Two Bones from the Texas Pleistocene

[GPayton]

Hey everybody! I've got two bones that I'm looking to ID, and unfortunately neither of them are complete. However, the good news is that they both have enough diagnostic features that I'm optimistic an ID can be made. 

 

Here's the first:

 

This first one is a partial limb bone that I found in a river southwest of Houston. The sediments that make up the river bed are from the Beaumont and Lissie Formations and are predominantly Pleistocene in age (although there is the occasional Pliocene/Miocene material that washes down from further upriver). What stands out to me the most on this bone is the giant foramen that seems to connect to a large hollow cavity near the surface that was broken open when the bone was damaged at some point in the past. I can't tell if this is natural or some sort of drainage port that developed because of a pathology like an abscess. @Harry Pristis has several photos of a pathological alligator metapodial that gave me the idea: 

 

 

Half of an articular facet from one end of the bone is fragmented, but still present. It reminds me of the curvature found on the distal end of horse tibias. Unfortunately, it's a little bit difficult to capture it on camera. 

The only other distinguishing feature of the bone is its flaky surface. It could just be due to the particular way it was preserved, but I don't think I've ever come across another fossil with a similar texture. 

 

Here's the second bone:

 

This second bone seems like it should be much easier to identify as it has two very distinctive articular facets preserved. Three foramina are also present, and enough of the long portion of the bone seems remain that it's general shape can be inferred. 

When I look at it I'm reminded of a calcaneum but after comparing it to horse calcanea (of which I have two), I can't see a match. The same goes for bison and other artiodactyls, even giant armadillos. I'm not sure what else it could be. 

 

As always, any help would be much appreciated! I know there are many people on the forum who are much more knowledgeable when it comes to Pleistocene fossils than me, so I'm once again going to ask for their opinions as well. @Shellseeker @garyc @Lorne Ledger @Harry Pristis

Edited August 16, 2022 by GPayton

[Brandy Cole]

Number two reminds me of a reptile humerus for some reason.

[garyc]

Check out giant tortoise humerus as a possibility 

[Shellseeker]

What Gary said...

On the 1st,  I ran across a foramen while searching for an Identification on a leg bone. I will have to find the post....

[GPayton]

Thanks for the suggestions @Brandy Cole, @garyc, and @Shellseeker! I've spent the last several hours looking for some good comparison pictures of tortoise humeri and have only found a handful that show the end of the bone that I think you're all talking about, one of which is one that @Harry Pristis took:

 

 

Unfortunately I can't really see how the distinctive articular facets on my bone match up with the relatively rounded, smooth end that's present on a tortoise humerus. The general shape is right though. Does anyone have some better pictures that show what you're all talking about better? This is one of those times where I wished I hadn't left my copy of Hulbert's book on Florida vertebrate fossils back in Waco for the summer!  

Edited August 17, 2022 by GPayton

[Shellseeker]

55 minutes ago, GPayton said:

Thanks for the suggestions @Brandy Cole, @garyc, and @Shellseeker! I've spent the last several hours looking for some good comparison pictures of tortoise humeri and have only found a handful that show the end of the bone that I think you're all talking about, one of which is one that @Harry Pristis took:

 

 

Unfortunately I can't really see how the distinctive articular facets on my bone match up with the relatively rounded, smooth end that's present on a tortoise humerus. The general shape is right though. Does anyone have some better pictures that show what you're all talking about better? This is one of those times where I wished I hadn't left my copy of Hulbert's book on Florida vertebrate fossils back in Waco for the summer!  

I think most of us do not recognize the bone. On the 1st photo, I thought Calcaneum because of the facets. but quickly switched... Think of the radius and the tibia you mentioned.... these bones are straight...they do not have wild curves that bend back on the curve at the joint....

Basically, the bone you seek is a Humerus,  and although you found a large bone, the humerus we showed you is 30 mm,,,,

You have a large bone,  4 inches for likely less than 1/2 the length of the bone.... How about this?

 

or this ?

 

So, you have a sense of the larger reptiles and mammals that were living in the Texas Pleistocene,  that have a bone like a Humerus which has a nasty "S" curve, and the distal end bends back on the curve.

 

I thought it would be reptile , more likely Tortoise or Sea Turtle,  than mammal, but who knows... Those facets are red flags... So, you are doing the right thing... maybe someone will come along and tell you, But , in the event , no one does,  start searching the net for Reptile/Mammal name, Humerus.. 

 

[GPayton]

I definitely understand what you're saying about the s-curve @Shellseeker - when I look for matches, it is a feature that's only present amongst reptiles. 

The difficulty I'm experiencing when trying to match the bone to a tortoise or alligator humerus is that the proximal views of the ends of humeri in both those species that I've been able to find look nothing like the facets that are present on my bone. Here's a photo showing one end of a turtle humerus: 

Neither the proximal nor the distal ends look much like what I have - they're mostly convex to fit into a socket joint rather than concave like the two unbroken facets on this bone. But with the s-curve you mentioned being so obvious when I look at the bone in side profile, I can't imagine what else it could be. 

[GPayton]

@Shellseeker - throwing out a wild guess, do you think it could maybe be a sloth calcaneus? The pictures I've seen definitely have the steep s-curve that we've been talking about and it seems to be in the right spot. Two out of the three articular facets I have on my bone seem to match, with a third being broken off. Here's some pictures I found for comparison (although the best ones I could find were on an online auction listing, so they should be taken with a HEAVY dose of salt): 

 

If I'm totally off base, feel free to correct me. Half the time I have no idea what I'm talking about. 

[Shellseeker]

13 hours ago, GPayton said:

@Shellseeker - throwing out a wild guess, do you think it could maybe be a sloth calcaneus? The pictures I've seen definitely have the steep s-curve that we've been talking about and it seems to be in the right spot. Two out of the three articular facets I have on my bone seem to match, with a third being broken off. Here's some pictures I found for comparision (although the best ones I could find were on an online auction listing, so they should be taken with a HEAVY dose of salt): 

 

If I'm totally off base, feel free to correct me. Half the time I have no idea what I'm talking about. 

Absolutely  !!!! You have it  !!!! Feels Good ...

[GPayton]

One of my most-wished for finds for as long as I've been fossil hunting has been anything identifiable from a ground sloth - doesn't matter how big or what condition it's in. Today I can finally check that off my bucket list! Now to up my standards and find a claw...

Edited August 17, 2022 by GPayton

[Brandy Cole]

Fantastic find! @GPayton

[Fin Lover]

Congrats on checking something off the bucket list!