Any herpetologists here?

Photographed at Martin Park in Oklahoma City. I've never seen this species before. Can't find it in google. Anyone know what it is?

I don't know unless it is a Common Snapping Turtle, which is the only one I could find with speckled skin, but the head seems a bit small, and the scutes along the margin of the shell is wider in your shot.

I'm not a herpetologist.

Definitely not a snapper. I took the picture back to the folks that run the park, they've seen the turtle before, but don't know either. I'm gonna call it a new species and name it Frog Faced Spot Headed Turtle.

Could it be a western pond turtle? Or maybe a mut? Some kids pet turtle got loose and decided to get busy at the local pond. . . . . .

It really looks like it could be. At least some of the pictures resemble it. Closest thing I've seen so far. Range is completely wrong, but range doesn't mean much anymore, the way folks drag things around with them.

Some sort of slider hybrid maybe. Could be a male judging by the length of the nails on the forelimbs.

You should try some local resources like universities, wildlife protection agencies, etc. If it is an introduced species they would appreciate knowing about it and be happy to ID it.