and Spanish caves (SANTI et al., 2003 mod.).

Buco dellʼOrso bears. Hence they indubitably represent the spelaeus elements having the greatest degree of conformity with what their morphology has highlighted. The arctos field can in fact be clearly distinguished from that of the cave bear. Secondly, the fossils are of a similar size to those from the Buco dellʼOrso bears and smaller than the typical spelaeus. Lastly, one point is located in a zone that occupies an inferior position compared to the point considered by DI CANZIO & PETRONIO (2001). This derives from a female and corresponds to those considered as females with cubs by SANTI et al. (2003). The hypothesis that this specimen is a female is wellgrounded. IV Metacarpus : The Smallest diaphyseal width and the Total Length ratio is observable in Fig. 12. This

Fig. 12 : Distribution points of the Smallest diaphyseal Width and the Greatest Length ratio in the IV metacarpus of the Ursus spelaeus from Italian and German caves (SANTI et al., 2003 mod.).

is a comparison with cave bears from Germany. In WEINSTOCKʼs (1999) opinion the representative points of the Grosse Grotte specimens are represented by females. The Delle Streghe bears show great variability, they are more robust and at least three remains have dimensions which are even smaller than the ones considered as coming from female bears. It is therefore logical to consider them as female, then to compare them to the Buco dellʼOrso cave bears. The other points located in the field of the bigger remains can be considered as coming from males. To conclude, this ratio can be useful in distinguishing between the sexes. V Metacarpus : Data relative to this part of the anatomy is scarce. Despite this, some considerations can be made. Diagram Fig. 13 shows the ratio between the Total Length and the Proximal width in different species of Ursus from Italian and Spanish caves. A first general observation is that the representative points of the Delle Streghe bears correspond to the trend defined regarding


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Fig. 14 : Distribution points of the Antero-posterior diameter of the diaphysis (ordinate) and Transversal diameter of the diaphysis (abscissa) ratio in the femurs of the Ursus spelaeus from Delle Streghe and Grotta Sopra Fontana Marella caves. Asterisks indicate the Delle Streghe specimens, for the legend of the other symbols see Fig. 6 (PEREGO et al., 2001 mod.). Fig. 13 : Distribution points of the Greatest Length and the Transversal diaphyseal Width ratio in the V metacarpus in the different Ursus species from Italian and Spanish caves.

the Buco dellʼOrso cave bears. Their dimensions are similar to the latterʼs and only slighly smaller than the typical spelaeus from Spanish caves. Three remains are clearly distinguishable, they are more robust and probably present a different trend compared to the one defined by other fossils. This can be explained as a dimorphic character or as coming from chronologically different populations. Femur : Fig. 14 highlights the relationship between the Transversal diameter and Antero-posterior diameter of the diaphysis. The specimens compared come from GSFM and GBO. Also in this case the Delle Streghe bears fall within the dispersion cloud created by the spelaeus fossils and follow the same trend. They are positioned in the upper range of distribution points. In this zone we see that some of the adult bears derive from either the older or the more recent layers in the GSFM like those from GBO. This would lead us to the conclusion that at least two populations of different sizes and chronology were present, as already seen for other parts of the anatomy. In the diagram there is also a point located in the lower part, well isolated inside an area where juvenile remains were found. Consequently, it is feasibile to consider this point as a juvenile element. Tibia : Similarly to what was indicated for the femur, the diagram in Fig. 15 compares the ratios between the Transversal diameter and the Antero-posterior diameter of the diaphysis for the tibiae because they are the parameter allowing the most detailed morphometrical analysis. In this case too, comparison between the GSFM and GBO populations leads to conclusions similar to those regarding the femur.

Fig. 15 : Distribution points of the Antero-posterior diameter of the diaphysis (ordinate) and Transversal diameter of the diaphysis (abscissa) ratio in the tibiae of the Ursus spelaeus from Delle Streghe and Grotta Sopra Fontana Marella caves. Asterisks denote the Delle Streghe specimens, for the legend of the other symbols see Fig. 6 (PEREGO et al., 2001 mod.).

Astragalus : The point dispersion was defined (Fig. 16) by using the ratio between the Greatest Length and Thickness, to compare astragali data coming from Delle Streghe, Buco dellʼOrso Caves and the Delle Fate Cave. The trends derived by the Delle Streghe bears follows those of Delle Fate and the Buco dellʼOrso remains, with the only exception being the slightly higher position occupied by the latter. Albeit of equal length, the astragali of the Buco dellʼOrso and Delle Streghe cave bears appear to be flatter, mainly in the former despite their paucity than among the latter. This evidence (flatter remains) had already been observed for other anatomical parts, therefore it should be a priori excluded that part of

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Fig. 17 : Distribution points of the Greatest Length and the Greatest Height ratio in the scaphoids of Ursus spelaeus from Italian caves.

the Delle Streghe population(s) could be characterised by flatter skeleton units than the ones from other localities. Heel and scaphoid : Akin to what was observed for the astragali, once again using the ratio between Total Length and Total Height (Fig. 17), the point distribution

of the scaphoids follows the Delle Fate cave bear trend. A similar situation is present in the heel distributions (Fig. 18). Unfortunately, the paucity of the remains impedes a precise enough analysis. III Metatarsus : The diagram in Fig. 19 presents the

Plate I Ursus spelaeus ROSENMÜLLER, 1794. Delle Streghe Cave (Sambughetto Valstrona). A – Radius specimen MSNM V 4331, external view, B – Radius specimen MSNM V 4304 dorsal view, C – Femur specimen MSNM V 4390, caudal view, D – Femur specimen MSNM V 4393, caudal view, E – Radius specimen MSNM V 4330 external view, F – metacarpus specimen MSNM V 4981, lateral view, G – metacarpus MSNM V 4981, medial view, H – metacarpus specimen MSNM V 4978, dorsal view, I – II phalanx specimen MSNM V 5006 palmar view, L – II phalanx specimen MSNM V 5015, dorsal view.

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Fig. 18 : Distribution points of the Greatest Height and the Greatest Breadth ratio in the heels of Ursus spelaeus from Italian caves.

Fig. 19 : Distribution points of the Smallest diaphyseal Width and the Greatest Length ratio in the III metatarsus of Ursus spelaeus from Italian and German caves (SANTI et al., 2003 mod.).

ratio between the Smallest width of the diaphysis and Total Length. Despite the scarcity of the remains, some considerations can still be formulated. In WEINSTOCKʼs (1999) opinion the Grosse Grotte fossil is a small male and the few representative points of the Delle Streghe bears fall into a category where the sizes are already the smallest. This trend is surely the typical of cave bears, and within the cloud dispersion both for the Sibyllenhöhle, and the Buco dellʼOrso fossils, but the small dimensions of these three specimens would suggest they were possibly females. The only point located on the right

Fig. 20 : Distribution points of the Greatest Length and the Smallest diaphyseal Width in the V metatarsus of different Ursus species from Italian and Spanish caves (SANTI et al., 2003 mod.).

side of the diagram can be considered more as a small male, but with a larger diaphysis, than a short specimen. This represents further confirmation that within the Delle Streghe population(s) some bears shorter in their anatomical parts, were present. V Metatarsus : The diagram in Fig. 20 shows the relationships between the Total Length and the Smallest

Plate II Ursus spelaeus ROSENMÜLLER, 1794. Delle Streghe Cave (Sambughetto Valstrona). A – Femur specimen MSNM V 4363, caudal view, B – Tibia specimen MSNM V 4422, caudal view, C – Tibia specimen MSNM V 4421, cranial view, D – Femur specimen MSNM V 4361, caudal view, E – Femur specimen MSNM V 4362 lateral view, F – I phalanx specimen MSNM V 4988, dorsal view, G – I phalanx specimen MSNM V 4987, palmar view, H – I phalanx specimen MSNM V 4992, palmar view, I – III phalanx specimen MSNM V 5028, lateral view.

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width of the diaphysis. Only two points have been inserted, and they are within the characteristics of a typical large sized spelaeus. Phalanx : The ratio between the Absolute Length and the Transversal diameter of the epiphysis of the I° phalanx is shown in the diagram in Fig. 21. A comparison with what is known from the literature (only specimens from Buco dellʼOrso Cave) allows us to verify only that this anatomical unit from the Delle Streghe Cave has dimensions that clearly correspond to the dispersion spectrum drawn from the data pertaining to the Buco dellʼOrso bears. Of significant interest is the reading of the diagram in Fig. 22 (Absolute Length-Diameter of the diaphysis ratio) regarding the II° phalanx. In this case too, the only referring population was the Buco dellʼOrso bears. But it should be clear how the two distribution fields, each enclosing a population, are defined. Buco dellʼOrso cave bears are of smaller size, and possible explanations are either lack of data, or the presence of subadult and/or female elements. Finally, in regard to the III° phalanx, from the little known data (U. deningeri, U. arctos, U. dolinensis, GARCIA & ARSUAGA, 2001, fig. 2) fossils from Delle Streghe Cave have sizes close to the deningeri ones but

showing a different trend both in comparison to the last, or to U. arctos, and U. dolinensis and in some cases, have proportions closer to the foot phalanges of the U. arctos. VI. CONCLUSIONS The abundant limb remains of Ursus spelaeus from Delle Streghe Cave (near Cava Sambughetto village) were studied morphologically and morphometrically. Further, a Panthera leo spelaea (GOLDFUSS, 1810) whose incomplete radius was discovered, confirm the biodiversity of this area clearly showing similarities with associations from other geographically close caves (Buco dellʼOrso Cave, DellʼOrso Cave, Delle Ossa Cave, Zandobbio, Bergamo Province, North of Milan). Morphometrical analysis leads us to believe that at least two cave bear populations of different sizes (considering only the adults) if not quite three, had moved. Those having smaller dimensions can be likened to the same sized ones from Buco dellʼOrso Cave and those from the older layers of the Grotta Sopra Fontana Marella. For example, this difference emerges clearly from the diagram describing the femurs or the tibiae not to mention the pisiform or the radii.

diameter transversal ephiphesis

25

20 15 10 B u c o d e ll'O r s o C a v e 5


0 0

10

20

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Fig. 21 : Distribution points of the Greatest Length and the Diameter transversal epiphesis ratio in the I phalanx of Ursus spelaeus from Italian caves.

Plate III Ursus spelaeus ROSENMÜLLER, 1794. Delle Streghe Cave (Sambughetto Valstrona). A – Pisiform specimen MSNM V 4804, medial view, B – Scaphoid specimen MSNM V 4916, distal view, C – Pyramidal specimen MSNM V 4798, distal view, D – Pyramidal specimen MSNM V 4797, distal view, E – Uncinate specimen MSNM V 4816, distal view, F – Cuboid specimen MSNM V 4924, distal view, G – Scapholunar specimen MSNM V 4781, lateral view, H – Scapholunar specimen MSNM V 4776, medial view.

Plate III

B

A

F C

D

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E

H

612


Diameter transversal diaphysis

18 16 14 12 10 8 6

B u c o d e ll'O r s o Ca v e

4

D e lle S tr e g h e C a v e

2 0 0

5

10

15

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Fig. 22 : Distribution points of the Greatest Length and the Diameter transversal diaphysis relationship in the II phalanx of Ursus spelaeus from Italian caves.

In PEREGO et al.ʼs (2001) opinion the difference in size is linked to the chronological position occupied by the bear ; smaller sized bears would be chronologically older and their increase in size linked to thermoregulation (BERGMANN, 1847). The increase in size is an advantage for thermoregulation. In bigger bodies heat losses are lower as they are linked to the surface-volume ratio (BOYCE, 1978). In this manner those breeds with large dimensions can colonize the cooler regions. This increase in size could represent a response to the shift towards a cooler climate. In contrast, RABEDER & NAGEL (2001) and GERHARD (2001) associate size reduction to a shift to cooler conditions. What we observed among the Delle Streghe remains is very similar to what has been concluded for the Grotta Sopra Fonta Marella populations : it is possible to link this trend to climatic variations. However, another possible reason for the increase in size can also be rapid evolution on the part of the cave bear. The radiometric and the amino acid racemization data of the bear bones from Grotta Sopra Fontana Marella have indicated the following ages : FM4 over 26000 years, FM2, 22310±200 and FM1, 21810±200 years (PEREGO et al., 2001). The remains studied almost always corresponded to the representative populations of the

three above mentioned layers with some parts being similar to those found in the Buco dellʼOrso Cave. ACKNOWLEDGEMENTS The Authors are indebted to Prof. M. GERMONPRÉ (Bruxelles) for his criticism and useful advice and to Dr G. PAPALIA (Pavia) for revision to English. This study was carried out with a grant from FAR. REFERENCES BARYSHNIKOV, G. & F. DAVID (2000) - Les ours des cavernes à Arcy-sur-Cure (Yonne, France). Ursus (spelearctos) spelaeus Rosenmüller et Heinroth, 1794. Quaternaire, 2 (1) : 65-79. BERGMANN, C. (1847) - Ueber die Verhaeltnisse der Waemeoekonomie der Thiere zu ihrer Grosse. Goettinger Studien, 3, Pt. 1 : 595-708. BOYCE, M.S. (1978) - Climatic variability and body size variation in Muskrats (Ondatra zibethicus) of North America. Oecologia, 36 : 1-19. CELLA, D. G. (1993) - Il patrimonio speleologico della Valstrona. Labirinti, 2-4.

Plate IV Ursus spelaeus ROSENMÜLLER, 1794. Delle Streghe Cave (Sambughetto Valstrona). A – Heel specimen MSNM V 4904, dorsal view, B – Astragalus specimen MSNM V 4874, dorsal view, C – II° metacarpus specimen MSNM V 4818, lateral view, D – III° metacarpus specimen MSNM V 4824, medial view, E – IV° metacarpus specimen MSNM V 827, medial view, F – IV° metacarpus specimen MSNM V 4828, medial view, G – V° metacarpus specimen MSNM V 4845, lateral view.

Plate IV

B

A

C

G

E F D

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CUGGIANI, M. C. (1981) - Studio biometrico sulle ossa lunghe della popolazione di Ursus spelaeus della grotta degli Equi (Toscana). Bollettino del Servizio Geologico, 102 : 173198. DI CANZIO, E. & C. PETRONIO (2001) - Osservazioni sulla fauna a vertebrati pleistocenici della Grotta Cola (Abruzzo, Aquila). Bollettino della Società Paleontologica Italiana, 40 (1) : 105-114. DUBOIS, A. & H. G. STEHLIN (1933) - La Grotte de Cotencher, station moustérienne. Mémoires de la Société Paléontologique Suisse, 53 : 177-292. GARCIA, N. & J. L. ARSUAGA (2001) - Ursus dolinensis : a new species of Early Pleistocene ursid from Trinchera Dolina, Atapuerca (Spain). Compte Rendu de lʼAcadémie des Sciences Paris, Sciences de la Terre et des Planètes, 332 : 717-725. GERMONPRÉ, M. & M.V. SABLIN (2001) - The cave bear (Ursus spelaeus) from Goyet, Belgium. Bulletin de lʼInstitut Royal des Sciences Naturelles de Belgique, Sciences de la Terre, 71 : 209- 233. GERHARD, W. (2001) - The evolution of metapodial bones in the cave bear group and its biostratigraphical implications. Cadernos Laboratorio Xeolòxico de Laxe Coruña, 26 : 365-371. GRANDAL DʼANGLADE, A. (1993) - El oso de las cavernas en Galicia : el yacimiento de Cova Eiròs. Serie Nova Terra 8, O castro, La Coruña : 285 pp. HUE, E. (1907) - Musée ostéologique. Étude de la faune quaternaire. Ostéométrie des Mammifères. 2 vol. Librairie C. Reinwold, Schleicher Frères Editeurs, Paris. JAMBREŠIĆ, G. & M. PAUNOVIĆ (2002) - Osteometry, variability, biomechanics and locomotion pattern of the cave bear limb bones from Croatian localities. Geologia Croatica, 55 (1) : 1-10. KOBY, F. (1950) - Les dimensions minima et maxima de os longs de Ursus spelaeus. Eclogae Geologicae Helvetiae, 43 (2) : 287. KOBY, F. & E. FRITZ (1950) - Les proportions des métacarpiens et des phalanges de la main dʼUrsus spelaeus. Eclogae Geologicae Helvetiae, 43 (2) : 288. KUNST, G.K. (1992) - Hoch-und spätglaziale Großsäugerreste aus dem Nixloch bei Losenstein-Ternenberg (O.Ö). In : NAGEL, D. & G. RABEDER (Eds). Das Nixloch bei Losenstein-Ternberg. Mitteilungen der Kommission für Quartärforschung der Österreichischen Akademie der Wissenschaften, 8 : 83-127. KUNST, G.K. (1996) - Femoral morphology of some Quaternary bears. Acta Zoologica Cracoviense, 39 (1) : 269-278. KURTÉN, B. (1955) - Sex dimorphism and size trends in the cave bear Ursus spelaeus Rosemüller and Heinroth. Acta Zoologica Fennica, 90 : 1-47.

PEREGO, R., E. ZANALDA & A. TINTORI (2001) - Ursus spelaeus from Grotta sopra Fontana Marella, Campo dei Fiori Massif (Varese, Italy) : morphometry e paleoecology. Rivista Italiana di Paleontologia e Stratigrafia, 107 (3) : 451-462. RABEDER, G. (1991) - Die Höhlenbären von Conturines. Entdeckung und Erforschung einer Dolomiten-Höhle in 2800 m Höhe. Athesia, Bozen, 125 p. RABEDER, G. & D. NAGEL (2001) - Phylogenetic problems of the Alpine Cave Bears. Cadernos Laboratorio Xeológico de Laxe Coruña, 26 : 359-364. REISINGER, C. & J. HOHENEGGER (1988) - Sexual dimorphism in limb bones of Late Pleistocene cave bear (Ursus spelaeus, Carnivora, Mammalia) from three caves in Eastern alps (Austria and Italy). Bollettino della Società Paleontologica Italiana, 37 : 99-116. ROSSI, M. & G. SANTI (2001) - Gli ursidi della Grotta dellʼOrso (Laglio, Como, Lombardia, Italia Settentrionale). Analisi morfometrica degli arti : indagine preliminare. Atti della Società Italiana di Scienze Naturali e del Museo Civico di Storia Naturale di Milano, 141(2000) (2) : 329-336. ROSSI, M. & G. SANTI (2002) - Gli ursidi dei Covoli di Velo (Verona) e di S. Donà di Lamon (Belluno). I – Preliminare analisi morfologica e morfometrica dei resti craniali e mandibolari. Bollettino del Museo Civico di Storia Naturale di Verona, sezione di Geologia, Paleontologia e Preistoria, 26 : 33-41. RUSTICHELLI, S. (1993) - Importanza delle collezioni museali per la conoscenza dei mammiferi pleistocenici. Studio morfometrico di una popolazione di Ursus spelaeus. Museologia Scientifica, 10 (3-4) : 269-281. SANTI, G. & M. ROSSI (2001a) - Bears from the Buco dellʼOrso Cave (Laglio-Como, Lombardy-Northern Italy). I : Morphometric study of the cranial and mandibular fossil remains. Atti Ticinensi di Scienze della Terra Pavia, 42 : 75-100. SANTI, G. & M. ROSSI (2001b) - Archaic and recent Ursus spelaeus forms from Lombardy and Venetia region (North Italy). Cadernos Laboratorio Xeológico de Laxe Coruña, 26 : 317-323. SANTI, G., M. ROSSI & S. POMODORO (2003) - Cave bears remains from the Buco dellʼOrso cave (Lombardy-Italy). Part III – Morphometric analysis of metapodial bones. Bulletin de lʼInstitut Royal des Sciences Naturelles de Belgique, Sciences de la Terre, 73 : 195-219. TORRES PEREZ HIDALGO, T. (1988) - Osos (Mammalia, Carnivora, Ursidae) del Pleistocene Ibérico (U. deningeri Von Reichenau, U. spelaeus Rosenmüller-Heinroth, U. arctos Linneo). I Filogenia, distribution stratigrafica y geografica. Estudio anatomico y metrico del craneo : 3-46. II Estudio anatomico y metrico de la mandibula, hioides, atlas y axis : 220-249. III Estudio anatomico y metrico

Plate V Ursus spelaeus ROSENMÜLLER, 1794. Delle Streghe Cave (Sambughetto Valstrona). A – V° metacarpus specimen MSNM V 4843, medial view, B – I° metatarsus specimen MSNM V 4925, plantar view, C – II° metatarsus specimen MSNM V 4934, lateral view, D – IV° metatarsus specimen MSNM V 4947, medial view, E – IV° metatarsus specimen MSNM V 4946, lateral view, F – V° metatarsus specimen MSNM V 4961, medial view, G – V° metatarsus specimen MSNM V 4960, medial view.

Plate V

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del miembro toracico, carpo y metacarpo : 359-412. lV Estudio anatomico y metrico del miembro pelviano, tarso, metatarso y dedos : 516-577. V Dentition decidual, formula dentaria y denticion superior : 660-714. Vl Denticion inferior : 886-940. Boletín Geológico y Minero. TSOUKALA, E., G. RABEDER & S. VERGINIS (2001) - Ursus spelaeus and Late Pleistocene associated faunal remains from Loutraki (Pella, Macedonia, Greece) - Excavations of 1999. Cadernos Laboratorio Xeológico de Laxe Coruña, 26 : 441-446. VENZO, S. (1954) - Osservazioni sulla fauna delle grotticelle di Sambughetto Valstrona e sugli stadi würmiani del Lago dʼOrta (Novara). Atti della Società Italiana di Scienze Naturali e del Museo Civico di Storia Naturale di Milano, 93 (3-4) : 409-431.

VIRANTA, S. (1994) - Limb bone proportions and body mass of the cave bear (Ursus spelaeus). Historical Biology, 7 : 239250. WEINSTOCK, J. (1999) - The upper Pleistocene mammalian fauna from the Grosse Grotte near Blauberen (Southwestern Germany). Stuttgarter Beiträge Naturkunde Serie B, 277 : 1-49. VON DEN DRIESCH, A. (1976) - A guide to the measurement of animal bones from archaeological sites. Peabody Museum Bulletin, 1 : 1-136.

Accepté novembre 2004