MikeDOTB Posted April 4, 2012 Share Posted April 4, 2012 Great trip report and assortment of finds! Sorry about all the vehicle trouble, I know it can be very frustrating! DO, or do not. There is no try. Link to comment Share on other sites More sharing options...
siteseer Posted April 4, 2012 Share Posted April 4, 2012 JP, Yes, that tooth. Pelagiarctos has been considered sort of a proto-walrus relative rather than a sea lion or seal. Even an isolated tooth is super-rare. I checked the original description a few minutes ago and it appears your tooth may be a first lower premolar of that animal (P. thomasi) as it follows the description of a tooth referred to the species. Jess Thanks all for the help on tooth IDs. Bobby- If you want I can take a few better pix for you. I assume we're all talking about the one I am calling a premolar. Is Pelagiarctos a seal of some sort? Link to comment Share on other sites More sharing options...
Boesse Posted April 4, 2012 Share Posted April 4, 2012 Pelagiarctos is some sort of an "imagotariine" walrus, along with Neotherium (from STH and other localities) and Imagotaria (from the younger Santa Margarita Sandstone). It was hypothesized to be a macrophagous predator, sort of a leopard seal analogue; however, the evidence for it is pretty weak and my colleague Morgan Churchill U. Wyoming, Clementz Lab) and I are reevaluating the taxon and its paleoecology. It is certainly larger than Neotherium, but not as large as Allodesmus. From Sharktooth Hill it is only known by the holotype "chin" (fused anterior part of dentaries) and a handful of teeth; several postcanines and a pair of canines were in the Ernst Collection, but god knows where that material is now. That basically represents nearly all of the world's known material of Pelagiarctos, except for the new (and more complete) material we're working with. Depending on where your specimen is going... it might be useful for us to include a description of it in our paper as a referred specimen. Bobby Link to comment Share on other sites More sharing options...
erik m Posted April 4, 2012 Share Posted April 4, 2012 Very nice report and lots of finds :Bananasaur: Link to comment Share on other sites More sharing options...
jpc Posted April 4, 2012 Author Share Posted April 4, 2012 (edited) Bobby... next time I get to Laramie, I'll show it to Morgan. Thanks for the update. If its that cool and important, I'll donate it to the Tate. And here I thought I had just another seal tooth. Edited April 4, 2012 by jpc Link to comment Share on other sites More sharing options...
Interpaleo Posted April 4, 2012 Share Posted April 4, 2012 Hello, just noticed this discussion, looked down at my pile of STH stuff to clean and saw what looks to be a similar tooth. This was also found at Slow Curve during last moths museum dig. I was wondering why it looked so different from my other seal molars, makes more sense now. What do you folks think? Same species or wishful thinking? Thanks, Joe Link to comment Share on other sites More sharing options...
Auspex Posted April 5, 2012 Share Posted April 5, 2012 My-oh-my... "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
DitchDiggerUno Posted April 5, 2012 Share Posted April 5, 2012 (edited) Is this one also? it came out of the same trench line that JP was digging. And awesome write up JP! -Joe P Edited April 5, 2012 by Ditch digger Link to comment Share on other sites More sharing options...
siteseer Posted April 5, 2012 Share Posted April 5, 2012 Joe, Auspex, I agree it that looks like a Pelagiarctos premolar as well. Suddenly, they seem not so rare. Jess Hello, just noticed this discussion, looked down at my pile of STH stuff to clean and saw what looks to be a similar tooth. This was also found at Slow Curve during last moths museum dig. I was wondering why it looked so different from my other seal molars, makes more sense now. What do you folks think? Same species or wishful thinking? Thanks, Joe Link to comment Share on other sites More sharing options...
siteseer Posted April 5, 2012 Share Posted April 5, 2012 That one doesn't seem to have the same ridge as the others but it may be one as well. Is this one also? it came out of the same trench line that JP was digging. And awesome write up JP! -Joe P Link to comment Share on other sites More sharing options...
Boesse Posted April 5, 2012 Share Posted April 5, 2012 Hey Guys, Joe - your tooth also looks like a Pelagiarctos p1 or P1 (lower case p = lower premolar, upper case P = upper premolar). Pelagiarctos teeth are characterized by having prominent anterior and posterior accessory cusps, a slight labial (cheek side) cingulum (ridge at base of crown with small projections), and a strongly crenulated lingual (tongue or medial side) cingulum, and retention of a metaconid cusp (which is not present here, but I don't think metaconids occur on P/p 1 teeth in pinnipeds or other arctoid carnivorans anyway). JP and Joe: if you guys are interested in donating these specimens, Morgan and I could certainly include descriptions of these specimens in our manuscript (which I plan on making headway with this long weekend, as the geo building here is closed the next 4 days for construction). If you guys are interested in having your specimens described, figured, and published (and relatively soon at that!), PM me. Ditch Digger: that tooth is from Allodesmus, which lacks cingulum (a ridge of enamel at the base of the crown) as well as anterior/posterior accessory cusps. That also is a posterior premolar or molar, and has fused root lobes: the p2-m1 of Pelagiarctos thomasi are all strongly double rooted. Allodesmus has only single rooted teeth (although some are slightly bilobate such as yours). Bobby Link to comment Share on other sites More sharing options...
DitchDiggerUno Posted April 5, 2012 Share Posted April 5, 2012 (edited) Sorry, I should have noticed the difference. Ditch Digger: that tooth is from Allodesmus, which lacks cingulum (a ridge of enamel at the base of the crown) as well as anterior/posterior accessory cusps. Edited April 5, 2012 by Ditch digger Link to comment Share on other sites More sharing options...
astron Posted April 5, 2012 Share Posted April 5, 2012 jp, Your trips and reports are always interesting but I think that this one is the top of the tops... Especially the whale scull is thrilling... Hopefully you are given a ''Thanks'' by Tate Congats on this superb topic with so nice and informative participations Astrinos P. Damianakis Link to comment Share on other sites More sharing options...
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