Thursday, December 7, 2023

Recent finds from lowcountry waterways - early November 2023

October was great at our new off-season locality, but things really started to take off in November - one of the best months of fossil collecting in my life. 


A nice periotic of Squalodon proper! An actual, factual South Carolina Squalodon specimen. We've encountered a few teeth, but this is one of the first periotics that's been a good match. Tough to tell the difference from Ankylorhiza, though they are somewhat smaller. A bit eery that the periotic is highly convergent...
 
 
A rather large tooth fragment of a spotted eagle ray, Aetobatus. We usually just find chunks.

 

A beautful posterior tooth of the ancestral megatoothed shark
Carcharocles angustidens - look at how stubby this one is!
 

 A large sampling of snaggletooth specimens -
Hemipristis serra.
 
 


 We also had some great - but sobering - sightings of Tamenend's bottlenose dolphins (aka Altantic coastal bottlenose - Tursiops erebennus). This individual gave us an unparalleled sighting opportunity - but only because it was begging for food. Once it realized (after only about a minute) that we weren't tossing any shrimp or bycatch overboard (like the shrimpers just a few boat lengths away) it swam off into the harbor.


At one particular spot we tend to find a lot of lined sea stars, Luidia clathrata, at low tide. These are 'doomed pioneers' that venture above the low tide line on the sand flats and get stranded. I tossed about 15 of them back into the surf on this day in particular.


This one was quite possibly the most frustrating false periotic I've ever come across. I actually filmed it, I swore it was going to be a delphinid periotic bone! Just a phosphate nodule with a rough trilobate outline and a cluster of holes looking like the endocranial foramina.


A massive chunky horse tooth from the Pleistocene! Still has all the cementum on it, which is frequently spalled away.


At this locality there are tons of well-preserved steinkerns (internal molds) of ancient quahog clams (genus Mercenaria). So, we collected a bunch and I made a temporary art installation on the beach. 


A Miocene earbone (tympanic bulla) of some kind of dolphin, probably (but uncertainly) a eurhinodelphinid.
 

 A legend-class cutter operated by the US Coast Guard, spotted in Charleston harbor just near the main shipping channel - I think this could be the James, but there are several other cutters that are based out of Charleston: Hamilton, Stone, and Calhoun. That's 40% of the entire fleet! The only other port that operates as home base to four different cutters is also a place I call home: Alameda, California. Note that this thing is basically a lightly armed frigate - it's got a 57 mm Bofors deck gun on the bow and several antiaircraft guns. It's times like this when you remember that the US Coast Guard is officially a branch of the armed forces and a bit of a light navy.


A small lightning whelk (Sinistrofulgur perversum) in beautiful shape! These are rare, perhaps you find one lightning whelk shell for every ~25 or more knobbed whelks (Busycon carica). Knobbed whelks are the most common large gastropod along the Carolina coast.


A partial balaenopterid whale periotic - the pars cochlearis here has been busted off from the body of the periotic, showing us a great partial endocranial view of the cochlea - the spiral organ of hearing. This specimen has at least two complete turns of the cochlea.


A different periotic, and one that is also incomplete, but with an intact pars cochlearis. This is from an as-yet unidentified, but relatively common, early Miocene dolphin we keep finding - that bears similarities with an unpublished platanistoid dolphin from Europe.


A megatoothed shark tooth in the sand (Carcharocles sp.).


A decent haul from one of our longer days out there (Ashby sorting fossils on right).


Some of my favorite finds are those that others clearly walked right by. Here's a partial Carcharocles megalodon tooth right next to someone's bootprint!


A megatoothed shark tooth poking out of wet sand (Carcharocles angustidens/chubutensis).


Extruded sand from some kind of invertebrate - I think, based on prior reading, that this is from some sort of large burrowing annelid worm.


A juvenile tooth of Carcharocles megalodon in a few millimeters of water.
 

 Ashby called me over as he understands my inordinate fondness for intertidal invertebrates: a mantis shrimp! Based on a quick search on Inaturalist, this looks like it might be a juvenile West Atlantic Mantis Shrimp (
Squilla empusa). I carried it to the water in a large shell, but dared not get my fingers close! I'm much too attached to them. My fingers that is, not invertebrates.
 

 A robust tiger shark tooth -
Galeocerdo cuvier, from the Pliocene.
 

A colorful sea whip (
Leptogorgia virgulata) - these quite commonly wash up along certain places in the harbor. This species can be yellow or magenta. Sea whips are gorgonians - soft corals, aka octocorals - and are closely related to the sea fans, their more famous tropical cousins.
 

A juvenile
Carcharocles chubutensis tooth - possibly Carcharocles angustidens, as these two species really grade together around the Oligocene-Miocene boundary.
 

A veritable smorgasbord of fossils from one of our better days out on the harbor.
 

 A stingray- or skate-bitten dugong rib! These traces are formed by batoids with pointy teeth and which draw their bite posteriorly, rasping away flesh from a bone.
 
 
A large snaggletooth specimen (Hemipristis serra) propped up between two oyster shells.


We had one day out there where we found nine different cetacean earbones! Most were partial bullae, but there's an unusual mysticete periotic in there, a good waipatiid periotic, an acid-digested xenorophid bulla, and a pygmy sperm whale bulla.



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