Monday, April 13, 2009

Fossil of the week 4/13/09

For our inaugural installment I present to you RMDRC 08-002, a Tylosaurus nepaeolicus specimen that was discovered in May of 2008 by John Bennitt in Gove County, KS. Lower jaw length is 757mm, for those of you keeping score. This was found on a private ranch where our company has been scouting for nearly 25 years. Because the Niobrara Chalk erodes so readily, the entire outcrop must be scouted every 2-5 years. In fact, this specimen was discovered less than 100 feet from a tiny Clidastes skull that I found 2 seasons prior.

Since this is an articulated specimen, not much else will be done to it. Taking it apart for a 3-D mount risks too much damage to the skull, and articulated chalk specimens tend to have a lot of distortion from being smashed flat. In any case, there are plenty of cool things about this critter that re already shown. If you look closely at the neural spines of the anterior dorsal vertebrae, you'll notice a nice arc of missing bone. Click on the image for a larger view if jacket 1 of 3. This is a bite mark attributed to the shark Cretoxyrhina mantelli, whose shed teeth were also found lodged in Tracie. There appears to be a little preserved skin in both the left dorsal and lateral temporal openings, and the sclerotic ring of the eye is still in place. The cervical, dorsal and pygal vertebral series are complete, however the limbs and much of the tail appear to have been forcibly removed from the animal, hopefully after it died. This specimen is currently off exhibit due to Darwin and Dinosaurs, however it will return on display in July.


  1. Neat specimen... Mosasaurs curled up in a circle like that have been described since Cope in the early 1870s... probably rather easy to do once the sharks have stripped everything away from the skull and vertebrae....

  2. Sharks certainly do a number on mosasaur carcasses. This one in particular was chomped on by at least 2 different genera.