Sunday, November 26, 2023

Recent finds from lowcountry waterways - late October 2023

Second out of three posts for October fossil discoveries - October was a good month for several reasons, despite getting covid (for the second time) at the annual meeting of the Society of Vertebrate Paleontology (SVP).
 

Starting in late October, we transition to a different location with a somewhat different suite of fossils. We also transition towards nastier weather: my new boss, Ashby, bought the three of us personalized jackets and needless to say I'm pretty pleased with mine!

This nice inner earbone (periotic) was found by Mike while I was catching up with a colleague who surprised me one morning when she showed up for a tour - he gave me a pretty hard time for walking past this one, which I deserved!

 
This beautiful periotic is from a squalodelphinid - identical to squalodelphinid periotics from the Pungo River Limestone at the Lee Creek Mine of NC. This specimen is probably early Miocene in age.
 
 

This horse tooth was found rolling around in the surf - and capped with a cute little coral colony growing right on the chewing surface! Pleistocene, Equus.


A juvenile Carcharocles angustidens or C. chubutensis tooth, waiting to be picked up.

 

 A spectacular osteoderm (bony armor plate) from the back of an alligator, Alligator mississippiensis! This was found by client Lisa right when we were getting back onto the boat. Pleistocene.

An embarrassingly large mackerel shark vertebra, probably from a megatoothed shark (Carcharocles).

An interesting phosphatic coquina - coquina is a sort of limestone composed entirely of mollusk shells and fragments. We keep finding coquina that is either mixed with phosphatic sand or occasionally phospharized crusts forming on coquina.

Every day we leave past all of these shrimp boats, and it reminds me of Cannery Row in Monterey back home.

A nice tooth of Carcharocles angustidens sitting in a small stream - water pours out of the beach at low tide.

 

A nice delphinid dolphin periotic on the beach.


 On closer inspection, this one is probably bottlenose dolphin (Tursiops).

 

 A great white shark tooth - Carcharodon carcharias.


 It's worth picking up rectangular bones, even if they look like rib fragments.

 This one turned out to be a mandible fragment from Xenorophus! My colleague Kumiko Matsui went home with this specimen.


X marks the spot: this shark vertebra was broken somewhat so you can see the channels through the vertebra.

A vertebra from a lamniform (mackerel) shark.


A fantastic surprise! My marine mammal paleo colleague, Dr. Kumiko Matsui, came down to Charleston with a friend of hers and surprised the hell out of me when she walked down the dock to our boat.


 We had a great time catching up - we didn't have quite as much time to talk shop at SVP two weeks prior, so it was a great opportunity. Dr. Matsui ranks pretty high in my book because she is, as of yet, the *only* marine mammal paleontologist who has come to look at Coronodon since we published it in 2017.


A decent Carcharodon hastalis tooth - formerly "bigtooth" mako.

Thursday, November 16, 2023

Recent finds from lowcountry waterways - early October 2023

The past six weeks have been quite busy - I was swamped with work before SVP (Society of Vertebrate Paleontology), then I had the conference, and then I caught covid for a second time - fortunately, no cardiovascular issues, no long covid, and paxlovid is a helluva miracle drug. Since SVP, Charleston Fossil Adventures has transitioned to our off-season tour spot - but that'll be covered in the next post. October - even with SVP and covid - was so fossil-rich that I'm doing two different posts!

If you want to have a guided tour and be shown how to find (and keep) all sorts of fossils like this, check out available bookings on https://www.chsfossiladventures.com/.

A nice shark vertebra - probably from a small lamniform shark (mackerel shark).

Marsh periwinkles (Littoraria irrorata) may be aquatic snails but they like being *just* above the water. They often climb out of the water and can be found on spartina grass like this at high tide. 

 

A nice example of a tooth of the as-yet-unnamed Oligocene Parotodus - 'false mako' and the lesser megatoothed shark lineage. These are my favorite teeth, and I only find them rarely... two clients found these two days in a row. I photographed this one, Ashby photographed the other.

A lower tooth of Galeocerdo aduncas - easily confused with Physogaleus contortus, to the point where the two were synonymized for a while. Turns out that they can be separated on the basis of compound serrations on the distal part of the tooth.

A nice snaggletooth, Hemipristis serra, sitting in limestone sand.

A very, very small caniniform tooth from a barracuda (Sphyraena).

 
This one puzzled me for a few minutes but Ashby identified it as a partial dentary of a cutlassfish (Trichiurus or Trichiuridae) - kind of fascinating that the teeth appear to break off at the root and new teeth just grow on top of the old ones! But then again, there's a lot about teleosts I don't understand.

 
We see bottlenose dolphins (Tursiops erebennus) all the time on our river and harbor tours - 3 out 5 river tours, and 4 out of 5 harbor tours. This day we saw a whole pod, but only got good photos of this individual - I was filming when multiple dolphins came up. I took this with a CELL PHONE.

 
On one of our accidentally-longer days we decided to head a mile further down the river and check out a slightly larger manmade island with some kind of phosphate spoil or artificial fill on the geologic map - and it turned out to be completely non-fossiliferous. Some of the most beautiful clean white sugary sand in the whole state ended up making up this island - but not a single tooth. Surprisingly clear water - we spent an hour and a half doing some "real Tom Sawyer type shit". It was also just absolutely beautiful.

 
A nice example of a dolphin periotic bone with the ventral surface of the pars cochlearis busted off so that you can see the entire cochlea (aside from the innermost turn, which is missing). This one is probably a bottlenose dolphin (Tursiops sp.) and is likely to be a Pliocene specimen.

 
A large kitefin sawfish rostral spine, Anoxypristis.

 
Snaggletooth specimens don't get much larger than this out on the river - after all they're probably Oligocene, and the species Hemipristis serra underwent a gradual increase in maximum size from the Oligocene through to the Pliocene/Pleistocene.

 
I had one morning tour on Folly beach in early October - no fossil photos, but I did have a rather glorious view just after sunrise.


One of our little unidentified coprolites: these are typically flat and have a very ropy pattern to them - almost like filling up an ant farm with soft-serve ice cream. I imagine these are from some kind of fish.

 
A tympanic bulla of an Oligocene dolphin spotted amongst the gravel - a waipatiid dolphin.

 
A good comparison of a lower tooth of the extinct tiger shark Galeocerdo aduncas (left) versus a tooth of the very similar Physogaleus contortus (right) - note the coarse serrations with finer sub-serrations in on the "heel" (side of the tooth behind the large notch defining the main cusp) of the Galeocerdo tooth and the simple, smaller serrations on the Physogaleus tooth.
 
 
At one of our more secret locations we've been finding some unusual teeth, including over 20 specimens of the sawshark Pristiophorus - sawsharks (Pristiophoriformes) are true sharks (Neoselachii) and within the clade Squalomorphii, along with angel sharks (Squatiniformes), dog sharks (Squaliformes), cow sharks (Hexanchiformes). These teeth (rostral spines, rather) differ from those of Pristidae (sawfish) in having enameloid and a root; the spines of sawfish are all osteodentine. Here's a Pristiophorus tooth and the much larger tooth of a kitefin sawfish, Anoxypristis, found moments apart at the same Oligocene dredge spoil.
 
 
A small tooth of a baby snaggletooth shark, Hemipristis serra.

 
A rather colorful and grumpy mud crab, Panopeus herbstii. 

 
A small megatoothed shark specimen, probably Carcharocles angustidens. Tip top shape!

 
Several marsh periwinkles (Littoraria irrorata) hitch-hiked back into the boat and ended up a few miles down the river from where they normally lived. Hopefully they're too dim to realize it. It's still all marsh, anyway.
 
 
An ?Oligocene specimen of a diodontid, probably the burrfish Chilomycterus - this beak + toothplate is very, very small, less than 1 cm wide.
 

 A sheepshead (Archosargus) left behind by a fisherman. I think it had been gutted. these fish have unusually human-like teeth in the front... and it's all downhill from there once you open the mouth up.
 

And lastly, a cute little fiddler crab (Uca pugnax) I managed to get a photo of. You practically have to run these guys down and sprint at them and snap off a few shots while their little arthropod brains are struggling to make decisions.