Nj Paleocene - Vincentown Fm

[pinkus]

I collected a ton (well, more like three pounds) of material from the Vincentown Formation when a neighbor's well was dug a while back. Most of the material is chunks of bivalve but there are also bryozoans and echinoid spines. Some of the bivalve chunks are complete enough to ID but I am at a loss for references to help me. I have "Bryozoan Fauna of the Vincentown Limesand" by Canu and Bassler which should cover the bryos, but the only works I have to help with the bivalves are Weller's 1907 book and Whitfield's 1886 Volume.

Any suggestions for resources or any help with IDs from the photo? Top and bottom are specimens that I believe to be the same species to show both the inner and outer surfaces.

[pinkus]

These are the chunks that didn't make the cut to be potentially identified.

[pinkus]

Should also mention that the well was being dug in Monmouth County, Howell Twp, and these were from a depth of ~160 feet. I might not be remembering the depth correctly but it was over 100 feet anyway.

[FossilDAWG]

Several of your specimens (1 and 4, numbered from left to right, on both the top and bottom rows) are a brachiopod, Oleneothyris, almost certainly Oleneothyris harlani (Morton). (link) This brachiopod forms a biostrome that is widespread across the Vincetown, and occurs in Paleocene rocks as far south as North Carolina.

This brachiopod was recently discussed in the forum here.

Don

Edited June 3, 2015 by FossilDAWG

[pinkus]

Thanks Don. I've only seen casts of Oleneothyris so it wasn't obvious to me.

[non-remanié]

I agree with FossilDAWG's. Almost surely Oleneothyris harlani from the basal Vincentown formation Oleneothyris biostrome bed. There is a known, but very poor outcrop in the vicinity of Howell. The vast majority of pieces are probably Oleneothrysis. It would be difficult to ID anything further.

[Diceros]

Just one comment on the lt. Paleocene (Thanetian) brachiopods - the first in the upper row is a pedicle valve (you can see the hole for the pedicle [a stalk which holds these articulate brachiopod to the sea floor] at the top), and the fourth in that row is the brachial valve, the side that holds all the fancy internal structures.

I don't think you should give up so quickly on the other valves. Nos. 2, 5 & 6 in both the top and bottom rows appear to be pycnodontine oyster valves, mostly the rt. (or upper) valve. Possibly a small Pycnodonte itself.

A word about the two holes in top row, no. 3. These are a trace fossil boring (Oichnus isp.) which I haven't seen much on recent posts. They're holes usually made by naticid snails (moon shell-type), mostly into clam or oyster valves (often near the umbo), when the snail is eating the clam (score one for the Gastropoda!). They make the hole with their radula, then I think stick it down into the soft part of the clam, liquify it, and suck it up, as if by a straw. It's sort of like the way spiders eat. Call me old-fashioned but, to me, that's no way to eat. I think eating should involve teeth and chewing, but that's just my biased mammal viewpoint.

A couple of comments on the Vincentown - it's a nutrient-rich, shallow, clear-water environment. It's the sort of habitat filter-feeders like bryozoans, brachiopods, gorgonians (soft coral), and echinoids love, because there's no mud to foul their feeding equiptment. It's a very diverse fauna, although there could be more vertebrates. In the early work of the early 1800's, it was incorrectly considered a late Cretaceous fauna.

[pinkus]

Thanks Diceros. Yeah, 2, 5, and 6 are certainly different. I will keep searching around. And I too am glad I'm not a gastropod.

[MikeR]

C.W. Cooke in USGS professional paper 321 described a relatively diverse echinoid fauna from the Vincentown Formation. One of my biggest fossil collecting regrets is that I did not investigate the sites while I was living in Eastern Pennsylvania.

[pinkus]

Wow. Who new there were so many species of echinoids in NJ. I've downloaded the paper. Thanks for steering me to it.