The contractor, Phil Anderson, halted further excavation, requesting several ..... of Vertebrate Paleontologists 65th Annual Meeting, Oct. 19-22, 2005 Mesa, AZ, ...
Annual Fossil Preparation and Collections Symposium April 29-May 1, 2010 (Field Museum), Chicago, IL
Preservation techniques and documentation procedures of the collections at the Mammoth Site of Hot Springs, Inc., South Dakota by Olga Potapova, Larry D. Agenbroad, Don Esker and Justin Wilkins Mammoth Site of Hot Springs, Inc., SD; 1800 Hwy 18 Bypass, Hot Springs, SD
Introduction
Preservation Methodology
HOT SPRING MAMMOTH SITE STANDARD BONE STORAGE CONDITION REPORT FIELD # _75HS103____ (“Mighty Manfred”)__CATALOGUE (MSL) # DATE __September 7, 2006____ TAXON __M. columbi_____ELEMENT ___skull_with mandible and tusks SIDE: X N/A LEFT RIGHT COMPLETENESS: FRAG PROX DIST X COMPLETE INCOMPLETE Preparators: unknown (1975), K. Anderson, J. Cavin (1997-1999) BONE ASSESSOR___Olga Potapova_ Consolidant: Glyptal (1975), Butvar 98/Methanol (1997-1999) Repairs : plaster of Paris (1975 –1997)
The left (left insert) and right (right insert) tusk alveoli with the proximal tusk fragments. Both tusk fragments have circular and semi-circular cracks, stabilized with dark unknown (Glyptal or Butvar 98/ Methanol) consolidant. Alveoli covering tusk fragments are in extremely fragile condition.
Brief history of the Site excavations, new Museum building and storage conditions In 1974 – 1979 and 1983 the excavations of the sinkhole were followed by backfills after each season, and heavy equipment was used to uncover, move and close the excavation area. During these seasons the uncovered fossils were identified, mapped with a grid, consolidated with Glyptal, plaster jacketed and removed from the site. Some bones were left “in-situ” to be removed in the following season(s); these were consolidated, jacketed (if needed) and backfilled. The removed fossils were temporarily stored in available environmentally noncontrolled facilities offered by the Board members, private individuals, and different Hot Springs organizations. In 1976, a temporary plywood shack (ca. 960 sq. ft) was built over the specimens located in the southeast end to protect these from the elements and allow field crew members and seasonal preparators more time to work on fossils. In 1977 a new addition (ca. 80 sq.ft) was built over the mammoth skull “Winnie” (77HS147). This structure was in place through 1986, and disassembled after the erection of the new Museum over the sinkhole. In 1986 the Museum building (20,223 sq ft. bonebed enclosure) was built over the 19,200 sq. ft (or 99%) area of the sinkhole. Since this year the excavations were conducted in the new enclosure significantly diminishing the summer heat and protecting exposed bones from the elements. Two sections of large windows that faced southwest had UV protection. In summer 1986 the excavated bonebed became permanently “open” all year round and has never been backfilled since then. The new conditions of the “open” bonebed soon caused large desiccation crack development, some of them going through mammoth bones exposed on the bonebed. The cracks were photographed and videotaped, and their condition was monitored. To reduce vibration by visitors, concrete sidewalks were installed on the northeast, north, west and southwest sides of the sinkhole. The bones removed from the bonebed in 1986 – 2001 were stored in the “box car” enclosure in the bonebed and in the lab, both equipped with two-tier wooden shelving. The Lab occupied a separate building nearby the museum, had simple ventilation system and was temperature controlled. Heavy equipment (loaders, etc.) usage on the bonebed was terminated in 1989, shortly after the recommendations given by Dr. J. Saunders (1986), Andres (1986), and assessment of soil cracking by D.B. Fenn (1987). The bonebed procedures were written by Dr. Agenbroad (1986). In 1990 the control of fluctuating temperature was improved by insulation of the bonebed ceiling and walls and re-shingling of the roof. Eight ceiling fans installed in 1995 with intent to significantly improve distribution of the air and provide balanced temperature and humidity in the bonebed. In 1996 the environmental control was again improved by installation of the HVAC system consisting of two 15-ton Trake electric heat pumps. The HVAC significantly decreased the fluctuation of humidity levels that was correlated with uncontrollable temperature fluctuations, and brought the development of the bonebed cracks to complete (visible) stop. Since 1996 the bonebed “winter” temperature has been maintained at around 50°F, and the summer temperature at 70°F. In 2001 the new addition to the main building (the Museum Phase II Development) was completed; it was insulated and temperature controlled and included the J. Muller Exhibit Hall (3444 sq. ft), Dr. Larry D. Agenbroad Laboratory (966 sq. ft), molding and casting room (512 sq. ft), research library (213 sq. ft.), two offices, class room, and environmentally (temperature, humidity, and radiant light) controlled bone storage (1596 sq. ft). The bone storage was equipped with two rows of metal regular shelves and eleven movable “Compactor” metal shelf rows; all shelves were padded with archival Ethafoam™. Two sections of heavy duty metal open two-tier shelves (donated by the John T. Vucurevich Foundation in 2008) for supporting mammoth skulls and tusks were added in 2008. The new addition was equipped with a security system. Until spring 2003 plaster jacketed heavy and/or large fossils were removed from the bonebed by manpower or a tall metal tripod. Installation of the overhead crane in the bonebed in March 2003 enhanced the safety of excavated bones and sediment removal from the bonebed and significantly reduced risk of the bonebed damage, and provided safer conditions for the bonebed workers. Since summer 2003 the sediment collected into buckets is loaded into a heavy-duty orange parachute sling bag and lifted from the bonebed exclusively by crane. They are then loaded into wheel barrels and brought outside for screen washing.
Skull. The skull is stored in a plaster jacket supporting the frontal side of the specimen. The skull is missing both zygomatic arches. Teeth rows comprise two molars, left and right M2, both in full wear, and right M3 partly in wear. Left M3 is gone from the alveoli. Parietal parts are reinforced with the plaster of Paris. Tusk alveoli are partly gone on the dorsal sides, and have numerous cracks that are repaired with plaster of Paris or water putty. The frontal part of the skull is treated with Glyptal, but is current condition is not known.
A. Bone recovery techniques and consolidants Since 1974, the scientific direction and excavation supervision of the Site has been headed by Dr. Larry D. Agenbroad (Chadron College, Chadron NE; 1967-1978; and Northern Arizona University, Flagstaff, AZ, 1978-2003). Dr. Agenbroad conducted the excavations with techniques he used excavating archeological and strictly paleontological sites including the “Y” Buffalo Jump, Idaho (1969), Murray Springs, Sierra Vista, AZ (1966 - 1973) and Lehner Ranch II Mammoth Kill, Arizona (1974 – 1975), Canez Wash mammoth locality, AZ, and Cerros Negros mammoth locality, AZ, and Hudson-Meng Bison Kill, Nebraska (1971-1975). These digs range in age from 28,000 yr B.P. to 11,300 yr. B.P and represent a wide range of taphonomic and preservation conditions and techniques. The excavation methods of the Mammoth Site were the following (Potapova et al, 2002, Potapova, 2003, 2004, 2005; Potapova et al, 2007): from 1974 to 1983 the site had to be excavated and backfilled every season. The upper part of the backfilled sediments was marked by underlying plastic sheeting and removed by heavy equipment. The lower portion of the sediments with bones and about 3 ft of dirt over them were uncovered with shovels first, then trowels and brushes, and detailed with wooden picks. After removal of sediments, the bones were consolidated with the clear Glyptal ® (# 1202 for initial application, #1276 for final finish) varnish (mixed with 1 to 3 parts of xylene) and if needed, glued using Duco™ cement. Consolidated bones were labeled, hand-mapped using a simple grid system correlated with datum, plaster jacketed (if needed), and removed (with pedestal dirt as a filler between bone and bottom cast) from the Site. If necessary, bones were plaster jacketed, covered by the backfill and left in sediments until next season. Plaster of Paris was used for filling voids and bone’s cosmetic repair. In certain circumstances (wet unstable bone) Elmer’s ® glue was applied before bonding with Glyptal ® (Hanson, 1987). These excavation and field preservation techniques were widely used at those times by paleontologists; the Glyptal diluted in acetone (or xylene) had the good (short-term, but not yet known that time) properties providing short time drying, easy application, availability on the market, and reversibility. The Glyptal ® coating that formed a solid “exoskeleton” after repeated applications provided good support and protection for the backfilled bones and the bones excavated and stored in environmentally uncontrolled facilities. The Duco ™ cement and Elmer’s ® glue were used as a glue and filler, and selected due to its compatibility with the acetone and Glyptal ®. The seasonal (summer) excavations of the site under open air (in 1974 there was a canopy over a portion of the exposed bones) followed by backfilling the Site were conducted in 1975, 1976, 1977, 1979, and 1983 resulting in discovery of few complete and partial mammoth skeletons, but predominantly isolated large mammoth bones, molars and tusks and also a partial skeleton of the Short-faced bear (1983). Until the summer 1979 and discovery of the almost complete mammoth skeleton “Napoleon”, most of the unearthed bones were removed from the Site. In 1979 and 1983 and Dr. Larry D. Agenbroad completed identifying the Site’s boundaries and suggested to continue excavations that will allow leaving and preserving the specimens “in-situ”. His analyses confirmed that the Site represented a former sinkhole developed in karst rock by artesian spring filled with sediments. At that time there were few bonebeds with bones preserved “in situ” known in North America, all of which contained completely mineralized bones. The discovery of the sinkhole and its future preservation of non-petrified bones “in-situ” had to go through tough trial and experimenting. During the season of 1983 the field team started using new consolidant, the Butvar ® mixed with acetone, after consultations with the preparators from the Florida Museum of Natural History (Gainsville, FL), and Dr. Bijork (SDSM&T, Rapid City, SD). However, under the new building, hot and damp conditions of the 1986 summer season challenged the conservative methods of field bone preservation. Use of the Butvar® /acetone consolidant wasn’t effective; uncovered bones were wet and the Butvar ® applied on their surfaces was leaving milky white coating (Agenbroad, undated memo, p.5). Limited to the field season timeframe, powerful infrared heat lamps set up close to the bones were used to decrease the drying time of the bones and/or preservative (Agenbroad, 1986). Limited supply of Crazy Glue ® (on vertical cracks) and Water Putty ® dyed with dry colored Powder Tempera used for reconstruction purposes were used for bones in critical conditions (Agenbroad, undated). Since 1986 the Butvar 98® /Ethanol and Butvar 76® /Acetone has been used on the bonebed to consolidate and repair bones following recommendations by J. Snider (undated memo; 1988) and J. Saunders (1986) and guidelines for the subfossil bone treatment offered by other conservators (Shelton et al., 1995; Canadian Conservation Institute, 1983). In 1989 the test of treating bone with Arcysol ® copolymer dispersion was performed, with preparator’s recommendations (Anderson, 1989) that were not considered convincing for replacing of the Butvar consolidants. In summer 2004, following recommendations outlined by Fitzgerald (2005), we conducted experiments for using the Acryloid ® B72/Acetone consolidant in the lab conditions and found it efficient and appropriate. Since then, the bones removed from the bonebed are treated by Acryloid ® B 72/Acetone. B. Screen-washing Procedures. Screen washing techniques were used to recover microfauna (including invertebrates, ostracods, gastropods, and pelecypods). Screen-washing is one of the primary procedures performed during Mammoth Site excavations. We retrieve 16-18 tons of sediment per year, and a minimum of 10% of this is screen-washed. Through screen washing we find the remains of snail shells, and skeletal elements of toads, prairie dogs, ground squirrels, voles, pocket gophers, deer mice, rabbits and other small animals. These animals are very good indicators of the former paleoclimate and paleoenvironment in the region, not only because they occupy certain ecological niches, but also because these animals have a very restricted living area and do not migrate. Screen washing follows these steps: 1. Preparation - before sediment is collected, select a screen-wash area measuring 1 meter by 1 meter, and 10cm depth, and map its position. 2. Hauling sediment - all sediment that is excavated and cleaned off the bones in the bonebed is taken out by overhead crane, and then is delivered in bags or buckets (in vehicle, or trailer) to the screen-washing area. Every bag or bucket is labeled with the sediment location, date of excavation, and collector. 3. Screens – we use sets of two screens placing the ¼” screen on top of the 1mm screen. The top screen catches large rocks and cemented matrix that will not dissolve with water. The bottom screen allows sand, silt and clay to go through it, catching bigger pieces of sediment and small bones and shells. 4. Screen washing – when screens are set up, we gently pour about half of the bucket of sediment on the top screen, trying to pour the sediment so it covers the screen evenly. We do not spread the sediment by hand, and do not push it through the screen, because this rough handling will harm fragile snail shells and rodent bones. Water will do the job! We hold the “shower-head” vertically over the sediment and collect and throw away the large rocks, continuing the procedure until all sand and silt has been washed from the top screen. 5. Specimen collection - when the sediment is dry, we brush it with a ½” paint brush to the screen frame corner and pour it into a zip-lock bag, placing the label inside the bag. If microfauna fossils are spotted (rodent skulls, mandibles or teeth), those are collected immediately and placed in a glass vial before putting the dried sediment and its label in the zip-lock bag. Processed specimens are brought back to the lab the same day. 6. All dried sediment is processed for bone and snail shell remains in the lab.
Documentation The mandible 75HS103. The bone and teeth are discolored by excessive Glyptal application discolored into dark brown and reddish-brown. Both condyles are broken off. More detail description follows below.
Left side of the mandible, buccal view is exposing discolored surface, longitudinal cracks and teeth in poor condition stabilized with the Glyptal.
Basioccipital region: The basal part of the skull is damaged in numerous places. Right condyle (arrow) is misplaced and attached to the skull surface. Left condyle is missing. Thick coating of the Glyptal is covering the whole surface area.
A. Organization. Information of any activity done to the bone, including mapping, excavation, and preservation is filled in the Condition Report Form and individual Record Card if the bone is removed. Following the IMLS Conservation and Documentation Surveys (Patterson, 1989; Fitzgerald, 2005, Shelton, 2005), the Mammoth Site collection staff and the Mammoth Site Collections Committee consultants developed the Mammoth Site Field Data Collection Procedures manual, the Standard Field Data sheet, and the Standard Bonebed Specimen Condition Report, making the data collection process consistent and efficient. The Standard Field Data Sheet is used to keep track of every new or unmapped bone, with details on its location, orientation, position, and so on, and requires basic knowledge of GIS and osteology. The Standard Bonebed Specimen Condition Report (Condition Report) form is used to keep track of every bonebed specimen that staff, volunteers, or interns work on. The Condition Report and the Record Card must be completed every day for every specimen that is touched (e.g., removing old consolidant, repairing a damaged bone or re-consolidating bones). Upon the discovery the bone, the entry and collections a bone’s data (field number, identification, date, etc.) is filed into the Record Card – the primary source of information. When excavated, the bones are labeled with the field numbers, which in appearance slightly change through the years. Currently field numbers contain the first two-digit numbers corresponding to year of excavation, two capital letters HS, FG, GE, CO, etc. standing for “Hot Springs”, “fragment”, “geological feature”, “coprolite”, etc. and followed by consequential number corresponding to number of bone (feature) uncovered during corresponding year (an example is 78HS023). Every bone removed from the bonebed is checked in the “Lab Check In” Journal in preparation laboratory to keep track of incoming bones and date of removal. This procedure was set up in summer 2006 (The Mammoth Site Bonebed Procedures, 2006). Since 2005 only archival labeling materials are used on bones: white archival acrylic paint (base) as a “white out”, acid-free ink (Pigma Micron) pens of different sizes, and Acryloid ® B72/acetone for coating labels.
A. Monitoring devices In 1986 – 2004 the bonebed was monitored by thermograph/hydrographs installed in the northeast and southwest areas of the sinkhole. In 2004 those were replaced with HOBO dataloggers allowing continuous monitoring and collection of temperature, humidity, and radiant light fluctuations and store the information in the database for further analyses and comparisons. HOBO dataloggers were also added to the bone storage and laboratory. Soon after the replacement, radiant light fluctuations monitored by HOBO dataloggers revealed high peaks in fall and spring, and demonstrated the same pattern over four years (2004-2008). The problem was addressed in April 2008; two large sections of the bonebed windows facing south-east were covered by 60% to 90% non-transparent shades, which instantly reduced the level of radiant light. The radiant light is continued to be monitored by the HOBO data-loggers that are set up on the east, southeast and southwest ends of the sinkhole.
Collections Safety Measures The bonebed enclosure is equipped with fire/smoke detectors and has security alarms since 1987. The video security system was added in 1988. The old laboratory building (currently women’s dorm) has been equipped with security system since 1988. The new laboratory and bone storage (the new addition built in 2001) have fire/smoke detectors and security since 2001, and video cameras have been in place since 2009. Flood detectors are installed in the bone storage in 2007. There were no theft losses, or losses to disasters reported in the museum’s collections since 1986. To enhance the fossil secure handling, the Mammoth Site Laboratory Policy was drafted in 2004, and later on, completed with significant additions in 2008. In 2005 a complete rewrite of the Emergency Operation Plan was performed. Since that year, the Plan is annually updated, the personnel is trained and given a copy, and local Fire Department performs yearly checkups of the building (The Mammoth Site EOP, 2009). In 2009 we started performing a yearly checkup of the bonebed overhead crane.
Data The Condition Report Forms are stored in the research library, and Record Cards are stored in the fireproof cabinet in bone storage. Original hardcopies of the Record Cards, Field Notes Journal (1974-2002), Bonebed Condition Reports, Journal of Donated Items, Journal of Outgoing Specimens (for studies) are kept in fireproof cabinet in the bone storage. All digital data (databases) are backed up monthly on the MS server. In addition, the original documentation (journals, field notes, record cards, etc.) are copied (2007) and currently stored in the Hot Springs (SD) Wells Fargo Bank. The ArcView ® GIS database stores the information of all bonebed bones that were re-mapped in 2007-2010 funded by the IMLS MFA grant. The ArcView ® GIS database is currently used for the bonebed specimens (over 1,200) inventory and tracking. The Microsoft Access ® database is used for the removed from the bonebed bones and screen washed microfauna specimens (over 2,000 specimens/samples) records that are stored in the Bone storage or being prepared in the Laboratory. By the end of the year 2009 both databases became merged and searchable. The electronic databases are monthly backed up on the “mapping computer” and Mammoth Site server. Fossil collection From 2001 the collections are stored in environmental controlled room, a Bone storage, which is equipped with the Compactor ® storage metal shelves, and heavy-duty metal shelving for skulls and tusks (funded by J.J. Vucurevich Foundation in 2007). In 2005 all non-archival storage containers, boxes and trays were replaced by archival materials.
1600
Interns, volunters and group hours logged in the Lab in 2002 - 2009
1400 Elderhostel +PE
1200
Volunteers (incl EW)
1000 800 600 400 200
2002
2003
2004
2005
2006
2007
2008
2009
2010
Year
Interns, volunteers and groups All categories of the Mammoth Site preparators listed below made a significant impact of the fossil’s curation, conservation and documentation. Without their contribution and devotion we wouldn’t be where we are right now. A. The Mammoth Site Summer Internship program The Program was started in 2002 and is on-going. The yearly crop of interns, which consists of six to eight students, work at the Mammoth Site during 10-12 weeks, splitting responsibilities for guiding tours in the bonebed, doing preparation work in the lab, and excavating, mapping and cleaning the bonebed. So far, from 2002 to 2009 we had 55 undergraduate and postgraduate students (two of them volunteered) from 21 US states, Canada, and the UK. The students logged over 6,820 hours in the lab. We educated on field methods we use here at the site, gave them a unique experience working at an on-going excavation site and a glimpse into the “mammoth world”. Hopefully we have a positive impact in their future careers in geology and paleontology.
B. Mapping and Database. Mapping has been an ever-present task at the Mammoth Site and one of the most reliable forms of documentation we have. In 1974-1994 the Mammoth Site used a string-grid for mapping and an entirely hand-drawn system of cartography. In 1994 it was replaced by a Nikon C-100 laser transit in conjunction with AutoCAD® and AcrGIS ® software, which was gradually updated with later versions of the GIS software. In 2007 the whole system was upgraded with ArcGIS 9.4 mapping software, supported by a Trimble 5600 robotic transit and “crane-enhanced” photography (Esker, 2009; McCartey, 2009; Agenbroad et al., 2010). It was at this point that we acquired a Trimble 5600 robotic total station, through a grant from the Institute of Museum and Library Services. This machine allows us to record extremely accurate data on positions of the bones in the bonebed. Control points are established around the bones, measured with the transit, and then all are photographed with a high resolution camera (until January 2010, a 4.1 Mpxl Canon ® Powershot A520; now a 14.9 MP Canon Powershot G10). Detailed notes on the date, discoverer, bone condition, general location, and initial interpretation are also recorded at this time, both in a field book and on specially designed EDM sheets, and later transferred to ArcGIS. The high resolution photograph is digitized into an ArcGIS (v. 9.3.3) shape file with the bone’s spatial data intact. The ArcGIS database is a series of three ArcGIS layers that contain up to 29 fields of data. These fields are available as open-ended for entering field notes and other non-standard descriptions and as pull-down lists for standardized descriptions (taxa, element, portion, completeness, etc.). The data is generated when adding the drawn ArcGIS shape file to the appropriate map layer (bone, fragments, traces, etc.) and filling out these fields. The database has been integrated with the Mammoth Site Laboratory database for those bones which have been removed to the lab. The integrated database is a Microsoft Access database, which links the two sets of data based on a common bonebed field number (**HS***).
Plantar view of upper teeth region – three molars, and palatine region are covered by the Glyptal coating. There are few visible cracks on the bone surface, which are sealed by the Glyptal.
B. Volunteers (and unpaid by the MS personnel) Volunteer fossil bone preparators have been at the Mammoth Site from its discovery and excavating, jacketing, and documenting the fossils. Hours they logged during their volunteering were impossible to collect for this presentation. However, from 2002 to 2009 we have a very good record of their work: 14 local and out-of-state volunteers logged the total of over 4,546 hours in the lab (98%) and bonebed, significantly eliminating the backlog of unprepared bones removed from the bonebed. C. Groups (Elderhostel/Exploritas, Project Exploration Chicago) Presence of these groups at the Mammoth Site is short, but very important for recruiting of future volunteers and influencing students in pursuing geological and paleontological degree. We educate seniors and juniors in excavating and recovering fossils from the Site, and preparation techniques. So far, from 2002 to 2009 those groups logged on over 1,245 hours in the laboratory preparing bones.
References:
B. Radiant Light Control. In two main areas (the bonebed and bone storage) housing fossils has been the primary concern since the bonebed became an open pit all year round (since 1986), and bones were removed for storage (1975). With a new building addition in 2001, the bone storage room was properly equipped with environmental control devices and selves. The bonebed windows had a UV protection, but were unable to allow proper amount of radiant light reaching the bonebed, causing extremely high records during equinox months (October and March-April). In 2008 the windows were covered by black mesh sheets that significantly reduced the readings of radiant light. C. Bonebed Humidifier Much of the damage to our specimens here is the result of humidity fluctuations. Both the sediment and bones at The Mammoth Site are hygroscopic, meaning that they absorb and release moisture from the air, and expand and contract as they do so. This cycle of expansion during high humidity and contraction during dry periods causes innumerable cracks to form in the bonebed and the bones. The Canadian Conservation Institute (CCI), a leading authority, recommends that humidity not fluctuate more than +/-5% in 24 hours, or more that +/-3% in one hour, and that humidity remains between 45% - 55%. Before we took measures to alleviate this problem, bonebed humidity varied between 30%-70% and fluctuated as much as 38% in a single day (see graphs). To remedy this problem the Mammoth Site needed a humidity control system. In 2007 the Mammoth Site pursued the bonebed humidity control study, which was performed through the Skyline Engineers. In 2009 we were awarded with the IMLS CPS grant for installation of the humidifier and dehumidifier on the bonebed, which was completed in winter 2010.The system works by monitoring bonebed humidity via humidistats, and activating a steam humidifier or electric coil dehumidifier when the RH in the bonebed strays from the ‘safe zone’ recommended by the CCI. Since activating the system, daily humidity fluctuations have dropped to 2%.
C. Storage.
0 2001
Right half of the mandible, frontallingual view, with the teeth are in extremely poor condition. Multiple large and deep cracks are going across and along the M2 axis, and consolidated with the Glyptal.
Environmental monitoring and control
C. 3D Photogrammetry The photographs taken using the crane-mounted camera system has also opened the door to a new dimension of mapping: the third dimension. For several years The Mammoth Site has been looking into LIDAR mapping, a laser-scanning based technique that yields a three dimensional point cloud, showing the topology of the bonebed in a way that two dimensional mapping cannot. Lamentably, LIDAR is an expensive technology – beyond The Mammoth Site’s means at this time. With the photographs taken from the Crane-mounted camera, however, we’ve managed to produce a three dimensional point cloud regardless. By feeding multiple views of a single area of the bonebed into Microsoft’s Photosynth software, a LIDAR-style 3D map can be generated. The initial problem with this system was that all of the data generated this was stored only on Microsoft’s servers, making the data unavailable for analysis. Fortunately, we received permission from Microsoft to use WireShark software to intercept the data packets containing the point cloud. After some manipulation in Microsoft Excel, the data can be viewed as 3D mesh in Visual Computing Lab’s MeshLab software. MeshLab allows the user to make three dimensional measurements of meshes. By comparing measurements made within the computer with those made in the bonebed, we’ve determined that Photosynth introduces distortion on the order of 2.5% -- perhaps even less. There are several potential bonebed applications for this new technology. First, by distributing this data to other researchers in the field, they will be able to take accurate measurements of the spatial relationships between bones, and measure the morphology of individual bones. Second, by breaking old films of work at the site into individual frames, it should be possible to make accurate 3D meshes of the conditions at the site during various points during the excavation. With a sufficient number of images, it should be possible to precisely reconstruct the position of bones that have long since been removed.
Hours
The Mammoth Site is a natural, geologic-hydrologic natural trap. Roof collapse of an underground solution cavern (similar to Wind Cave National Park) led to a sinkhole which served as a conduit for thermal artesian water. The sinkhole contained a warm water pond which provided perennial green vegetation at the water’s edge. That combination proved to be fatal to young Columbian mammoths (Mammuthus columbi). Trap was selective for the behavior of young, male mammoths. At the close of the 2009 field excavation we had recovered remains of a minimum of 58 mammoths, by tusk count. Approximately 40% of the site remains to be excavated to the current depth of excavation (drill cuttings reveal a continuum of at least 100 more meters of vertical, fossil-bearing, sinkhole sediments. In addition to the proboscidean remains, we have collected a host of smaller fauna, both vertebrate and invertebrate. The site was discovered during a land development project on the southern limits of Hot Springs, in 1974. Removal of the top of a small, local, hill exposed numerous large bones. The contractor, Phil Anderson, halted further excavation, requesting several agencies to assess the importance of the deposit. Having been turned down by four agencies, he was about to continue excavation. Dr. Agenbroad (formerly of Chadron State college, Nebraska) agreed to test the site to see if it warranted further excavation. The results of two exploratory seasons revealed a dense concentration of remains of Columbian mammoths contained within limits of the sinkhole sedimentary fill. The 1975 test season exposed the complete cranium of a Columbian mammoth with tusks attached and the mandible only slightly down-dropped. That discovery prompted funding from the National Geographic Society, and Earthwatch Institute. Mr. Anderson sold the property, at his cost, to a newly formed group, The Mammoth Site of Hot Springs, South Dakota, Inc. Several field seasons proved the site was large and rich in faunal remains. At the close of the 1979 field season we started a self-moratorium on further excavation, until a structure could be erected over the site (in 1985 – 86). The Mammoth Site is unique in several aspects: 1 – it is the largest concentration of Columbian mammoth remains (in the world) that are still entombed in the sediments that filled the trap that had sealed their fate, 2 – it was selective for the behavior of young, male mammoth, as alluded to, above, 3 – the remains left in situ, for public view and education, as well as for researchers, 4 – sedimentary analyses have concluded the trap was operational for a period of between 300 and 700 years, at about 26,000 radiocarbon years ago, 5 – the site serves as a research facility with annual excavation, provides internships and scholarships for a dynamic paleontological project, 6 – it provides a glimpse into the late Pleistocene paleoenvironment of the southern Black Hills of South Dakota, for all to study and enjoy.
Both mandible halves are reinforced by a pedestal applied directly on the bone surface and consist of plaster of Paris and metal pipes. Symphysis process and left coronoid process are reconstructed by plaster of Paris and painted with matching color.
Left (left insert) and right (right insert) sides of the skull, Two M2 and one left M3 are visible. All surfaces have dark brown color due to the excessive Glyptal application. Both parietal bones are visible at the bottom are restored with painted plaster of Paris.
Ventral side of the maxilla bones (alveoli) – covered by numerous cracks, and has areas with missing bone filled in with the plaster of Paris.
Caudal side of the mandible (insert below). Lingual side of the left mandible was repaired by plaster of Paris and painted with matching color. The most surfaces, particularly around the molars and symphysis are discolored by the Glyptal. Back sides of both mandible halves have missing bony walls exposing roots of the last molars.
Anderson, K., Davids, J., and T. Hodorff, 1994. Nonpetrification preparation. In: (Leggi P., and P. May, eds.) Vertebrate Paleontologicval Techniques. Vol. 1. Cambridge University Press, New York, NY. P. 140-145. Agenbroad, L., Esker, D.A., and J.W. Wilkins, 2010. The Mammoth Site of Hot Springs SD: the mapping of the long term excavation site. Abstr. Rocky Mountains Section 62nd Annual Meeting Agenbroad, L.D., 1986. Memodandum on dig procedure. I. Dig Procedure. Document on the MS Research Library file, p. 8-11. Agenbroad, L.D. (undated). Synopsis of Site Developmental History. Document (typewritten) on the MS Research Library file,7 p. Anders, J.J., 1986. Recommendations to the Site Board concerning the maintenance of the mammoth Site of Hot Springs, South Dakota. Document on the MS Research Library file Anderson, K., 1989. Report on Acrysol tests (Acrylic Copolymer Dispersion). Document (typewritten) on the MS Research Library file. Collogan, D. (undated). Early notes on Mammoth Site Bone Pile at Hot Springs, South Dakota. The Mammoth Site Archives: Document (typewriter) on the MS Research Library file, 1 p. Esker, D., 2009. It’s All about Context: Remapping mammoth bone bed with ArcGIS. ESRI GIS Educator, Summer 2009. P. 6-7. Fenn, D.B., 1987. Assessment of Soil Cracking Problem in Display Pedestals at the Mammoth Site, Hot Springs, South Dakota. The Mammoth Site Archives: Report on the MS Research Library file, 9 p. + Appendix 8 p. Fitzgerald, G.R., 2005. Conservation Assessment of the Mammoth Site of Hot Springs, South Dakota. The Mammoth Site Archives: Report on the MS Research Library file, 27 p. Hanson, D., 1987. Personal account of the early days of the Mammoth Site in Hot Springs. The Mammoth Site Archives: The document (typewriter) on file, MS Research Library, 6 p. Erin McCarthy, 2009. Paleontologist: This is My Job. http://www.popularmechanics.com/technology/gadgets/news/4269373 Patterson, C., 1989. General Survey Report. The Mammoth Site of Hot Springs, South Dakota, Inc. The Mammoth Site Archives: Document (typewritten) on the MS Research Library file. 11p. Potapova, O., K. M. Thompson, L.D. Agenbroad, and S. Holte 2007. From Salvage Operation To In Situ Preservation: Techniques Used In Conservation At The Mammoth Site Of Hot Springs, South Dakota. Abstr. 67th SVP Meeting, October 17-20, Austin, TX. Journal of Vert. Paleontology, Vol. Suppl. 2007. Potapova, O., 2005. Reconstruction and conservation of Columbian mammoth (Mammuthus columbi (Falconer), 1857) tusk under monitored conditions. Abstr. Society of Vertebrate Paleontologists 65th Annual Meeting, Oct. 19-22, 2005 Mesa, AZ, USA Potapova, O., 2004. Conservation and restoration of a 26,000 years old Columbian Mammoth (Mammuthus columbi (Falconer), 1857) tusk from the Mammoth Site, South Dakota. Abstr. Society of Vertebrate Paleontologists 64th Annual Meeting, November 3-6, Denver, CO. P. 102A. Potapova, O., 2003. Specimen collection and methods of mammoth bones preservation at the Hot Springs Mammoth Site, Hot Springs, South Dakota. Abstr. 3rd Mammoth Conference, Whitehorse, May 24-29. Potapova, O., Agenbroad, L. and K. Anderson, 2002. The Mammoth Site: 27 years history of experience digging, rescuing and preserving mammoth’s bones. Abstr. 10th Annual “Island in the Plains” Black Hills Archaeological Symposium. April 6th, Deadwood, SD Sears M., McDonnel J.E., 2007. Radon Analyses Report. The Mammoth Site Archives: Document (typewritten) on the MS Research Library file, 2 pages. Snider, J., 1988. Guidelines for a Statement of Policy and Philosophy for the preservation of Fossil Bone from the Mammoth Site of Hot Springs, South Dakota. Document (typewritten) on the MS Research Library file, 7 p. Snider, J. (undated). Recommendations for preparation and preservation of bone from the Mammoth Site, Hot Springs, South Dakota. The Mammoth Site Archives: Document (typewritten) on the MS Research Library file, 6 p. Shelton, S., 2005. Collections Management Assessment Report. Mammoth Site of Hot Springs. Document on the MS Research Library file. 14 p. Shelton A.Y., and J. S. Johnson, 1995. The conservation of subfossil bone. In: (Chris Collins ed.), The Care and Conservation of Paleontological Material, pp. 59-71. Oxford: Butterworth-Heinemann Ltd. Canadian Conservation Institute. 1983. Care of ivory, bone, horn and antler. Canadian Conservation Institute Notes 6(1):1-4. (Minimum RH for bone – 45%, max T + 25C (77F) for ivory and bone) The Mammoth Site Bonebed Procedures, 2009. Approved by the Mammoth Site Board of Directors April 28, 2009. Document on the MS Research Library file The Mammoth Site Emergency Operation Plan, 2009. Approved by the Mammoth Site Board of Directors April 28, 2009. Document on the MS Research Library file The Mammoth Site Collections Management Policies, 2003. Document on the MS Research Library file. Sears M., McDonnel J.E., 2007. Radon Analyses Report. Document on the MS Research Library file, 2 pages.
