David Schwimmer, William Frazier, and William Montane reported on fossil-rich silicious concretions from the Cambrian of Georgia. Trilobites are common in these concretions, including Elrathia (above, although this example from the Wyoming Dinosaur Center was found in Utah). Some of the most common fossils are sponges, which also appear to be the source of the silica in the concretions.
Andy Heckert, Vince Schneider, Jonathan Mitchell, Eric Sload, and Paul Olsen reported on the vertebrate fossils from the Deep River Triassic basin in North Carolina. In addition to larger specimens such as aetosaurs, metoposaurs, and phytosaurs (such as the example below, on exhibit at the American Museum of Natural History), they have been very successful at screening for micro vertebrates, which has greatly increased the known fauna for that basin.
Amanda Giesler, Blaine Schubert, and Larisa DeSantis discussed cervid (deer) remains from Late Pleistocene deposits from Guy Wilson Cave in Tennessee, which included Odocoileus (white-tailed deer, below), Rangifer (caribou), and either Cervalces or Alces (stag moose or moose). Isotopic studies suggest that the deer were living in a forested environment, eating similar types of plants to what they do now.
In the afternoon was an entire session on conservation paleobiology, using the fossil record to provide data for conservation efforts. Tony Martin (@Ichnologist on Twitter) live-tweeted the entire session under the hashtag #ConservPaleobio2012 (except for his own talk, which I tweeted). His talk discussed the usefulness of traces in understanding the prominence and effects of invasive species on Georgia’s barrier islands, specifically feral horses, cattle, and hogs.
Rowan Lockwood described the results of a project to determine the utility of the fossil and sub-fossil record of Chesapeake Bay mollusks in establishing a baseline for past changes in the Bay’s ecology. While the ancient molluscan fauna provides a good model for determining past faunal makeup on a broad scale, the time resolution of the sediments is not good enough to reliably detect small-duration events (decades or centuries).
Larisa DeSantis looked at carbon isotope values in Pleistocene mammals from Florida and Australia, to look for shifts in rainfall and preferred vegetation over time. These changes are very detectable in the stable carbon data, but one of the most interesting results was that there were not wholesale faunal replacements as the rainfall and vegetation shifted. Instead, many of the animals simply changed what they were eating. I can’t say this comes as a surprise (animals are notorious for not doing what they’re “supposed” to do), but it’s nice to see it confirmed in their tooth enamel isotopic ratios.
There were lots of other interesting talks and posters at the meeting, and unfortunately I can’t cover them all here, as I need to get some rest before my drive home tomorrow. As with my previous experiences, SE-GSA has been a pleasant and educational meeting.
I’m going to take a bit of much-needed vacation time over the next week, but I still hope to get a few blog posts written over that time.