Vert For Id

[usaman65]

from big brook- a cretaceous/pleistocene site.

id this vert!

[worthy 55]

Snake maybe ?? :huh:

[ebrocklds]

i was also thinking snake, but i am not seeing the process that comes out of the bottom of the centrum. my next guess was bird but i still don't think tht is right. i will keep thinking about it.

brock

[Harry Pristis]

i was also thinking snake, but i am not seeing the process that comes out of the bottom of the centrum. my next guess was bird but i still don't think tht is right. i will keep thinking about it.

brock

Interesting bone, Brock. Vertebrae are difficult.

The Big Brook Cretaceous fossils I've seen have been dark and heavily mineralized. They also have been marine in origin.

It sounds like you, Brock, have already been through the deductive process that is required to eliminate some possibilities. For readers here who are faced with their own ID challenges, here's what I think and why.

I think this vertebra is neither fish nor reptile. Fish have inverted-cone centra. Reptiles and amphibians have ball-and-socket centra. (Turtle thoracic vertebrae are fused to the shell.) That leaves birds and mammals.

Bird cervical (neck) vertebrae have complex, interlocking neural processes which are lacking in this specimen. Bird thoracic vertebrae are fused to one another. There's a chance it could be a bird caudal (tail) vertebra -- I have so little experience of bird fossils, that I could not eliminate that possibility.

The fact that the vertebra has no (or a much reduced) vertical process seems notable. Such a process is an important anchor for muscles in most vertebrae, caudal vertebrae excepted.

A museum comparative collection may be the best resource for ID.

Let us know what you find out.

-------Harry Pristis

[usaman65]

i took it to rutgers and they didnt have much to say.. they thought it could be recent.....

[ebrocklds]

after a bit of research i think that it may be a posterior dorsal to asome sort of rodent. it is similar o a rat but not quite the same. i will keep looking until i find something. what possible recent rat sized rodents are in the area?

[geofossil]

If Cretaceous and terrestrial then it is probably reptile from the order Choristodera. 'BUT' there is a lot of convergent evolution on vertebra shape. small vertebrae are difficult to identify and there are not always definitive answers but rather 'educated guestimates'. I tend to follow deductive logic (as does Harry above) and am inclined to be more certain what it is 'not'... rather than what it is. The age (if Cretaceous), size and shape fits some Choristodera. In my collection I usually content myself with a label such as 'small vertebra: reptilia, aff. choristodera?' and the location.

ebrocklds: I've sometimes gone through contortions trying to figure out a fossil and then discover it is a recent vertebra, tooth, shell from the remains of a recent animal. As you point out it's important to keep an open mind and not rule out the current ecology it is found in.