Fifth SeAVP Meeting

Last Friday, the fifth annual meeting of the Southeastern Association of Vertebrate Paleontology (SeAVP) was held at Appalachian State University in Boone, NC. I always enjoy these meetings, in part because there is only one technical session, so I get to hear all the talks.

The morning session was devoted to non-mammalian vertebrates (what used to be called “lower vertebrates” in old SVP programs). The day started with Nathaniel Fox reporting on Triassic ichnofossils from the Hartford Basin in Holyoke, MA, such as the example above from Dinosaur State Park, which is also in the Hartford Basin.

Next was Vince Schneider, with Andy Heckert and Nick Fraser, on aetosaurs from the Triassic Deep River Basin in North Carolina. Aetosaurs were armored archosaurs that are known only from the Triassic, and at least four genera are now known from the Deep River Basin, including Typothorax (Typothorax cast below is from New Mexico, and is on exhibit at the New Mexico Museum of Natural History and Science):

 

The Triassic talks continued with Andy Heckert, Vince Schneider, Jonathan Mitchell and Eric Sload reporting on tiny teeth from lungfish and hybodont sharks from Deep Creek Basin.

Moving into the Jurassic, Christina Byrd (who worked at Carmel Church as an undergraduate) discussed ontogenetic changes in the scapula of polycotylid plesiosaurs (example below from the Wyoming Dinosaur Center):

 

The last Mesozoic talk was by WIlliam Garcia and Scott Hippensteel, on the taphonomy of a Cretaceous marine deposit near Elizabethtown, North Carolina.

Jim Mead and Blaine Schubert reported on specimens of the snake Pterygoboa from the Miocene of Florida, and reviewed Pterygoboa‘s rather intricate vertebral anatomy.

The next two talks were on turtles. Steven Jasinski discussed the shell anatomy of slider turtles of the genus Trachemys from the Gray Fossil Site in Tennessee (modern Trachemys below from the Jacksonville Zoo), followed by David Moscato and Steven Jasinski again on Pleistocene turtles from Sonora, Mexico.

 

Leigha King and Blaine Schubert looked at cranial pitting in the skull of Alligator (visible in the U. S. National Museum specimen below), and specifically whether the pitting changes during ontogeny (it does).

 

After lunch the talks shifted to mammals. Rachel Short compared specimens of the rhinoceros Teleoceras from Gray Fossil Site to species from other localities. It appears that various body proportions may be different in Teleoceras from different localities (T. hicksi, below, from Gray Fossil Site). Incidentally, Rachel had lost her voice, so her presentation was given (very well) by Laura Gilmore.

Laura presented her own research (with Steven Wallace) in the next talk, about Pliocene raccoons from Florida, and specifically on size and shape variation (some of the Florida specimens are really big compared to modern raccoons).

Eric Lynch spoke on the always contentious issue of limb posture in the giant short-faced bear, Arctodus simus, proposing that there are characteristics in Arctodus posture that indicate it could have been a better runner than other bears.

Brian Beatty and Matt Mihlbachler have been doing a lot of work in recent years on tooth wear in various animals. Their talk looked at mesowear patterns in camel teeth from North America. As with horses, camels teeth show an increase in wear starting in the Miocene, when North America began getting cooler and drier.

Lindsey Yann (another Carmel Church veteran) and Larisa DeSantis have been using stable carbon and oxygen isotopes to look at shifts in diet preferences in Pleistocene mammals from Florida. They suggest that diversity tended to increase during interglacial periods due to an increase in dietary niches.

Richard Hulbert addressed the thorny issue of Pleistocene horse taxonomy, specifically, how many species were there? At least in the southeastern US, he found no evidence for more than one species when examining tooth dimensions (the Equus molar below is from Saltville, VA, in the VMNH collection).

 

The last talk of the day was by Ryan Haupt and Larisa DeSantis, on microwear patterns in xenarthran teeth (modern xenarthrans include armadillos, sloths, and anteaters). This is trickier than it sounds; one of the characteristics of xenarthrans is that their teeth don’t have enamel, so the microwear scratches are in the dentin. Their study suggests that it might be possible to use the dentin microwear, but that enamel microwear will probably not be a good model to use in interpreting it.

There were also nine poster presentations. Gary Stringer, Roger Lambert, and George Phillips compared bulk collecting to surface collecting techniques for recovering fish otoliths. Logan Howell, Katie Estridge, and Andy Heckert reported on the frequency of dinosaur paleopathologies in the published literature.

Brian Beatty is trying to describe the heterodonty present in toothed whales. While many general texts describe dolphins and other odontocetes as being homodont (meaning all the teeth look the same), in fact odontocetes are almost always heterodont to some degree. In some cases,  such as Squalodon (below, from the U. S. National Museum), the heterodonty is obvious, while in other taxa it is more subtle.

 

Lucas Loffredo and Larisa DeSantis did a poster on mesowear methodology, checking the viability of mesowear scoring methods and their correlation to isotope data. They found that the mesowear score depends a great deal on who does the scoring, and that the mesowear scores and isotope values don’t correlate well (although this isn’t necessarily surprising, as diet is only one variable in mesowear).

Shelly Donohue and Larisa DeSantis began building a tooth microwear baseline for modern bears with known diets, which can be used in studies of fossil bears to help infer their diets.

Daniel Williams looked at Pleistocene white-tailed deer and found that they were smaller than their modern counterparts, except modern populations that are under some stress. He suggests that the small size of the Pleistocene specimens could be due to competition with larger Pleistocene browsers such as camels, tapirs, and mastodonts.

Jessica Miller-Camp examined supposed sexual dimorphism in the Triassic dicynodont Lystrosaurus (skull below at the Wyoming Dinosaur Center). She found that at least some of the data indicating sexual dimorphism in this taxon is not very strong.

 

Nick Lashinsky and Larisa DeSantis examined the stable isotope signatures of modern forest wallabies and tree kangaroos (such as Dendrolagus, below, from the San Diego Zoo), to establish a baseline for studies on fossil marsupials.

I presented my poster with Nancy Moncrief on porphyria in fossil and sub fossil eastern fox squirrels.

This was yet another pleasant and successful meeting of SeAVP, and I’d like to thank Andy Heckert and the Geology Department at Appalachian State University for organizing and hosting the meeting.

 

 

 

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