Iowa River find 2 unsure

[Dereynes]

This is one I’m not really sure about this vertebra, or this leg bone?... both are very heavy for their size!

[Darbi]

I'm not good at identifying the bones, but these look like mammal bones. Since you said it's really heavy for its size, it's probably mineralized, so probably from Pleistocene. I'm sure others will chime in.

[Darbi]

Did you try the flame test? If not, burn a part of it to see if it give off the burnt hair smell.