Paleocene Brachiopods From New Jersey

[Jeffrey P]

Made a fairly brief visit to a site in Ocean County, near New Egypt, NJ. on Monday 4/6/15. There was a shell bed exposed in a very muddy narrow ravine composed of the Paleocene brachiopod; Oleneothyris harlani. Collected a number of small specimens. They are extremely fragile and usually crumble when exposed. Will return some time to collect, hopefully better specimens.

Edited April 20, 2015 by Jeffrey P

[Herb]

very nice! Would like to trade for some if you get enough to spare.

[Auspex]

Well done!

Collecting intact shells from glaucanite sands can be pretty challenging.

[Jeffrey P]

Well done!

Collecting intact shells from glaucanite sands can be pretty challenging.

Whew! You're not kidding. Got pretty dirty too.

[FossilizedBob89]

These are Nice Brachiopods Jeffrey!

[Plax]

is that round area in the second pic the lophophore showing through from the inside after the shell dissolved away? If so that's one neat fossil.

[Fossildude19]

Well done, Jeff!

Neat finds.

Regards,

[FossilDAWG]

I've collected the same species from a site in North Carolina. For a time in the Paleocene these brachiopods were the dominant shelled organisms and formed banks over a significant part of the Atlantic coastline. The front part of the shell was thick and is commonly the only part preserved, as the posterior is quite thin shelled. I did manage to find one that is complete and with both valves together.

Don

[Jeffrey P]

is that round area in the second pic the lophophore showing through from the inside after the shell dissolved away? If so that's one neat fossil.

I doubt that's the lophophore. It's matrix that filled the shell. Right now I'm leaving it there because the shells are so fragile. Another question is how did the hole get there in the first place. Pretty round to be just random. Possible bore hole from a gastropod? I plan to treat the shells today with Elmers solution to hopefully strengthen the shell material.

[Jeffrey P]

I've collected the same species from a site in North Carolina. For a time in the Paleocene these brachiopods were the dominant shelled organisms and formed banks over a significant part of the Atlantic coastline. The front part of the shell was thick and is commonly the only part preserved, as the posterior is quite thin shelled. I did manage to find one that is complete and with both valves together.

Don

At the site I only saw a couple examples of specimens with both valves together, but they were incomplete. I've seen complete individuals (both valves) at the MAPS (Monmouth Amateur Paleontological Society) collection. Hopefully I can find complete ones next time around. Would love to see pics of your finds.

[fossilnoggin]

nice finds jeff. i've been wanting to collect at that site.

[Jeffrey P]

Don raised an interesting point. In New Jersey the Hornerstown Formation lies just above the KT

boundary. Fossils, I've heard and seen, are generally scarce, probably a product of unfavorable life

conditions that occurred at the end of the Cretaceous. After a period of time marine life began to

recover and in this void, brachiopods briefly reasserted their dominance only to be replaced by

bivalves. These brachiopod fossils cause me to ponder about the conditions during that transitional

time and the course of marine evolution.

[Plax]

The Oleneothyris abundance (bioherm/biostrome?) is at the contact between the late Paleocene Vincentown and early Paleocene Hornerstown. The Lower Vincentown also has them as well as abundant bryozoa making the fauna have a paleozoic look. The K/T boundary is well before this time period but I don't know how many years. There are Pycnodontid oysters and steinkerns of other mollusca in abundance both before and after the occurrence of the Oleneothyris biostrome. The abundance of brachs and bryozoa recurs in the middle to late Eocene Castle Hayne Formation in NC. I believe that water depth and possibly other environmental factors make these habitats suitable to brachs and bryozoa dominance despite what is in print regarding the K/T extinction causing the dominance.

[Shamalama]

Pretty cool finds. Nice to see you getting out.

[Carl]

From what I've learned, Plax is right. During my first visit there I also wondered if the insane abundance of basically nothing but Oleneothyris in these Paleocene sediments was signal of life recovering right after the KT. But those I was with who knew more set me straight. It just seems to be a local concentration due to perfect conditions for these kinds of brachiopods.

[non-remanié]

Indeed, the bed is well after the KT boundary, in the Selandian, ~59mya. There are probably several third order marine sequences included within the Hornerstown fm. I agree with others that the abundance was most likely the result of widespread environmental factors more so than a post KP recovery.

From what I've learned, Plax is right. During my first visit there I also wondered if the insane abundance of basically nothing but Oleneothyris in these Paleocene sediments was signal of life recovering right after the KT. But those I was with who knew more set me straight. It just seems to be a local concentration due to perfect conditions for these kinds of brachiopods.

[Jeffrey P]

The Oleneothyris abundance (bioherm/biostrome?) is at the contact between the late Paleocene Vincentown and early Paleocene Hornerstown. The Lower Vincentown also has them as well as abundant bryozoa making the fauna have a paleozoic look. The K/T boundary is well before this time period but I don't know how many years. There are Pycnodontid oysters and steinkerns of other mollusca in abundance both before and after the occurrence of the Oleneothyris biostrome. The abundance of brachs and bryozoa recurs in the middle to late Eocene Castle Hayne Formation in NC. I believe that water depth and possibly other environmental factors make these habitats suitable to brachs and bryozoa dominance despite what is in print regarding the K/T extinction causing the dominance.

Thanks for setting me and others straight on that.

[Darktooth]

Nice finds jeff