Walnut Formation Crab

[erose]

So I have been sorting, cleaning, high-grading and cataloging while stuck at home.  I have been concentrating on material from the Walnut Formation of central Texas. The Walnut is the lowest formation of the Fredericksburg Group (Albian).  Lower Cretaceous or if you're old school Comanchean.

 

I have fossils from the west side of Austin all the way north to near Gatesville, TX.  There are numerous members but the main ones I have collected from are the Bee Cave and Keys Valley Members.  The Bee Cave mostly near Austin and the Keys Valley further north.  This little crab was found in between near Georgetown, TX in the Keys Valley Marl Member almost seven years ago while collecting with JohnJ.

 

This site produced another really cool new crab: Cenomanocarcinus cookseyi (Osso, et al., 2015) named for Bob Cooksey, one of our fellow FF members.  Bob and JohnJ made sure that awesome specimen got into the right hands and was described. Kudos to both Bob and John!

 

But I digress...   

 

I had found this specimen and it was mostly buried under matrix (oops no pre-prep pic) but enough was showing to tell me there was something worth while to be exposed. And at the time I thought it would prove to be another C. cookseyi.  Well as I slowly picked away at it I realized it was something different.  The specimen isn't perfect. The rostrum and orbits are gone as far as I can tell and there is some compression on the left side. But otherwise it is in pretty good shape.  Please take a look and let me know if you might know what genera or species it is.  The closest thing I have found is Aetocarcinus muricatus Schweitzzer et al., 2016, which is known from the Upper Glen Rose Formation (a tad older...) But there are a bunch of species shared between both formations.

 

 

[JohnJ]

@erose

 

Erich, it could possibly be Juglocarcinus tumulus (Garvie, et al., 2017) described in A new family, genus and species of crab (Crustacea, Decapoda, Brachyura) from the Cretaceous (middle Albian) of Texas.
 

But, I'm not entirely convinced they share enough similarities.  

 

[erose]

1 hour ago, JohnJ said:

@erose

 

Erich, it could possibly be Juglocarcinus tumulus (Garvie, et al., 2017) described in A new family, genus and species of crab (Crustacea, Decapoda, Brachyura) from the Cretaceous (middle Albian) of Texas.
 

But, I'm not entirely convinced they share enough similarities.  

 

Ok, I’ll take a look and see if I can find that paper.

[JohnJ]

13 minutes ago, erose said:

Ok, I’ll take a look and see if I can find that paper.

 

Check your email.   

[erose]

Got it. Thanks! I’ll take closer look in the morning.

[erose]

3 hours ago, JohnJ said:

@erose

 

Erich, it could possibly be Juglocarcinus tumulus (Garvie, et al., 2017) described in A new family, genus and species of crab (Crustacea, Decapoda, Brachyura) from the Cretaceous (middle Albian) of Texas.
 

But, I'm not entirely convinced they share enough similarities.  

 

I think this may indeed be the critter. Aetocarcinus muricatus has more spines than mine and Juglocarcinus tumulus looks to be a match for what I can actually see.  Once gain thank you JohnJ.