I posted this a long time ago ( I think before TFF crashed, because I can't find the original post). The id came back as bison, but I just started looking at it again. I have been comparing it to Harry Pristis' gallery and I think it looks more like pleistocene camel. It measures about 60mm max length and 40mm max width. Found in the Brazos River. Just wanted to run it by the pros for a second opinion.