Douglas Point Finds ID Confirmation

[Snaggletooth19]

Hi all. This past Thursday I made it out to Douglas Point (Paleocene, Aquia Formation). I found the usual assortment of sand tiger shark teeth and some goblin shark teeth too. Unfortunately, finding an Otodus in this formation still eludes me. First is a picture of all my finds. 

 

What I'd like some ID help with are the vertebrae, the two bone fragments, and the crocodile tooth. The last tooth is an interesting one. Looks like a Hemipristis serra tooth to me, though I didn't think they're found in this formation. I included an in-situ photo with the characteristic Douglas/Purse gravel as proof of location. I know it could have washed up from some other part of the river with a Miocene exposure, but it's in remarkable shape for having bounced around for miles in the river. Any thoughts?

 

Thanks all!

 

[Al Dente]

52 minutes ago, Snaggletooth19 said:

Looks like a Hemipristis serra tooth to me, though I didn't think they're found in this formation.

You are correct. It is Hemipristis. Maybe a collector dropped it.

[digit]

@MarcoSr would know for sure if Hemipristis serra occurs in the Aquia.

 

Nice haul--love the verts.

 

 

Cheers.

 

-Ken

[hokietech96]

Never saw a Hemi from that location. Great croc tooth!!  And great finds!!

[FossilDAWG]

A few years ago I found a typical Miocene Isurus at Blue Beach, not far from Douglas Point.  It does seem that it's more common than you would think that people collect at Brownies Beach or other Miocene sites, then drop some teeth at other beaches.  One suggestion was that they might be "salting" sites for kids to be sure they find something.

 

Don

[MarcoSr]

2 hours ago, Al Dente said:

You are correct. It is Hemipristis. Maybe a collector dropped it.

 

1 hour ago, FossilDAWG said:

A few years ago I found a typical Miocene Isurus at Blue Beach, not far from Douglas Point.  It does seem that it's more common than you would think that people collect at Brownies Beach or other Miocene sites, then drop some teeth at other beaches.  One suggestion was that they might be "salting" sites for kids to be sure they find something.

 

Don

 

2 hours ago, digit said:

@MarcoSr would know for sure if Hemipristis serra occurs in the Aquia.

 

Nice haul--love the verts.

 

 

Cheers.

 

-Ken

 

I agree with others above that the tooth is a Hemipristis and the tooth is a contaminant at the site.  Upriver of Douglas Point there are more Paleocene exposures and then further upriver there are Cretaceous exposures.  Downriver of Douglas Point there are more Paleocene exposures, then Eocene exposures, and a good distance downriver there are Miocene exposures.  That tooth did not wash upriver.  The tooth was definitely dropped intentionally (salting for kids etc.) or unintentionally by a collector.  This is why scientists don't trust the provenance of any fossil specimen found in float.

 

Marco Sr.

[Snaggletooth19]

Thanks for the comments, all. I appreciate the insight on the Hemi tooth. What genus of crocodile is typically found in this formation? And any ideas on the bone fragments? Turtle or crocodile?

[MarcoSr]

10 hours ago, Snaggletooth19 said:

Thanks for the comments, all. I appreciate the insight on the Hemi tooth. What genus of crocodile is typically found in this formation? And any ideas on the bone fragments? Turtle or crocodile?

 

See below:

 

 

 

Marco Sr.

[Snaggletooth19]

Wow, that's so awesome and informative Marco, thank you!

[Plax]

I would suggest that the Hemipristis is from a now eroded portion higher up in the section. What we see today doesn't necessarily represent what was at any given site. Shark teeth are much like any other sediment / clast. For instance we get meg teeth here in North Carolina where there is absolutely no evidence of Miocene or Pliocene strata. Or someone may have salted it