Fish or reptile teeth?

[gen]

Hi all, 

 

Need a little help identifying these teeth and stem(?) from Herne Bay, UK.

 

Let's call them 1-7 from left to right (top view).

 

Thanks in advance.

 

Jay

 

[mikeymig]

https://ukfossils.co.uk/2012/01/24/herne-bay/

 

Looks like part of a ray dental plate, croc teeth, and crinoid stem.

[gen]

Thanks for the response.

 

Can the first tooth instead be a chimaeridae, rather than ray plate? And can we be sure if the conical teeth are from crocs, not large fish like Xiphactinus?

 

Interesting that the last piece is a crinoid stem - haven't heard of them being found in this location before.

[Fossildude19]

My take on it. 
And yes, it could be a chimaerid tooth instead of ray - other angles would be helpful. 

 

[Mark Kmiecik]

5 hours ago, gen said:

Interesting that the last piece is a crinoid stem - haven't heard of them being found in this location before.

You can see a faint pentagonal pattern on the end shot. Common to many crinoid species.

[gen]

4 hours ago, Fossildude19 said:

My take on it. 
And yes, it could be a chimaerid tooth instead of ray - other angles would be helpful. 

 

Thanks for the nice illustration!

 

I doubt those teeth are shark's teeth though. The cross sections are roughly circular and not flattened on one side as is the case for shark teeth (of the sand shark variety).

 

Reminds me more of a crocodilian, or perhaps a champsosarus?

 

Also attached more pictures of the ray/chimaerid plate and the crinoid stem cross section, where a faint pentagram is indeed visible.

[Anomotodon]

#1 is indeed chimaera, I think only Ischyodus is described from UK Eocene but need to check

#2 looks like a fish Sphyraenodus but could also be a shark crown, need more pics

#3, 4 Trichiuridae indet. fish teeth

#5 lamnoid shark tooth crown

#6 distinct acrodin cap, so Eutrichiurides sp.

#7 crinoid stem

No crocodiles or champsosaurs, reptile teeth are characterized by distinct pulpar cavity and thick layer of enamel, none of these teeth posses these features

 

[gen]

Thank you, that was very informative. I'll add a couple final pictures of #2 and #5.

 

On closer inspection, #5 (right) indeed appears to be a shark's tooth. The profile is flattened on one side. The color and texture is similar to other shark's teeth as well.

 

I am pretty sure #2 (left) is not a shark's tooth. The cross section is distinctly round and there are striations all round. Striatolamna only has striations on one side. There are two distinct ridges on either side of #2 but they do not mark a distinct change in curvature.

[Anomotodon]

You are right, #2 is not a shark but a teleost Sphyraenodus

[gen]

Thank you

[hemipristis]

Very nice find re: chimaerid.