A 15 minute stop in New Jersey and found these Cretaceous...

[CityDweller]

Couple months ago I stopped by the Big Brook Preserve (BBP), a sort of well-known fossil location in New Jersey, about 90 minutes from New York City. It was very muddy so I didn't look around much, but what is great about this place is that it is a road pull off with parking on a nice county road. It was absolutely silent out that misty morning, with deer running about.

 

I found these shells somewhat exposed in the dirt. These are most likely from the Late Cretaceous period (~105-66 MYA), this area was once a shallow marine environment.  Today it is rolling hills, and BBP has a small creek where fossil hunters like to search. The shells display bore holes (from other animals) in them.

 

The State of NJ hosts a very interesting paper on such Cretaceous fossils here: https://www.state.nj.us/dep/njgs/enviroed/oldpubs/bulletin61-I.pdf
 

 

[Jeffrey P]

Those are partial oyster shells- Exogyra costata and possibly Pycnodonte convexa from the Navesink Formation. Big Brook is certainly a great place for Upper Cretaceous marine fossils. Congratulations on your finds.  

[FossilDAWG]

Also, the holes are due to a boring sponge, Cliona.  "Boring" means "making holes" or "drilling into", not "sleep-inducing".

 

Don

[historianmichael]

I was recently at Big Brook Preserve too. It is very silty now. I could not find any of the gravel bars of old. Perhaps the brook has changed after several recent storms.