I Want To Id As Porpoise, But

[Shellseeker]

The relative lengths of root and tip say porpoise, but this is an oddly shaped tip, and it is the 3rd that I have seen like this..

If it is porpoise, why is the tip so odd?

[Boesse]

That is indeed a phocoenid tooth! One of the first genuine looking phocoenid specimens I've seen from the east coast. This is a true porpoise tooth.

[Auspex]

Man, I think you made Bobby's day! Given that he usually has to correct the casual misuse of "porpoise" for east coast dolphin teeth, I'm reading this as a rare find!

[Shellseeker]

Thanks Bobby,

I always poke around and found this link with a photo of what I call small "button top tooth".

http://www2.wdcs.org/fieldblog/index.php?/archives/2010/10.html

I have found exactly one of those button top fossil teeth in 5 years in the Peace River and a fossil buddy, who found this tooth, yesterday has been looking in the Peace River for 25 years. Neither of us were positive on an identification.

These are very rare where I hunt. Normally I find the longer pointy but flat tip kind and even those are relatively rare. SS.

[Boesse]

Yup yup, that's it. Extant phocoenids have what are called "spatulate" teeth; many fossil phocoenids from the late Miocene and Pliocene of the Pacific are still delphinid-like and have conical teeth, but a few that are really closely related to the modern species do indeed have spatulate teeth. Now, as of yet there is only one Pliocene phocoenid from the Atlantic, and it's from Belgium. These teeth, I believe, are some of the first specimens of phocoenids from the western Atlantic. Problem is, since these are river finds there's not really any way to identify the source stratum. However, since there are zero specimens from the Yorktown, my vote goes for these being younger - late Pliocene, or Pleistocene in age, when harbor porpoises (or predecessors) first made it into the area.

Finally, a bona-fide porpoise tooth. Whenever somebody posts a picture of a conical dolphin tooth and says they've got a porpoise, I'm going to link to this post.

Bobby

[Shellseeker]

Bobby,

Look at the picture (lower right corner) at this LINK:

http://www.knewance.com/comparisons/tag/nature?currentPage=5

I am learning something here!

[Roz]

Very nice find!

[JohnJ]

Awesome "new" find, SS. Those finds keep the 'fossil motor' running.

[RichW9090]

VFOM candidate, for sure!

[Al Dente]

I'll play devil's advocate. How do we know it isn't a canine from one of the horses like Merychippus?

picture from this page:http://www.cosmosmagazine.com/news/ancient-teeth-reveal-hungry-horse-evolution/

[siteseer]

Al Dente,

Merychippus and its close relatives (many species once assigned to Merychippus now belong to other genera) lived during Hemingfordian and Barstovian time (Early-Middle to Middle Miocene or about 14-18 million years ago). You tend to find Late Miocene and younger (no older than maybe 9 million years old) fossils in the Peace River. I believe one of the formations exposed by the Peace is the Bone Valley Formation and the lower layers do range into that time but fossils from it are rare/very rare (generally found in certain phosphate mines). Also, that specimen looks too big for a Merychippus canine. A molar might reach that height so a canine would be smaller.

Still, it would be an interesting question for a mammal specialist since my comments only indicate an unlikelihood.

Jess

I'll play devil's advocate. How do we know it isn't a canine from one of the horses like Merychippus?

merychippus.jpg

picture from this page:http://www.cosmosmagazine.com/news/ancient-teeth-reveal-hungry-horse-evolution/