mississippi_ Posted July 29, 2014 Share Posted July 29, 2014 Hello all,In my first post on the fossil forum, I'd love some help with an ID of a tooth I found a few years ago at Frankstown, Mississippi, out of the Cretaceous coffee sands known for their abundance of Cretaceous marine fossils. I've found numerous shark, ray, fish, and mosasaur fossils at this location, but this one's got me stumped. I usually look to the Frankstown field guide (& the internet) to ID my finds, but I just can't seem to come to a satisfying conclusion about this one. Any help is greatly appreciated! Link to comment Share on other sites More sharing options...
vertman Posted July 29, 2014 Share Posted July 29, 2014 Absolutely beautiful tooth! Maybe a Protosphyraena? Link to comment Share on other sites More sharing options...
mississippi_ Posted July 29, 2014 Author Share Posted July 29, 2014 Definitely appears to be a Protosphyraena -- best ID so far! Link to comment Share on other sites More sharing options...
non-remanié Posted July 29, 2014 Share Posted July 29, 2014 (edited) I'd say Xiphactinus vetus. X. vetus teeth are more bladelike and recurved than the more commonly seen Xiphactinus audax. There have been many threads about X. audax/ X. vetus on the forum. More details and images can be found in those threads if you like. X. vetus is also a known faunal element of the Frankstown fauna, Protosphyraena is not, although it likely was around at the same time. Edited July 29, 2014 by non-remanié ---Wie Wasser schleift den Stein, wir steigen und fallen--- Link to comment Share on other sites More sharing options...
Ramo Posted July 29, 2014 Share Posted July 29, 2014 (edited) I think it is a little too thick for a Protosphyraena. Further, I don't think I have any proto teeth with the sunken in root section, but I have found Xiphactinus teeth (X. audax) with the bases like that. Ramo (those dang eastern fish confuse us western interior sea hunters. I found an enchodus tooth "back east" once that I still think looks weird) Edited July 29, 2014 by Ramo For one species to mourn the death of another is a new thing under the sun. -Aldo Leopold Link to comment Share on other sites More sharing options...
vertman Posted July 29, 2014 Share Posted July 29, 2014 Is this tooth too flattened to be a Xiphactinus? Aren't they pretty rounded off? Link to comment Share on other sites More sharing options...
non-remanié Posted July 29, 2014 Share Posted July 29, 2014 Not too flattened for X. vetus. I also think its too thick for Protosphyraena, as Ramo noted. ---Wie Wasser schleift den Stein, wir steigen und fallen--- Link to comment Share on other sites More sharing options...
mississippi_ Posted July 29, 2014 Author Share Posted July 29, 2014 Certainly appears to have characteristics of both... the tooth still appears to be more blade-like & thin than any X. vetus I've been able to compare it to, & it doesn't seem to be 'fluted' at all - the enamel surface is continuous from one edge to the other without any striations or noticeable texture, which is different than any examples of X. vetus teeth I've been able to find Link to comment Share on other sites More sharing options...
Xiphactinus Posted July 29, 2014 Share Posted July 29, 2014 I'll go with X. vetus too. Protosphyreana teeth are straight blades. They are thinner and don't curve in like the tooth in question. Link to comment Share on other sites More sharing options...
non-remanié Posted July 29, 2014 Share Posted July 29, 2014 (edited) To see the fluting on X. vetus I think you need a full tooth, and I think that it may also vary with jaw position, the same as the recurvature. I have 1 or 2 specimens very similar to your exact specimen from NJ and it is also hard for me to see any fluting on those specimens. But I think that those specimens are only partials and perhaps the fluting would be more apparent if more of the base of the tooth was preserved. As for the striations, they seem much more apparent on smaller X. vetus specimens. On my larger NJ specimens, I also see a lack of striations on at least some. Despite the ambiguity, I still think its definitely a lot closer to Xiphactinus vetus than Protosphyraena. Certainly appears to have characteristics of both... the tooth still appears to be more blade-like & thin than any X. vetus I've been able to compare it to, & it doesn't seem to be 'fluted' at all - the enamel surface is continuous from one edge to the other without any striations or noticeable texture, which is different than any examples of X. vetus teeth I've been able to find Edited July 29, 2014 by non-remanié ---Wie Wasser schleift den Stein, wir steigen und fallen--- Link to comment Share on other sites More sharing options...
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