Shark Tooth Hunting in the Potomac

[historianmichael]

A few weeks ago my girlfriend and I decided to take advantage of the unusually warm December weather in Northern Virginia to visit the historic Stratford Hall and make a couple quick stops at the Miocene deposits in Westmoreland State Park and Stratford Hall and the Paleocene deposits in Purse State Park. To say the least, this trip was planned a bit on a whim. I was thoroughly unprepared - lacking boots or waders and having to buy a cheap plastic colander at Target to do some sifting. Luckily the Potomac River was cold, but not that cold, so I was able to wade out in my bare feet up to about my knees. This was also my first time collecting along the Potomac and I totally messed up the tide tables. By the time we made it to Purse State Park, it was high tide. There is little to no beach exposed at Purse at high tide, so my hope to do some surface collecting for larger shark teeth went totally out the window. Lesson learned! I ultimately brought home two gallons of gravel to sort through. Almost all of my finds are from that micro matrix. As expected there were a lot of broken shark teeth and ray teeth. I only included here the ones that I decided to keep. I tried very hard to identify these small teeth from Purse. I am sure @MarcoSr and others who know these sites far better than me will tell me that I got everything wrong. 

 

Here is a photo my girlfriend took of me wading out in the Potomac at Westmoreland State Park. You can see that my legs had grown red and numb from the cold water 

 

Our finds from Westmoreland State Park. We collected here for only about 45 minutes. We found three requiem shark teeth (Carcharhinus egertoni), a lemon shark tooth (Negaprion eurybathrodono), a tiger-like shark tooth (Physogaleus contortus), a sharpnose shark tooth (Rhizoprionodon fischeuri), and several pieces of whale bone.

 

After spending several hours at the museum and plantation house at Stratford Hall, we made our way to the Fossil Beach at Stratford Hall. To my surprise we were the only ones there. Here are our finds after about 40 minutes of collecting. We found two snaggletooth shark teeth (Hemipristis serra), a requiem shark tooth (Carcharhinus egertoni), an eagle ray medial tooth (Myliobatis sp.), and several pieces of whale bone.

 

Our finds at Purse State Park were much more varied, including both shark teeth and invertebrates. Although shark teeth and the occasional crocodile tooth are the real highlights of the Aquia Formation, I was excited to find these four nearly complete Ostrea alepidota oysters with both valves. 

  

 

An interesting Pitar pyga steinkern

 

Some Turritella sp. steinkern pieces

 

Paralbula marylandica

 

Scomberomorus sp.

  

 

An unknown bone fragment, probably bony fish

 

Cow-Nose Ray Medial Teeth (Rhinoptera sp.)

 

Eagle Ray Medial Teeth (Myliobatis sp.)

 

Eagle Ray Lateral Teeth (Myliobatis sp.)

 

Angel Shark (Squatina prima)

 

Tope Shark (Galeorhinus sp.)

[historianmichael]

Goblin Shark (Anomotodon novus)

    

  

 

Smalltooth Sand Tiger Shark (Odontaspis winkleri)

 

Sand Tiger Shark (Striatolamia striata)

 

 

Sand Tiger Shark (Hypotodus verticalis)

   

  

 

 

Sand Tiger Shark Symphyseal Teeth (Hypotodus verticalis)?

 

[Fossildude19]

Nice finds and report, Michael.

Thanks for posting.  

[Praefectus]

Nice finds!

[hokietech96]

Great finds!

[MarcoSr]

Nice finds.  Most of what you have identified seems reasonable with a few exceptions.  There are at least seven species of Sand Tigers at Purse State Park which can be very difficult to separate and ID.  Lateral teeth are the easiest for me to separate.  Anterior teeth are more difficult and posterior teeth mostly impossible to separate.  Striatolamia are by far the most abundant Sand Tiger teeth found at Purse State Park.  A lot of your teeth look more like Striatolamia teeth to me.  Differentiating  Myliobatis from Rhinoptera pavement teeth has always been very difficult for me.  I use mostly how they interlock, their root features and if the crowns slant to try to separate them.  elasmo.com has an icon " MYLIOBATOID Teeth" on the home page, which if you clique on it, will display the best discussion that I have seen on telling them apart.  Even understanding this discussion, I have a lot of problems telling worm teeth apart.  From what I can see of the roots, you have them mixed.

 

Marco Sr.

[cck]

Nice to see your finds Michael! I could be wrong, but these look like otodus to me?

[Northern Neck]

Nice work! I can't find much at Westmoreland state park these days.  I may try this week just to see what's there though since the crowds are slim now.  I did find an almost 2 inch sand shark tooth at purse.  By far my biggest.  Took my daughter there and came away with nearly 400 teeth but all are so small.  Last time I went to purse in September it was slammed and you couldn't even get a parking spot. 

[Clint08]

Great report, and looks like you were able to find some nice pieces even though the tides weren't the best!

[Notidanodon]

On 27/12/2020 at 10:15 PM, cck said:

Nice to see your finds Michael! I could be wrong, but these look like otodus to me?

They all have nutrient grooves so they are sand tiger