SamK Posted December 10, 2017 Share Posted December 10, 2017 Hi there, I'm new to the fossil forum, and was hoping I could get help in identifying this jaw. It was found in Marmarth, North Dakota in the Hell Creek Formation. I don't have any more specifics on location besides that. I hope the pictures are detailed enough, but if not, I can post more. I am thinking it has to be some kind of fish, but I am not completely sure. Any direction or help would be wonderful! Thank you so much! Link to comment Share on other sites More sharing options...
SamK Posted December 10, 2017 Author Share Posted December 10, 2017 Here are some more photos. Link to comment Share on other sites More sharing options...
Miocene_Mason Posted December 10, 2017 Share Posted December 10, 2017 Welcome to the forum from Maryland! Does look like a fish jaw, but I’m not skilled at these formations. Maybe @Troodon could be able to help? “...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin Happy hunting, Mason Link to comment Share on other sites More sharing options...
Troodon Posted December 10, 2017 Share Posted December 10, 2017 I believe what you have is a Champsosaurus jaw which is a diapsid reptile Link to comment Share on other sites More sharing options...
Miocene_Mason Posted December 10, 2017 Share Posted December 10, 2017 21 minutes ago, WhodamanHD said: Does look like a fish jaw Or I could be wrong “...whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved.” ~ Charles Darwin Happy hunting, Mason Link to comment Share on other sites More sharing options...
GeschWhat Posted December 10, 2017 Share Posted December 10, 2017 Welcome to the forum...looks like you were hunting in one of my favorite areas! Good poo picking up there. Lori www.areallycrappystory.com/fossils www.facebook.com/fossilpoo Link to comment Share on other sites More sharing options...
PFOOLEY Posted December 10, 2017 Share Posted December 10, 2017 Nice jaw...I think it is a fish. Search for the amiid Melvius ...there are some good references on the Forum to compare with. "I am glad I shall never be young without wild country to be young in. Of what avail are forty freedoms without a blank spot on the map?" ~Aldo Leopold (1887-1948) New Mexico Museum of Natural History Bulletins Link to comment Share on other sites More sharing options...
abyssunder Posted December 11, 2017 Share Posted December 11, 2017 Considering the biserial arrangement of the teeth and their diameter less than approx. 1mm , I think the fish hypothesis might be good. " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
jpc Posted December 11, 2017 Share Posted December 11, 2017 This one had me stumped, but I did look up a photo of a champsosaur jaw in Brinkman 2004, and I am with troodon... it looks very champsy. It is a good find. Link to comment Share on other sites More sharing options...
PFOOLEY Posted December 12, 2017 Share Posted December 12, 2017 @jpc, you made me reconsider my answer ... ...after looking at the pictures a bit more closely, I now see the double row of tooth sockets! I think this is a section of the jaw of a fish in the family Lepisosteidae...a gar! Something like this... image from arwsome.com ... Nice find, @SamK. "I am glad I shall never be young without wild country to be young in. Of what avail are forty freedoms without a blank spot on the map?" ~Aldo Leopold (1887-1948) New Mexico Museum of Natural History Bulletins Link to comment Share on other sites More sharing options...
SamK Posted December 12, 2017 Author Share Posted December 12, 2017 Thank you so much guys! I do see the double rows of sockets! I never noticed that before! Link to comment Share on other sites More sharing options...
jpc Posted December 12, 2017 Share Posted December 12, 2017 The only figure I am finding of a fossil gar (Estes, 1964) jaw shows an internal (lingual) row of large tooth sockets and an external (labial) row of much smaller teeth. I looked for a gar jaw in our collections and found no good ones. I still don't think it is a gar. The double rows on this fossil are too irregular to be gar. Having said that, I do not know what the configuration of alveoli is for champsosaurs. I found this photo of a modern gar jaw on the interwebs. http://dfwurbanwildlife.com/2013/02/24/uncategorized/spotted-gar-remains/ Link to comment Share on other sites More sharing options...
PFOOLEY Posted December 12, 2017 Share Posted December 12, 2017 Comparative and Developmental Functional Morphology of the Jaws of Living and Fossil Gars (Actinopterygii: Lepisosteidae) "I am glad I shall never be young without wild country to be young in. Of what avail are forty freedoms without a blank spot on the map?" ~Aldo Leopold (1887-1948) New Mexico Museum of Natural History Bulletins Link to comment Share on other sites More sharing options...
PFOOLEY Posted December 12, 2017 Share Posted December 12, 2017 4 hours ago, jpc said: ...fossil gar (Estes, 1964) jaw shows an internal (lingual) row of large tooth sockets and an external (labial) row of much smaller teeth... Good note...the search continues. "I am glad I shall never be young without wild country to be young in. Of what avail are forty freedoms without a blank spot on the map?" ~Aldo Leopold (1887-1948) New Mexico Museum of Natural History Bulletins Link to comment Share on other sites More sharing options...
KimTexan Posted December 12, 2017 Share Posted December 12, 2017 I know nothing about it, but it is a very cool find. In support of the reptile vs fish I will say that @JarrodB posted a jaw fragment of a Tylosaurus last week with a similar teeth pattern, with regards to the 2nd set of teeth. Clearly they’re different creatures and have no similarities otherwise. Link to comment Share on other sites More sharing options...
jpc Posted December 12, 2017 Share Posted December 12, 2017 There are some interesting tooth replacements going on in that Tylosaur post. Off center. I wonder if the jaw in question is a Parasaniwa... the local Monitor Lizard. Link to comment Share on other sites More sharing options...
abyssunder Posted December 12, 2017 Share Posted December 12, 2017 Is there any chance to know if the incomplete jaw is upper or lower? " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
Troodon Posted December 13, 2017 Share Posted December 13, 2017 I based my call on these images of Champs if you look at the very anterior tooth of the top jaw it looks similiar to the bases of the specimen in question. The density of teeth is similiar as well as size. Teeth and jaws are very similiar and even required a section in the Hell Creek guide on how to ID them. Link to comment Share on other sites More sharing options...
abyssunder Posted December 13, 2017 Share Posted December 13, 2017 That's why I was asking for. This document might be helpful, also, and is a really good. " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
darrow Posted December 13, 2017 Share Posted December 13, 2017 I think this is a Gar. I happened upon one decomposing recently and collected the mandible. I'll take some macro photos and post them shortly. Darrow Link to comment Share on other sites More sharing options...
jpc Posted December 13, 2017 Share Posted December 13, 2017 do gar teeth have those crenelated bases? Link to comment Share on other sites More sharing options...
darrow Posted December 13, 2017 Share Posted December 13, 2017 57 minutes ago, jpc said: do gar teeth have those crenelated bases? yes very much so. Link to comment Share on other sites More sharing options...
darrow Posted December 13, 2017 Share Posted December 13, 2017 Looks like the unidentified fish jaw may be a fragment from the rear/proximal end of the right mandible. For comparison, these are pictures of the same section of a modern Alligator Gar Atractosteus spatula, viewed from a similar angle. (sorry about the poor lighting) Darrow Link to comment Share on other sites More sharing options...
jpc Posted December 13, 2017 Share Posted December 13, 2017 Nice gar jaw. One thing I notice s that this gr has way more small teeth than the mystery jaw piece, and also where the modern teeth are missing, the crenelated tooth base is still there, whereas in the modern gar, the missing teeth have taken the crenelations with them. I am still thinking varanid... mosasaurs (close relatives) have crenelated bases even when there is no tooth. But that is a really nice gar jaw. Link to comment Share on other sites More sharing options...
jpc Posted December 13, 2017 Share Posted December 13, 2017 I am saying lower because it has hint of a palate. Our modern varanid skull is out teaching kids how to be a monitor lizard, so I can't look at it here and now, but I hope to soon. Link to comment Share on other sites More sharing options...
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