Gray Fossil Site Symposium

This year is the 10th anniversary of the discovery of the Gray Fossil Site near Gray Tennessee. In honor of the event, East Tennessee State Natural History Museum and the Don Sundquist Center of Excellence in Paleontology co-hosted a one-day symposium on the current state of research at the site.

The seven talks in the morning session focused on geology, paleobotany and paleoclimatology at the site. Michael Whitelaw, Aaron Shunk, and Cynthia Liutkus looked at the basic underlying geology of the site (in an oversimplified form, Gray is basically a Cenozoic lake-sediment infill of karst/cave cavities in Paleozoic sediments). One interesting technique they used, which could have applications at Carmel Church, is to map the deposit by using gravity maps to determine the depth to the bedrock.

The rest of the morning talks described the vegetation, and used various techniques to try to get at paleotemperature, rainfall variation, canopy cover, and other ecological issues. The data here seems to be somewhat inconsistent, and the discussion became heated at times. Based on the presence of charcoal and the make-up of the plant communities (talks by Michael Zavada, and Diana Ochoa-Lozano and Yu-Sheng Liu) and isotopic ratios in the sediments (Yongli Gao, Taylor Burnham, and Michael Whitelaw, and Aaron Shunk) there are strong indications that there were drier periods and wetter periods at Gray, and at least some of these authors believe the climatic variations were seasonal. However, Larisa DeSantis and Steven Wallace presented (I think) very compelling isotopic data from herbivore tooth enamel that indicate that the Gray climate was seasonally very uniform, even though there could be longer-term variations. This seems a small point, but it results pretty significant differences in the ultimate interpretation of the paleoclimate.

Several talks (Yu-Sheng Liu with plants, DeSantis and Wallace based on isotope ratios in gomphothere teeth, and Steven Wallace in the afternoon session with red pandas) suggested that Gray may have been a relatively limited ecological refugium.

The afternoon was devoted to talks on vertebrates. Trying to identify fish remains from Gray, A. Brett Woodward discovered the same thing I’ve found working on Carmel Church fish – good fish skeletal references are practically nonexistent. He has been able to identify Micropterus (bass, like the one below left) and Lepomis (breems bream/sunfish below right):

Jim Mead and Blaine Schubert discussed the rare lizards from the site (a total of 12 bones). These remains included both skinks (below left) and glass lizards (below right):

Greg McDonald and Steven Wallace discussed the even more rare sloth remains (4 bones), apparently a megalonychid, and the timing of the arrival of sloths in North America (sloths migrated from South America long before the Isthmus of Panama formed). Blaine Schubert, Steven Wallace, and Leopoldo Soibelzon presented on the yet more rare (3 bones) tremarctine bear Plionarctos.

Steven Wallace’s talk, as mentioned above, was on the red panda Pristinailurus bristoli (below), for which a relatively large amount of material is now known:

The last four talks (by Richard Hulbert, Aaron Abernethy, Matthew Gibson, and Patrick Hawkins, with Steven Wallace as a co-author on all of them), were all on the Gray Site tapir Tapirus polkensis (top of page). Gray has the world’s largest collection of fossil tapirs, with at least 80 individual animals so far. Such a large sample from (apparently) a single species allows for population level studies that are normally impossible with fossil vertebrates, including individual variation and ontogenetic studies.

Congratulations to Gray Fossil Site on their tenth anniversary, and for the excellent and informative symposium.

This entry was posted in Conferences, Modern critters. Bookmark the permalink.

13 Responses to Gray Fossil Site Symposium

  1. Doug says:

    Oh how envious i am that you got to visit that place…

    “… suggested that Gray may have been a relatively limited ecological refugium.”- What does that mean? What’s ecological refugium?

    Yeah isn’t the panda known from like 70% of a skeleton?

  2. Anonymous says:

    I’d alter your entry from “bream” to “sunfish”, both common names but bream can be applied to about 15 different unrelated genera.

  3. Tom R. says:

    The anonymous Bream comment was mine. Keep up the good work on the blog

  4. Alton Dooley says:

    Thanks, Tom.

    The bream vs. sunfish discussion actually took place during the meeting! To those of us that work on marine critters (and apparently to most of the people at the meeting), sunfish always means ocean sunfish (Family Molidae), rather than the unrelated Family Centrarchidae (freshwater sunfish). Since I talk about molids a fair amount on the blog, I used bream to avoid confusion here.

    Even so, I modified it text to include both (and corrected my misspelling of bream).

  5. Alton Dooley says:

    Doug, a refugium is an area that contains a relict population, typically resulting from climate change. When the climate changes in a particular area, some places will change more rapidly than others. Organisms adapted to the earlier climate will tend to persist longer in the places where the climate changes later (it provides a refuge, hence the name).

    The suggestion with Gray is that it served as a refugium for an ecosystem based on C3 plants when most of the surrounding areas were transitioning to C4 plant ecosystems.

    They do indeed have a lot of the red panda, probably more like 80%. They’re only missing the posterior ribs, and some bits and pieces from the pelvic girdle and hind limbs.

  6. Lisa Stoner says:

    You are right about the symposium. The talks were very informative and enjoyable. Hopefully, with all of the ongoing research, they will continue to host a symposium every year. BTW, Alton, I don’t know if you got to meet him (or you may already know him), but Larry Bristol, the gentleman for whom the red panda (Pristinailurus bristoli ) was named, was at Friday night’s reception.

  7. Alton Dooley says:

    Unfortunately I didn’t get to meet Mr. Bristol; I arrived late Friday night.

    I also hope to see future Gray symposiums, as well as a major presence at SeAVP. There’s certainly enough material there to produce interesting findings for years to come.

  8. Doug says:

    Hey Alton,
    The banner for the museum says it’s in association with the Smithsonian Institute. What does that mean? How does it affect the museum?

  9. Alton Dooley says:

    We pay a fee to the Smithsonian (I think we have to meet certain collections standards first), and get various perks in return, like streamlined loans, ability to offer some Smithsonian perks to our members, and the ability to put their name on our logo (which helps with donations); I’m not sure of all the details of the agreement. It enables smaller museums like us to benefit from the Smithsonian’s name.

    We’re developing a similar affiliate program to allow even smaller museums to become VMNH affiliates.

  10. boesse says:

    I remember having a journal club meeting during my sophomore year of college when they first described the red panda from two upper postcanine teeth, which upset some of our grad students (who work on dinosaurs, which have morphologically more plastic and homoplastic teeth).
    A year and a half later (Ottawa SVP meeting) a poster presentation showed that they had several more bones, including a complete lower jaw, which only corroborated their identification of it as an ailurid. Now, to see nearly complete cranial material – well, that’s just awesome.

  11. Alton Dooley says:

    If I’m not mistaken, Steven Wallace took a little flack over that initial description (not questioning whether it was an ailurid, but its position within the family). That was all they had found at the time, but the more complete material found later confirmed everything they said in the initial description. (If you’re reading this, Wally, and I got any of it wrong, please correct me.)

  12. Brett says:

    Great synopsis, Alton! Good to see you at the symposium as well. About the panda: we’re still actively finding bits and pieces of that specimen. It was actually found in the spoil piles that were removed for the current museum building. We have isolated the spoil pile (known as the “panda pile”) and we are sifting through every bit of it and we are still finding elements of the specimen. So, that 80% of the skeleton is growing!

  13. Alton Dooley says:

    I’ve noticed that every time I visit Gray, y’all seem to have a little more of the panda!

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s