Cretaceous Jaws out of the Niobrara, Logan Co. KS

[chg057]

Hello TFF,

I recently was able to glue this specimen together after its discovery this past fall. I need help with identification.

It was found in the Niobrara in Logan Co, Kansas. After asking a tooth expert, he hypothesized that it is a Hesperornis. I've done a little research myself and I am not convinced of his conclusion. Of the Hesperornis pictures I've seen online, it appears that the top jaw lacks teeth at this part of the jaw, whereas my specimen is full of teeth.

Additionally, there are two rows of distinctly different teeth on both the lower and upper jaw. One set is larger, more spaced teeth approximately 3mm apart and up to 4mm wide at the base. The larger teeth have all broken slightly and look like little volcanoes protruding from the jaw.

The second row of teeth in the same jaw contains much finer and closely spaced teeth - about 0.5mm apart, 1-1.5mm wide, and about 2-3mm long. The two rows of teeth are slightly angled from each other - about 20 degrees or so.

Any suggestions?

I got a second opinion: Cimolichthyes...? What do you all think?

Thanks for your help!

Edited March 10, 2016 by chg057

[JohnJ]

Looks just like the ones on Oceans of Kansas.

[chg057]

Looks just like the ones on Oceans of Kansas.

You're right! Thanks JohnJ!

[jpc]

certainly NOT Hesperornis. For exactly the reasons you mention.

[Auspex]

certainly NOT Hesperornis. For exactly the reasons you mention.

[KansasFossilHunter]

Are these the ones you asked Dr.Wilson about?

[jpc]

I hope Dr. Wilson would not call this a Hesperornis. She knows her Cretaceous birds.

[KansasFossilHunter]

She absolutely does know her bird material. If this is the one that was sent to her, we decided on Cimolichthys as well.

[chg057]

Yes this is the same one sent to Dr. Wilson. Thanks for the help!