South Texas Upper Cretaceous Shellfish

[CraigHyatt]

Found near Eagle Pass just lying on the ground. According to maps, this region is upper cretaceous. This is a construction site, so the layers may be mixed. The upper layers are hard sandstone, middle are soft sandstone and beach sand, lower layers are mixed hard and soft shale and grey clay. I don't know which layer this specimen came from.

The specimen appears to be in two halves. The photos show the specimen as I found it and with the halves separated. Some shell material is visible around the inner concretion. The closest modern equivalent to my eye would be an oyster. It's about the right size and shape and has the rough outer shell texture. But it's in such bad condition, it's hard to tell.

Ground level above layers.

Edited May 13, 2016 by CraigHyatt

[tmaier]

Oyster or rudist, highly eroded. Your next thing to learn is how to prep fossils. =-)

[CraigHyatt]

Oyster or rudist, highly eroded. Your next thing to learn is how to prep fossils. =-)

Rudist is a good call given some of the photos I've seen: http://www.thefossilforum.com/uploads/gallery/album_1576/gallery_2384_1576_38324.jpg

Yep. I need to learn prep. I'm a bit gun shy because a couple of them dissolved when I tried to wash them. :-) But as long as I take pictures first, no harm in getting some practice removing the matrix with a dental pick. I'll give it a shot on this one. It's so tore up already, it ain't getting much worse... :-)

[GeschWhat]

I just wanted to say that I love that you take photos of where you find your fossils. This will be invaluable when you happen upon that once in a lifetime find!