fossilized piece of bone? found in the Rio Grande

[katieincorrales]

Hi Everybody.. I'm not a fossil hunter (just an interested bystander), but my five-year old son found this while exploring the shallows of the Rio Grande near our home, just north of Albuquerque, New Mexico.  I'm 99% sure its fossilized and not just a bone.  It's about 9 cm by 5.5 cm.  You can see its smooth and curved on one side, and has a sort of sponge-like texture that would remind you of the inner part of a bone on the other. Any guesses on what it could be?  Thanks in advance for any input!

[Top Trilo]

One of these was on the forum about a month ago I think but I can't remember what it is. Like you though Im 99% sure its a fossil. I will be searching to hope to find out what kind of bone and then what kind of animal