[Group A] Crocodile, Alligator, Mosasaur… Tooth ID

[Spr]

Found on the shores of Holden Beach, North Carolina. If you need measurements of anything let me know, thanks.

[Jared C]

Do you know the age (or name) of the strata in the area? That would be very helpful to begin ruling out options

[hemipristis]

1 hour ago, Jared C said:

Do you know the age (or name) of the strata in the area? That would be very helpful to begin ruling out options

Holden Beach is a Pleistocene barrier island with a Pliocene core that is comprised overwhelmingly of quartzose sands mixed with a bit of whatever flows out of the rivers on either end of the island.  The area on the other side of the sound on the mainland is underlain by the Pliocene Waccamaw Formation, a very shelly Pliocene unit, and the stratigraphic equivalent of the famous Yorktown Fm that produces so many beautiful fossils in northern NC and Virginia.  Further inland are fossiliferous Cretaceous Peedee sediments.  The two rivers that ultimately discharge into the ocean at the two inlets on either end of Holden Beach meander through both strata.  The Peedee is known for vertebrate fossils, while the Waccamaw is not.  I highly suspect that these are Peedee (Cretaceous) teeth.

 

If I remember a recent thread on Greens Mill Run teeth (which may also be Peedee sediments, I cannot recall), ovate cross-sections with flat "facets" on the blade indicate mosasaur.  Reptile experts, please correct me if I'm off about this.

 

 

[pachy-pleuro-whatnot-odon]

1 hour ago, hemipristis said:

If I remember a recent thread on Greens Mill Run teeth (which may also be Peedee sediments, I cannot recall), ovate cross-sections with flat "facets" on the blade indicate mosasaur.  Reptile experts, please correct me if I'm off about this.

 

Yup, these three teeth are indeed mosasaur teeth. Prismatism of the first tooth from left and, if I'm not mistaken, slight mediodistal curvature and unequal cross-section suggest this tooth can likely be attributed to the genus Mosasaurus. The middle tooth may also be Mosasaurus for it's prismatic look, though it lacks the unequal cross-section and labiolingual curvature. Instead, it has much more of a distal curvature, yet the fact that the curvature runs the full height of the tooth and isn't restricted to the upper third as well as lack of tertiary striae rule out a tylosaurine origin. As such, I propose this may be a palatine Mosasaurus-tooth. The last tooth on the right looks again to be a more regular Mosasaurus tooth, as it seems to me it has a subequal cross-section and mediodistal curvature. As it, moreover, lacks clear prismatism and faceting, there's a good chance of this tooth being attributable to M. cf. Mosasaurus hoffmannii.

 

Awesome collection, beautiful teeth! Moreover, as I understand, very rare finds!