SVP 75th Annual Meeting
Meeting Program & Abstracts
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SOCIETY OF VERTEBRATE PALEONTOLOGY
OCTOBER 2015
ABSTRACTS OF PAPERS
75
th
ANNUAL MEETING
Hyatt Regency Dallas
Dallas, Texas, USA
October 14 ² 17, 2015
HOST COMMITTEE
Stephen Cohen; Anthony R. Fiorillo; Louis Jacobs; Michael Polcyn; Amy
Smith; Christopher Strganac; Ronald S. Tykoski; Diana Vineyard; Dale
Winkler
EXECUTIVE COMMITTEE
John Long, President; P. David Polly, Vice President; Catherine A. Forster,
Past-President; Glenn Storrs, Secretary; Ted J. Vlamis, Treasurer; Elizabeth
Hadly, Member-at-Large; Xiaoming Wang, Member-at-Large; Paul M.
Barrett, Member-at-Large
SYMPOSIUM CONVENORS
Larisa R. G. DeSantis; Anthony R. Fiorillo; Camille Grohé; Marc E. H.
Jones; Joshua H. Miller; Christopher Noto; Emma Sherratt; Michael
Spaulding; Z. Jack Tseng; Akinobu Watanabe; Lindsay Zanno
PROGRAM COMMITTEE
David Evans, Co-Chair; Mary Silcox, Co-Chair; Heather Ahrens; Brian Beatty; Jonathan
Bloch; Martin Brazeau; Chris Brochu; Richard Butler; Darin Croft; Ted Daeschler; David
Fox; Anjali Goswami; Elizabeth Hadly; Pat Holroyd; Marc Jones; Christian Kammerer;
Amber MacKenzie; Erin Maxwell; Josh Miller; Jessica Miller-Camp; Kevin Padian;
Lauren Sallan; William Sanders; Michelle Stocker; Paul Upchurch; Aaron Wood
EDITORS
Amber MacKenzie; Erin Maxwell; Jessica Miller-Camp
Poster Session II (Thursday, October 15, 2015, 4:15 - 6:15)
PLASTERED: AN EXAMINATION OF UNORTHODOX JACKETING MATERIALS
BIRTHISEL, Tylor A., Natural History Museum of Utah, Salt lake city, UT, United States of America, 84108
Specimen jackets are created with burlap, water, and plaster. During remote field work, however, these ingredients can occasionally be in short supply or absent and decisions need to be made on the viability of removing specimens. Several creative materials have been proposed and executed to supplement any missing supplies keeping with best practice methods. Various cloths; such as cotton/polyester t-shirts, denim jeans, and cotton socks are typically found in abundance in most field camps, but these materials are not suitable replacements for durable, easy-to-use burlap. Liquids, such as sports drinks or beer are familiar in many field packs or coolers; however, when substituted do not form reliable bonds with the plaster. If plaster is in short supply or unavailable, paper towels soaked in consolidant and mud that is impregnated with consolidant can be a safe substitute for a plaster specimen jacket in limited uses. Duct tape does not provide enough support and protection to safely transport specimens back to the lab and is not a viable solution. Since specimen jackets often reach large sizes, a jacket many require support braces made of tree branches, wooden 2 x 4s, or fence posts, although other materials can be used for a support brace when those supplies are not available. This study WHVWVDQGH[DPLQHVSDVWDSSOLFDWLRQVRIYDULRXVµTXLFNIL[¶VROXWLRQV and demonstrates the viability of each material in the creation of plaster specimen jackets to determine which solutions are safe for the fossils during transport, versus when it is better to leave the specimen in the field and return with proper supplies.
Poster Session IV (Saturday, October 17, 2015, 4:15 - 6:15)
FUNCTIONAL AND GEOMETRIC MORPHOMETRIC ANALYSIS OF A MIDDLE MIOCENE BANDICOOT (MARSUPIALIA, PERAMELEMORPHIA) SKELETON FROM THE RIVERSLEIGH WORLD HERITAGE AREA, AUSTRALIA
BLACK, Karen H., University of New South Wales, Sydney, Australia; TRAVOUILLON, Kenny J., The University of Queensland, St Lucia, Australia; MYERS, Troy J., University of New South Wales, Sydney, Australia; ARCHER, Michael, University of New South Wales, Sydney, Australia; HAND, Suzanne J., University of New South Wales, Sydney, Australia; WILSON, Laura A., University of New South Wales, Sydney, Australia
The marsupial Order Peramelemorphia comprises four families: the extant Peramelidae (bandicoots), Peroryctidae (forest bandicoots of New Guinea), and Thylacomyidae (bilbies); and the extinct Yaralidae; with several fossil species of uncertain familial affinity designated as Peramelemorphia incertae sedis. Extant taxa (approximately 20 species) are characteristically omnivorous, small to medium sized (0.1±2.5 kg) semi-fossorial/fossorial marsupials with a quadrupedal bounding gait. They occupy a range of habitats in Australia and New Guinea from desert to rainforest. Twelve pre-Pliocene taxa are currently described on the basis of cranial and/or dental material, yet none is known from its postcranial skeleton.
In this study we use qualitative morphological and 2D geometric morphometric data to analyze a partial skeleton of a new species of bandicoot from a middle Miocene paleokarst deposit, AL90 Site, in the Riversleigh World Heritage Area, northwestern Queensland. This deposit has been U-Pb radiometrically dated at 14.7±15.1 Ma. The specimen preserves the skull, left and right dentaries, the fore-and hindlimbs, and elements of the manus, pes and axial skeleton. Cranio-dental morphology indicates the species lies outside crown-group Peramelemorphia. The estimated body weight of the new species based on predictive marsupial cranio-dental regression equations is approximately 250 grams. Dental morphology, particularly the absence of a well-developed metaconule on the upper molars, indicates a more insectivorous diet than extant bandicoots, more comparable to smaller modern dasyurids. Qualitative and metric analyses of the appendicular skeleton indicate a less-specialized postcranium than modern bandicoots, which possess numerous musculoskeletal adaptations for scratch-digging and /or fossorial behaviors. Most notable is the relatively gracile bones of the antebrachium of the fossil taxon which is in striking contrast to the short, robust forearm of many modern bandicoots. Collectively, these data indicate a more generalized niche for this species than crown group peramelemorphians and may support suggestions that archaic bandicoots filled an ecological niche later dominated by small dasyurids during the late Cenozoic.
Grant Information
Funding for Riversleigh research is provided by the Australian Research Council (ARC) grants to M. Archer, S. Hand and K. Black (DP1094569, DP130100197, and DE130100467).
Poster Session I (Wednesday, October 14, 2015, 4:15 - 6:15)
NEW DATA FOR THE PALAEOBIOGEOGRAPHICAL HISTORY OF THE GENUS PELOBATES (AMPHIBIA, ANURA) IN ITALY
BLAIN, Hugues-Alexandre, Institut Català de Paleoecologia Humana i Evolució Social (IPHES), Tarragona, Spain; DELFINO, Massimo, Università di Torino, Torino, Italy; PRIKRYL, Tomas, Institute of Geology, Academy of Sciences of the Czech Republic, Prague, Czech Republic; BERTO, Claudio, Università degli Studi di Ferrara, Ferrara, Italy; ARZARELLO, Marta, Università degli Studi di Ferrara, Ferrara, Italy
Spadefoot toads (Pelobatidae, Anura) are quite rare in the Italian fossil record, being recorded only in the Late Pliocene of Arondelli (Piedmont Region, north-western Italy) and in the Early Pleistocene of Pirro 21 (Apulia, south-eastern Italy). Here we describe for the first time the abundant fossil remains from the Early Pleistocene fissure of Pirro 13 (Apulia, southern Italy) attributed to Pelobates syriacus, a toad currently living in the southeast of the Balkan Peninsula, Caucasus and Middle East. It is the first time that this species is reported in the Italian fossil record. In spite of this only fossil occurrence, P. syriacus is shown to have good dispersal abilities for toads, and dispersal routes to reach the Apennine Peninsula may have been favored by a lower level of the Adriatic Sea, furnishing new habitats suitable for spadefoot toads. Our finding is confirmation that the
range of this species was broader in the past than at present. Noteworthy is that according to niche modeling, the potential ecological niche for P. syriacus is extended outside its known range, westwards in the Mediterranean (e.g., the Italian Peninsula) and northwards in the Pannonian Basin and north of the Black Sea and of the Caucasus in a similar way during glacial and interglacial periods.
Grant Information
CGL2011-13293-E/BTE, CGL2012-38358, and SGR2014-901 Poster Session III (Friday, October 16, 2015, 4:15 - 6:15)
COMPARATIVE ALLOMETRY OF FEMORAL CURVATURE IN GORGONOPSIAN VERSUS THEROCEPHALIAN THERAPSIDS
BLOB, Richard W., Clemson University, Clemson, SC, United States of America, 29634; HUTTENLOCKER, Adam K., University of Utah, Salt Lake City, UT, United States of America; KAMMERER, Christian F., Museum für Naturkunde, Berlin, Germany; SIDOR, Christian A., University of Washington, Seattle, WA, United States of America
The limb bones of many tetrapods exhibit curvature along the diaphyseal long axis. This curvature can have consequences for the ability of these bones to bear loads. Because the greatest bending stress on limb bones is typically derived from forces acting transverse to the shaft, large tetrapods often walk with straighter, more upright legs to reduce bending by redirecting transverse forces up the long axis of the bone. However, if limb bones are curved, forces transferred up the long axis will act at a distance from the shaft centroid, imposing a bending moment arm due to curvature that can elevate bending stress. We previously evaluated how this curvature-induced moment arm changes with increasing body size in the femora of gorgonopsian therapsids, a lineage in which the femur often exhibits a distinctive, sigmoidal (S-shaped) curvature perpendicular to the plane of knee flexion/extension. We found a pattern of negative allometry, such that larger specimens typically had less curved (i.e., straighter) femora, potentially helping to reduce bending stress if more upright posture were used at larger size. How common is this morphological stress-reducing mechanism among other therapsids? In this study, we evaluated femoral curvature for a wide size range of specimens classified as therocephalians, representing taxa more closely related to mammals. As in our analysis of gorgonopsians, we measured the femoral moment arm due to curvature as the distance between the line of action of forces acting along the long axis of the bone (from one articular surface to the other), and the midpoint along the diameter of the bone at its midshaft. In contrast to gorgonopsians, this moment arm showed positive allometry relative to femoral length in therocephalians; in other words, large specimens showed relatively greater femoral curvature. Even if some of the smaller therocephalian specimens in our sample represent juveniles that did not have sufficient time for characteristic curvature to develop, the curvature-induced moment arm commonly exceeds 10% of femoral length in larger therocephalians, but approaches only 5% of femoral length in larger gorgonopsians. Although some of the largest, basal therocephalian taxa may show femoral straightening similar to large gorgonopsians, it appears that reduction of bone curvature is not a uniform mechanism for reducing locomotor stresses across therapsids, and that the use of upright limb posture may have required many therocephalians to accommodate increased bending from axial forces. Grant Information
Supported by NSF EAR-1337569.
Poster Session I (Wednesday, October 14, 2015, 4:15 - 6:15)
POSTCRANIAL MORPHOLOGY OF EARLY EOCENE CHOCTAWIUS GIVES NEW INSIGHT ON THE RELATIONSHIP OF MICROSYOPIDS TO OTHER EUARCHONTANS
BLOCH, Jonathan I., Florida Museum of Natural History, University of Florida, Gainesville, FL, United States of America, 32611; CHESTER, Stephen G., Brooklyn College, City University of New York, Brooklyn, NY, United States of America; HOLROYD, Patricia A., Museum of Paleontology, University of California, Berkeley, Berkeley, CA, United States of America
Evidence for understanding relationships of microsyopids to other euarchontan mammals (primates, treeshrews, and colugos), has been limited to craniodental data with postcranial bones not previously recognized even from localities where teeth are relatively common. Screen washing efforts at the late Wasatchian (Wa5; ~52 Ma) UCMP locality V70246 in the early Eocene Main Body of the Wasatch Formation near Bitter Creek station, Washakie Basin, south-central Wyoming, have yielded many dental and postcranial specimens of euarchontans including omomyids (Arapahovius, Anemorhysis), an adapid (Cantius), a paromomyid (Phenacolemur) and microsyopids including Microsyops and a small bodied uintasoricine here recognized as a new species of Choctawius previously know only from the early Eocene of Mississippi and New Mexico. Dental specimens of Choctawius n. sp. (n = 150) are the most common of the euarchontans, including the first lower dentitions for the genus showing that it had an enlarged procumbent incisor, a dental formula of 1:1:3:3 similar to that of Niptomomys, relative proportions of i1, p3, and p4 distinct from Niptomomys, and upper molars with a less developed anterior cingulum than other species of Choctawius. Isolated tarsal bones referable to Choctawius n. sp. include astragali (n = 5), calcanei (n = 5), and a cuboid (n = 1) based on size, abundance, and diagnostic similarities to dentally associated tarsals of euarchontans including astragali with an extension of the trochlea onto the neck and confluent sustentacular and navicular facets, and calcanei with an anteroposteriorly aligned ectal facet, a distally extended sustentacular facet onto the body, a round and concave cuboid facet, and the absence of a fibular facet. Choctawius is unique among Paleogene euarchontans in having an astragalar trochlea that extends as far distally as the dorsolateral margin of the navicular facet and an extremely large peroneal tubercle on the calcaneus. Although these tarsals differ from those of extant dermopterans in some ways (e.g., a less round astragalar head), they are similar in having an astragalus with an anteroposteriorly long flexor fibularis groove, a calcaneus with a deep excavation of the calcaneocuboid facet on the plantar side, and a corresponding proximal process on the cuboid. Choctawius had a very mobile ankle typical for euarchontan mammals and a deep cuboid pivot to strongly stabilize the calcaneocuboid joint as in colugos, suggesting that microsyopids might share a closer relationship to Dermoptera than previously appreciated.
