Friday, May 17, 2013

More Mosasaur Fun, Complete With Spectators

Just finished a sort of long-term new project for us. Occasionally we get requests from museums and universities to come out in the field with us and collect specimens. Even more occasionally, we oblige. In 2011 a class from the University of Tennessee - Martin (actually 2 classes, one in geology, one in journalism) came out to our digsites in western Kansas to find and document fossils for a new museum project. TPI fieldcrews supervised and instructed, however we let the students do the finding. They came up with several neat little fossils (several Spinaptychus, a Chelosphargus partial skull, Martinichthys skulls) and lots of partial fish. On the second day, one student hit the jackpot: the tip of the lower jaw of a mosasaur poking out from just under the alluvium. 

Ever feel like you're being watched?

Here, Aaron (the discoverer) works to remove overburden from the specimen. TPI does the same thing, though usually with fewer spectators. He decided to name the mosasaur "Kimberly". I've named specimens worse things I suppose.
Digsite viewed from across the gully, right near MU 5
 The specimen was tentatively identified int he field as Platecarpus planifrons. Though reasonably well articulated, it was missing the front limbs and everything back behind the mid dorsal vertebrae. UTM students preimetered, stabilized and jacketed the specimen. Most importantly they also carried the slab across the badlands to the nearest truck, which was great for me!

Standard TPI field photo pose, before jacketing
Back in the lab, preperation was begun by UTM students under TPI guidance. Mosasaurs are usually pretty straightforward to work with, however this one presented a few challenges. The proximity to the alluvium meant that this specimen encountered some weathering back during the last ice age, and roots made matters worse. The prognosis was grim initially, as the bone and teeth looked to be in pretty rough shape. But careful consolidation and prep resulted in not only stable bone, but the discovery of the preserved remnants of tracheal rings, as well as extracollumnellar (ear) cartilage. At the rear of the left lower jaw, one of the scavenging sharks, Squalicorax falcatus, left its calling card.

Kimberly's skull
Next up the specimen will be delivered to the new museum in Tennessee, where it will go on display later this year. Luckily the whole process was documented by the journalism students, almost from the instant of discovery. If I see the video, I'll post a copy on the blog in the future.

Not a bad little mosasaur.

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