Please Help Id 4 Mystery Verts And 2 Others

[Rustdee]

Hello everyone. I would really appreciate any help in iding these fossils.

I found all of them on the beach amongst limestone rocks that have been dredged up. I have heard from a local that the dredge went about 30-40 feet into limestone. The beach is located on the southern NC coast near Wilmington. I think this would indicate the possible range to be Cretaceous to Pleistocene.

Unfortunately, I really don't have a good handle on how old these are. I have found many fossilized sand dollars, and various shark teeth including tiger, sand tiger, and 2 whites

I believe the 3rd vert to be of a different species than the first two since it is convex on both ends. It is also very worn.

The fourth vert is larger than the other three and is missing a decent portion

Finally, these last two I am not sure what they are. I thought one may be an alligator or crocodile tooth, but it doesn't look like any of the other teeth I have seen.

I would also appreciate any direction towards resources that could help me better id fossils in the future. Thank you for all your help.

Edited July 17, 2014 by Rustdee

[Xiphactinus]

Looks like you have a mosasaur!

[Al Dente]

Nice finds. I think the first vert looks like crocodile or alligator.

[Rustdee]

Thank you both!

The first two do look like other crocodiles that I have seen online, although I have seen a few (not many) verts online that are labeled Mosasaur that look similar. What are the defining features to tell these apart?

I am also very curious about the fourth vert. It is convex on both sides and I have only seen verts online that are concave/concave or concave/convex. I haven't been able to locate what has that shape.

Sorry for all the questions this is all very new to me.

Also, if anyone needs more photos from a certain angle I would be happy to do so.

Thanks everyone!

[Rustdee]

Ok, after scouring various sources I believe the first two are crocodile. The fourth one (biconvex) may be crocodile as well. I am still not sure about the third one (the black vertebrae). How do you tell the difference between mosasaur and crocodile/alligator?

Xiphactinus, which fossil looked like mosasaur to you and why?

I also think the tooth may be crocodile because it doesn't have the cutting edge I have seen on mosasaurs. I am not sure if it could also be porpoise/whale with the root broken.

Finally I haven't been able to find anything like the last bone I have pictured. Any ideas would be appreciated. Thank you all for the help!

[Xiphactinus]

I was thinking the verts looked mosasaur, but I think croc is a better ID.

[Plax]

if the tooth is croc it should have somewhat round concentric rings of growth, a mosasaur tooth has an elliptical depression in the base, I have ball and socket mosasaur verts but these could be croc also, could you show us your sand dollars from the beach? If they are the sea biscuit type like Hardouinea mortonis it would possibly help us date the material.

[Rustdee]

The tooth seems to be fairly circular. I also cannot see any concentric rings inside the tooth. I have also included another bone I have found and the last three pictures are of two bones in matrix. I am not sure what these are, but they may be helpful.

Thanks for all your help!

Edit: I forgot to put a coin in the picture for scale. The sand dollars are between 1.5 - 2 inches in diameter. The solitary bone is approximately 2.75 inches long and the bones in matrix are around 4 inches

Edited July 15, 2014 by Rustdee

[Harry Pristis]

For comparison:

[Rustdee]

Upon very close inspection of the tooth I do see two cutting edges. They appear to be very worn and are opposite each other. Also the tooth is exactly 1 inch long and the base is 1/4 inch in diameter.

I am also attaching more photos of the first two vertebrae in the positions of the chart. I am not seeing an exact match. Both of mine do not appear to have had any structure on the bottom of them.

[Al Dente]

I think your echinoids show two different ages. The first ones look like Hardouinia which are Cretaceous and are a common beach find on Oak Island and Holden Beach. The sand dollars look like a species of Mellita which could be Pleistocene or Pliocene.

[Rustdee]

Thanks Harry Pristis! I am going to need to keep that chart handy! I think mine look extremely close to those, I am just not sure how much variation can exist. For instance, the first vert pictured looks like either the second or third in the chart, but mine has no bottom structure and it doesn't look like it ever did.

Thank you Al Dente for the Id on the sand dollars. I wish that was able to narrow things down a little more though.

Does anyone have any idea on the black vertebrae I have in the first post? It Is larger than the others and looks very different?

[Plax]

If from the beaches that Al Dente suggests I would suspect, Late Cretaceous Peedee formation - vert material and Hardouinea exhinoid, and Late Pleistocene Cane Patch formation - Melitta sp. and Encope emarginata sandollars.

[Rustdee]

Thank you Plax. Would you attribute the verts to Cretaceous due to a lack of marine reptiles in the area during the Pleistocene? Or is it something else? I have been trying to determine when, for instance, crocodiles became absent from the area.

[jpc]

Crocs generally have a single double convex vert near the pelvis. Not so, our friends the mosasaurs.

[Rustdee]

Thank you! So I would venture that the biconvex vertebrae I have would be croc and most likely the other two as well.

Now as for the larger black one I have been doing some reading and I think it could be manatee/dugong.

[Plax]

one could tell by looking at the matrix but I suspect (not certain) your vertebrate material is from the Peedee. Croc is less common that Mosasaur in our latest cretaceous marine deposits but not unheard of. The lag deposit between the Canepatch and Peedee could have almost anything in it though including Pleistocene terrestrial animals. Lags concentrate resistant objects which include bones and teeth. Have seen a plesiosaur vert from the lag at the base of the Waccamaw in Colombus County with early Pleistocene oysters attached for instance.