Shelling Along the Chesapeake

[historianmichael]

Inspired by trip reports by other members on the fossil shells of the Middle Miocene Choptank Formation, especially @I_gotta_rock's report from 2018, over the past several months I have made a couple trips to Matoaka Beach Cabins in Maryland to collect some of the incredible invertebrate material exposed along the cliffs and in that way draw the quizzical looks of other collectors there combing for shark teeth. It is a lot of fun to just park myself along the beach and break down pieces of talus with a screwdriver to uncover hundreds, if not thousands, of shells. Unfortunately the shells are incredibly fragile so a lot of effort was taken to wrap the fossils in aluminum foil on the beach and to meticulously expose them with dental tools and toothbrushes and consolidate them with glue at home. Despite my precautions, many shells were lost, both on the beach and at home. I found everything along the beach and in talus falls, except for the large piece of the sand dollar Abertella aberti. On my latest trip to the Chesapeake Bay a man collecting shells along the beach asked me to identify a few things that he had found washed in by the tide. He asked if this fossil was a piece of turtle shell and when I told him that it was instead a piece of sand dollar and that it is rare to find a piece that large, he asked me if I wanted to have it. I of course graciously accepted his offer. I offered a couple of other fossils later on, but he seemed satisfied with what he had already found.

 

There are so many fossil shells to be found along the cliffs of the Chesapeake Bay so I will try not to bore you with all of my finds. I think the gastropods are really cool so I have included all of my gastropod finds.

 

Without further ado, here are my favorite finds:

 

The only vertebrate fossil I found was this Aetobatus sp. ray tooth that was found lodged inside the opening of an Ecphora shell

 

What is a post about Miocene shell collecting without a big Balanus concavus barnacle. This one was found in about six inches of water at low tide on my first trip.

  

 

About the same time I found the barnacle I found this awesome chunk of Astrhelia palmata coral, which even has some bryozoan on it

  

 

A couple crab claws found while searching the excess matrix compacted in the shells

 

 

The aforementioned piece of the sand dollar Abertella aberti

 

 

Now for the shells. First off are a couple Chesapecten nefrens. I love to find ones that have barnacles still on them.

 

 

This was my largest one, measuring about 6 inches across.

 

I found one that had both valves, but sadly one of the ears is missing

 

 

Chesacardium laqueatum blackwelderi

 

Atrina harrisii

 

Stewartia anodonta

 

Dosinia acetabulum blackwelderi

 

Timothynus subvexa

 

Ostrea carolinensis

 

The largest shell found along the beach is the geoduck clam Panopea americana

 

 

You can also find another species - Panopea goldfussi. I love how this one preserved in life position. All I had to do was dig some of the matrix out and glue the rest in.

 

 

Glossus marylandica

 

Mercenaria cuneata

 

While finding the big gastropods was the real draw, I also really liked finding the tiny gastropods, which I only found at home after screening extra matrix or breaking extra matrix down by hand. The first of the tiny snails to show off are these three species of Calliostoma. From left to right is Calliostoma aphelium, Calliostoma philanthropus, and an unknown species of Calliostoma.

  

 

Perhaps my favorite tiny gastropod - the predatory murex snail Typhis acuticosta

 

I believe this one is Surcula sp.

 

Perhaps the smallest fossil I have ever found- Teinostoma calvertense. Can you see it in the photo on the right? 

 

 

Terebra sp.

 

Cymatosyrinx limatula

 

Mariadrillia parvoidea

 

Nassarius peralta

 

Nassarius peraltoides

 

Neverita duplicata

 

The moon snail Euspira heros is by far the most common gastropod. I found a dozen of different sizes. Here are only a few.

 

Mariacolpus octonaria

 

Turritella subvariabilis

 

Crucibulum costatum

 

Crucibulum multilineatum

 

Scaphella virginiana

 

 

I love this juvenile Busycotypus rugosum whelk shell

 

 

Spinifulgur spiniger oslowensis

  

Edited May 17, 2021 by historianmichael

[historianmichael]

Amalthea marylandica

 

Siphonalia devexa

 

 

Siphonalia sp.

 

 

Last and certainly not least are the Ecphora meganae meganae that I found. In splitting blocks of matrix, I found about 8 Ecphora in varying conditions. More often than not some part of the shell was missing during fossilization or the shell was simply riddled with cracks. I found one with the tip of the shell still attached, but it was missing the lower half. Only two were more or less complete - a juvenile and a more mature one. In cleaning the more mature one I accidentally broke a piece to it, and then that piece broke into two pieces, but luckily I was able glue it all back together. You can still see where I broke it, but it is all there and that is what is important. Here are my four more complete Ecphora meganae meganae.

 

The mostly complete juvenile Ecphora

 

And by far my best find to date

 

And a photo of how I found it

Edited May 17, 2021 by historianmichael

[NickG]

Very gorgeous work. You're making me pine to get back to the western shore again!

How many hours do you think you spent all in all on preparation?

[Praefectus]

Beautiful shells!

[Al Dente]

5 hours ago, historianmichael said:

Amalthea marylandica

Nice to see someone showing invertebrates from this site. Your Amalthea is actually the inarticulate brachiopod Discinisca lugubris.

Edited May 17, 2021 by Al Dente

[Max-fossils]

What an incredible diversity of mollusks, and such gorgeous preservations as well. This thread made me drool! 

Thanks for sharing, and well done on this impressive haul!

[historianmichael]

Thank you all for the kind words. It was a lot of fun to collect these and I hope to get back there soon to hopefully find something new or better. One of the shells that I found that did not survive fossilization was a larger whelk shell. Most of the shell was not there. I would love to find another one of them.

 

@Al Dente Thank you so much for the ID! I was dissatisfied with that identification when I made it. It kinda looked like the drawing in the Maryland Miocene Plates but I couldn’t find a photo of it online. I will make the change on my reference card.

 

@Nick G. The real challenge in prepping these shells is not the actual removing of the matrix from the shells, but the waiting for the matrix to dry so that it comes off the shells really easily. If the matrix is still wet it won’t come off and you will end up breaking something trying to get it off. For reference it took two weeks from my last trip to when I finished cleaning and consolidating my finds, but I wasn’t working on them 24/7 and I did have a number of them to get through. When I removed the really nice Ecphora from its matrix block about two weeks after I had found it, the matrix on the buried side of the shell was actually still wet and I had to wait an extra day for it to dry before I could finish my work on it. It takes a long time!

[Andy B]

Those barnacles are amazing!

[Ludwigia]

Great finds! What a variety!

[traveltip1]

Great report,  ID and prep

[ClearLake]

Those are awesome!  I have only had the opportunity to visit that location once and I also focused on the inverts (left finding most of the sharks teeth for my wife) but would love to go back as I couldn’t spend nearly enough time and therefore only have a fraction of what you have collected. Great work on prepping and ID’ing!

[Jeffrey P]

Wow, Michael! What an awesome diversity of Miocene shells! Thanks for posting these. 

[I_gotta_rock]

Sweet haul!

[jerseygurl]

Wow! Thanks for posting. I really enjoyed browsing the finds. 

[frankh8147]

Great finds! That's a really nice place to collect!

[Searcher78]

Awesome finds.  I am always amazed at how many unbroken shells that can be collected from that area.  Unfortunately, since I am limited on room, I keep my collection to shark teeth.

[HemiHunter]

On 5/16/2021 at 11:54 PM, historianmichael said:

What is a post about Miocene shell collecting without a big Balanus concavus barnacle. This one was found in about six inches of water at low tide on my first trip.

 

Holy moly, that is a massive one! Thanks for helping me appreciate the fossils at Matoaka that I all too often ignore in favor of vertebrate stuff.

[Northern Neck]

Very nice work! Thanks for the details and photos!! 

[Trevor]

All these invertebrates are beautiful! Thank you for posting this @historianmichael!

[historianmichael]

Thank you all so very much for your wonderful comments. It took some real effort to extract these shells from their sandy resting places and properly preserve them, so it means a lot to see other people enjoy them too. While I would certainly love to find a big shark tooth or large whale vertebra there, I have continued to be amazed by the diversity of invertebrate fauna at just this one site. You never know what you are going to find. Earlier this week I screened a small amount of excess matrix left in my bucket after cleaning the last of the bivalves I found, and I ended up finding a "new" gastropod to add to my collection: Epitonium humphreysii. I actually found the same species in January during a visit to the Late Miocene Eastover Formation in Virginia, so it was excited to find another one, especially one that is several million years older. This particular gastropod still exists today, so it just goes to show you how long this species has been around for.

 

[Coco]

Nice shells, and I love Epitoniidae !

 

Recent species : https://www.google.com/search?q=epitonium+clathrus&client=firefox-b-d&sxsrf=ALeKk00N5bgf6_W40-HdayG6UO3g2REJgQ:1621756846320&source=lnms&tbm=isch&sa=X&ved=2ahUKEwirpPKFq9_wAhWzAGMBHRXwB28Q_AUoAXoECAEQAw&biw=1599&bih=815

 

Coco

Edited May 23, 2021 by Coco