Sunday, March 10, 2019

Finishing up with Teeth, waiting for the Classification paper

I haven't posted much in the last 8 months as I haven't had much to post about. Most of the rocks have been taken apart and the bones extracted. The hard work of writing the classification paper is being done by Eric Metz at the University of Alaska, Fairbanks. He recently successfully defended his Masters Thesis which is the basis of the classification. I haven't seen it yet, and am anxiously waiting for it to be submitted for publication in the Journal of the Society for Vertebrate Paleontology (SVP). The companion paper, describing and classifying a smaller articulated (beautiful too) thalattosaur from Kake island, Alaska is also in the works.

I have been slowly working on the last of the "Bernie Blocks" at OMSI. There have been two toothy surprises recently. One is apparently the tooth of a Phytosaur. These animals closely resembled modern crocodiles through convergent evolution. They are common in New Mexico but this is the first evidence of them from Oregon.


Here is a reconstruction of what a Phytosaur may have looked like (courtesy of Dr Jeff Martin, NPS, Petrified Forest NM)


Here is what our tooth looked like (in life it's about 3cm long):
 

It is very nicely preserved with the original concavity at the root intact. I think it's a shed tooth. Maybe some of the other unknown bones we found may be Phytosaur scutes as well, though poorly preserved. 

In addition to the Phytosaur tooth, there is another jaw fragment with teeth. This one, funny enough, was set aside as it was broken lengthwise along a thin section so it looked exactly like a split rib. Since we've got lots of ribs, I didn't put a priority on working on it. But Surprise! it turned out to be a very important jaw fragment - Dr. Pat Druckenmiller at the UAF thinks it is a Dentary, the front end of the lower jaw! Since we didn't have that before, it's really great - and it's almost the last thing I'll ever prepare! Life sure likes a big joke once in a while. 

So now we're just waiting for the classification paper to come out. Then I will post clean scans of all the 180 scanned bones on Morphosource, and maybe Eric will post the digitally reconstructed skull as well.

I don't know what other studies will be done on this specimen in the future, but it's sure been a great time! G Carr