Bovine Jaw

[truceburner]

This section of jaw was found a few months ago in the cut bank of a creek in Austin, TX, nearly 15 feet below the top of the soil. I spent an hour removing the jaw from the overburden, and thought I got everything that was there. A recent return to the spot proved me wrong - much of the remainder of the skull is now visible, though I was unable to collect it at the time.

If it's a modern bovine jaw, I will let the creek have it. But if it's something more interesting, it may be time to put the waders back on. Only the depth of the soil above it made me think it could be old. What do you think?

[MammothPaleoGuy]

I know proboscideans better than I know artiodactyls, but I think it's Bison not Bos. I'm not super confident, but that's the way I'm leaning. Doesn't mean that it isn't geologically recent, of course, but it's still more interesting than your average cow. More significant I think is the facies change. The upper 15' look like typical floodplain deposits, but your mandible is at the very top of a river gravel. The time for a river channel to deposit gravel, shift its banks, fill with flood silts, shift back and erode back through the river gravel is probably pretty significant, just as you imagined. The best plan is probably to excavate the skull, provided you can do so legally. If you need help, drop me a line -- I live in Georgetown.

P.S. Based on Toennies master's thesis of 1973, your critter was pretty elderly -- between 5.5 and 9.5 years old.

[RichW9090]

It's certainly Bison or Bos. You'd need the skull to know for sure. At that depth, it's likely Bison.

[truceburner]

Thanks, gentlemen. Here's what I found from searching Toennies and bison: http://nmita.iowa.uiowa.edu/paleo/bison.htm

[RichW9090]

There are several schemes for aging Bison mandibles. Basically they provide a set of relative ages, and not absolutely certain ages in years, although they are often expressed that way,. In the case in your link, they are assumed to be Bison based, it would appear, on the geological context.

Rich

[truceburner]

Good points, Rich. I'm more interested in how much time has passed since it was alive than in how long it lived. I'll definitely be going back to see what other bits I can find.