Jared C Posted October 26, 2021 Share Posted October 26, 2021 Hey y'all, here are two finds from two different trips that I'm having trouble IDing 1.) This Ptychodus from the sprinkle formation ( a tongue of the Ozan here in central Texas). I'm not sure, but I think the sprinkle formation around here is Santonian in age (~86-83 myo). (Please chip in if you actually know - google is so vague here) I have a suspicion, but I don't want to count my eggs before they hatch for this one. Any ideas? 2.) What I suspect might be a Cretoxyrhina mantelli (not sure if I see evidence of broken cusps or not, so I included many photos to help show that), from what I believe might be a permanent Eagle Ford exposure here in Williamson County, central texas (exciting stuff!). The blade seems a bit thin. Any ideas? 2 1 “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...
Jared C Posted October 26, 2021 Author Share Posted October 26, 2021 @ThePhysicist @LSCHNELLE “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 October 27, 2021 Share Posted October 27, 2021 I can confidently ID maybe 3 Ptychodus species, and this isn't one of them. Perhaps P. anonymus? Good ginsu - one of my favorites. 1 "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 October 29, 2021 Author Share Posted October 29, 2021 (edited) @siteseer @Thomas.Dodson any ideas on this Ptychodus? It kind of reminds me of P. decurrens, but I believe P. decurrens may be too old. Part of me suspects P. martini , but that supposedly would be rare for central texas Edited October 29, 2021 by Jared C “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 October 29, 2021 Share Posted October 29, 2021 On 10/26/2021 at 2:10 AM, Jared C said: 1.) This Ptychodus from the sprinkle formation ( a tongue of the Ozan here in central Texas). I'm not sure, but I think the sprinkle formation around here is Santonian in age (~86-83 myo). (Please chip in if you actually know - google is so vague here 14 minutes ago, Jared C said: @siteseer @Thomas.Dodson any ideas on this Ptychodus? It kind of reminds me of P. decurrens, but I believe P. decurrens may be too old. Part of me suspects P. martini , but that supposedly would be rare for central texas The Collector's Guide to Fossil Sharks and Rays from the Cretaceous of Texas lists the Sprinkle in the Austin area as Middle Campanian. Even putting age aside, I don't see Ptychodus decurrens. With that said, I'm not confident what it is so I'd like to hear what others have to say. Taking both age and characters into account I'd guess a posterior P. latissimus. P anonymus seems possible but the transverse ridges are rather strong for it and the teeth are supposed to be small. How big is this tooth? Link to comment Share on other sites More sharing options...
Jared C Posted October 29, 2021 Author Share Posted October 29, 2021 18 minutes ago, Thomas.Dodson said: How big is this tooth? It is rather small - it's maximum length is in the neighborhood of 3/4 of an inch (about 2 cm I believe) 19 minutes ago, Thomas.Dodson said: Taking both age and characters into account I'd guess a posterior P. latissimus. P anonymus seems possible but the transverse ridges are rather strong for it and the teeth are supposed to be small Here's a graphic posted on the Ptychodus ID guide about Ptychodus species age's. I think @LSCHNELLE, the member who posted it, made it off of Shawn Hamm's estimates. It looks like most Ptychodus lineages are extinct by the Campanian? Does that mean these teeth are rather eroding out of a layer below the sprinkle formation? Also, what suggest P. anonymus? My impression is that P. anonymus were high crowned. Sorry for all the questions “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 October 29, 2021 Share Posted October 29, 2021 22 minutes ago, Jared C said: It is rather small - it's maximum length is in the neighborhood of 3/4 of an inch (about 2 cm I believe) Here's a graphic posted on the Ptychodus ID guide about Ptychodus species age's. I think @LSCHNELLE, the member who posted it, made it off of Shawn Hamm's estimates. It looks like most Ptychodus lineages are extinct by the Campanian? Does that mean these teeth are rather eroding out of a layer below the sprinkle formation? Also, what suggest P. anonymus? My impression is that P. anonymus were high crowned. Sorry for all the questions Maximum listed for P. anonymus is 14 mm in Collector's Guide to Fossil Sharks and Rays from the Cretaceous of Texas. You're correct that P. anonymus is a bit higher crowned and that's part of the reason I expected P. latissimus instead although yours seems somewhere in-between the two in crown height. The Collector's Guide lists the diagnostic characters for P. anonymus as small tooth size, fine transverse ridges (your specimen seems more coarse), weakly conical high cusp, and the gentle transition between the transverse ridges and the granular margin area. All I can say about the age question is that the Collector's Guide lists two species from the Campanian; P. connellyi and P. latissimus. Here's the stratigraphy figure if you wanted to check the cited sources. I'm not familiar with Shawn Hamm's literature. Link to comment Share on other sites More sharing options...
Jared C Posted October 29, 2021 Author Share Posted October 29, 2021 This was really useful- I think I ought to buy this guide now! Thanks for you answer “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...
LSCHNELLE Posted October 30, 2021 Share Posted October 30, 2021 (edited) The New Mexico Museum of Natural History Bulletin 81 is much more up-to-date than the Collector's Guide.... The only known Ptychodus species that appears in the Campanian is in Alabama and England is P. polygyrus. Almost all teeth from the Ozan Formation are reworked from older Santonian deposits and maybe Coniacian. Per Bulletin 81, this would most likely be a lateral or posterior file P. martini or a much older reworked P. latissimus from the Coniacian. I am guessing the first one. Edited October 30, 2021 by LSCHNELLE Link to comment Share on other sites More sharing options...
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