Jared C Posted September 7, 2021 Share Posted September 7, 2021 An assortment of interesting finds from our hunt today. This was in the late cretaceous Ozan formation (also called the Lower Taylor Marl, I believe) around the Austin area, in central Texas. I'd like confirmation or correction on some ID's 1) I'm thinking Mosasaur tooth for this one, but since it's small enough to maybe be fish, I'm checking anyway. If measurements end up being important for any of these, I can provide them. 2.) I'm thinking Cretolamna for this shark tooth, but it looks like the cusps have two peaks, which is throwing me off. Any thoughts? 3.) A very unusual ptychodus. It looks like there was a dome that was worn flat, but that would imply then that this is a Ptychodus whipplei, which is supposedly quite unlikely around Austin. @LSCHNELLE, any thoughts? 4.) I'm fairly positive on this one being some species of Cretolamna, but since I've never seen Cretolamna in this area before, I'm just making doubly sure. This one is about the size of a finger nail. “Not only is the universe stranger than we think, it is stranger than we can think” -Werner Heisenberg Link to comment Share on other sites More sharing options...
ThePhysicist Posted September 7, 2021 Share Posted September 7, 2021 1 hour ago, Jared C said: I'm thinking Mosasaur tooth for this one, but since it's small enough to maybe be fish, I'm checking anyway. If measurements end up being important for any of these, I can provide them. Hmm, I lean fish. It's more compressed than most mosasaur teeth, and it's fairly skinny for its height. Can we also see the cutting edges face-on? They should be prominent and extend virtually the whole length of the crown. ^https://www.jstor.org/stable/4523841?seq=6#metadata_info_tab_contents 1 hour ago, Jared C said: 2.) I'm thinking Cretolamna for this shark tooth, but it looks like the cusps have two peaks, which is throwing me off. Any thoughts? Goblin shark - Cretolamna doesn't have a "nutrient groove" in the root. 1 hour ago, Jared C said: 3.) A very unusual ptychodus. It looks like there was a dome that was worn flat, but that would imply then that this is a Ptychodus whipplei, which is supposedly quite unlikely around Austin. @LSCHNELLE, any thoughts? It's probably P. whipplei, seeing how prominent the cusp is compared to the "base" / foot of the crown. The ridges are also gone by the time they reach the base. 1 hour ago, Jared C said: 4.) I'm fairly positive on this one being some species of Cretolamna, but since I've never seen Cretolamna in this area before, I'm just making doubly sure. This one is about the size of a finger nail. Yes, C. appendiculata. "Argumentation cannot suffice for the discovery of new work, since the subtlety of Nature is greater many times than the subtlety of argument." - Carl Sagan "I was born not knowing and have had only a little time to change that here and there." - Richard Feynman Collections: Hell Creek Microsite | Hell Creek/Lance | Dinosaurs | Sharks | Squamates | Post Oak Creek | North Sulphur River | Lee Creek | Aguja | Permian | Devonian | Triassic | Harding Sandstone Instagram: @thephysicist_tff Link to comment Share on other sites More sharing options...
Jared C Posted September 7, 2021 Author Share Posted September 7, 2021 10 minutes ago, ThePhysicist said: Hmm, I lean fish. It's more compressed than most mosasaur teeth, and it's fairly skinny for its height. Can we also see the cutting edges face-on? They should be prominent and extend virtually the whole length of the crown. ^https://www.jstor.org/stable/4523841?seq=6#metadata_info_tab_contents Goblin shark - Cretolamna doesn't have a "nutrient groove" in the root. It's probably P. whipplei, seeing how prominent the cusp is compared to the "base" / foot of the crown. The ridges are also gone by the time they reach the base. Yes, C. appendiculata. Fantastic answer yet again @ThePhysicist, thank you! Looking closely again at the "mosasaur" tooth, I realize that there aren't actually any cutting edges. What I originally assumed was a cutting edge is actually just a split in the enamel. I completely understand it being fish now. This may be a stretch, but any idea what fish it could be? I feel fairly comfortable ruling out Enchodus, but it seems to have some resemblance to Pachyrhizodus or Xiphactinus. I can send more photos if that still helps Also, I've never heard of Goblin shark teeth having cusps. I'm by no means knowledgeable on the subject though. The teeth I'm used to seeing from goblins are from Scapanorynchus texanus, with long, thin blades and no cusps. Is this tooth from a different goblin shark species? If it isn't, then is it just a tooth one would find further along the back of the mouth in a S. texanus ? “Not only is the universe stranger than we think, it is stranger than we can think” -Werner Heisenberg Link to comment Share on other sites More sharing options...
Thomas.Dodson Posted September 7, 2021 Share Posted September 7, 2021 1 hour ago, Jared C said: The teeth I'm used to seeing from goblins are from Scapanorynchus texanus, with long, thin blades and no cusps. Is this tooth from a different goblin shark species? If it isn't, then is it just a tooth one would find further along the back of the mouth in a S. texanus ? As you guessed you're describing anterior teeth. Lateral Scapanorynchus texanus teeth do have definitive cusps. Anterior teeth will sometimes be cusped as well but they're very reduced when present. Link to comment Share on other sites More sharing options...
Al Dente Posted September 7, 2021 Share Posted September 7, 2021 2 hours ago, Jared C said: Also, I've never heard of Goblin shark teeth having cusps. I'm by no means knowledgeable on the subject though. The teeth I'm used to seeing from goblins are from Scapanorynchus texanus, with long, thin blades and no cusps. www.elasmo.com has an example of a S. texanus dentition. Link to comment Share on other sites More sharing options...
Gareth_ Posted September 7, 2021 Share Posted September 7, 2021 (edited) 6 hours ago, Jared C said: 2.) I'm thinking Cretolamna for this shark tooth, but it looks like the cusps have two peaks, which is throwing me off. Any thoughts? For what it's worth, one of my Cretalamna teeth have 2 cusps on either side of the crown. Some of my O. obliquus teeth do too but the second cusp is far less pronounced Some nice finds though! Edited September 7, 2021 by Gareth_ 1 Link to comment Share on other sites More sharing options...
JohnJ Posted September 7, 2021 Share Posted September 7, 2021 I would look closer at Ptychodus mortoni. The geology is a better match than P. whipplei. 2 The human mind has the ability to believe anything is true. - JJ Link to comment Share on other sites More sharing options...
LSCHNELLE Posted September 7, 2021 Share Posted September 7, 2021 (edited) JohnJ is correct about P. mortoni being a better match. Unless reworked, P. whipplei would not be present above the Atco Member of the Austin Group. Your Ptychodus appears to be a little worn or digested. So, the lower ridges may have some dimpled patterns showing from below the original enamel. Shawn Hamm says that P. mortoni has 12 different forms (heterogeneity). And, I think this could readily be one of them. The granular texture around the margin area would also be a match. With the crown worn off, IDs are much more difficult. P. rugosus is very rare, but could also be a long shot. Yet, the crown is usually offset at a significant angle from the posterior side on P. rugosus laterals. This one is not offset much. Bottom line, I can't say for certain. Edited September 8, 2021 by LSCHNELLE Added source. 4 Link to comment Share on other sites More sharing options...
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