Austin, TX Micro-fossils

[Jackito]

My faithful assistant and I have been sidelined with covid. But we felt good yesterday so we decided to explore a creek in Austin, Texas that has some Eagle Ford Shale exposed. It was a sunny, warm afternoon, and a cold front would be moving in at night.

 

At this location we've found quite a few teeth in the loose rocks strewn about. We're hoping to find mosasaur material but we've had no luck yet.

 

Our goal was to get a bucket of gravel to search for micro-fossils. I suspect most of the teeth are eroding from the underside of a large rock slab in the creek. We think this because my assistant stood on the rock causing the edge to break. He fell in the creek, flat on his back, and as he was getting up he noticed some exposed teeth. 

 

We collected a bucket of gravel by the rock slab and searched through a small bowl and found several small teeth. The teeth range in size from 1/4 to 1 mm. 

 

We also took a few rocks with some small teeth sticking out. It was a fun hunt after being stuck inside for the past week.

[old bones]

That looks like some very nice micro matrix!

[Jared C]

 

I'm pretty curious about this tooth. Do you have an ID? If not, do you have more angles of it?

Edited January 16, 2022 by Jared C

[Jared C]

Also, I should note: Mosasaur material is usually hard to come by in the Eagle Ford. If my memory is correct, the Eagle Ford in general encompasses the late Cenomanian and Turonian usually. The member you're on in particular is the South Bosque, and is Turonian. Mosasaurs only really began radiating in the late cenomanian, and though they had a few million years to diversify by the middle turonian already, they weren't nearly as diverse or widespread by that time as they were later. Looking in younger strata like the Ozan formation may give you better odds. I've heard of a few Ozan mosasaurs from central texas, and you're probably used to seeing the fantastic mosasaur finds from the NSR, which is Ozan as well.

 

You even have a shot at finding mosasaurs in the Austin Chalk, as @JohnJ has. Unless your particular interest is in early mosasaurs, and not just mosasaurs in general, other, younger formations like the Ozan and Navarro might give you better odds (and bigger teeth, as Eagle Ford mosasaurs were generally on the smaller end, compared to younger giants like Tylosaurus proriger or Mosasaurus hoffmani)

 

Don't be too discouraged though. Folks like @LSCHNELLE, @Uncle Siphuncle, and myself have found some cool mosasaur material in Eagle Ford before.

[ThePhysicist]

Nice teeth!

 

40 minutes ago, Jared C said:

I'm pretty curious about this tooth. Do you have an ID? If not, do you have more angles of it?

Looks like a ginsu intermediate:

 

^ https://www.jstor.org/stable/41309622

Edited January 16, 2022 by ThePhysicist