27 June 2012

Permian fusulinids from west Texas

Posted by Callan Bentley

Today, I’m going to show you some monster-sized single-celled organisms: giant fusulinid forams from the western flank of the Franklin Mountains in west Texas, beyond El Paso. I saw these critters in February when I went on a field trip there led by Josh Villalobos of El Paso Community College.

Here’s the scene where we found these fossils (view is west towards New Mexico):

To prepare you to check out these things, examine this sketch I just drew. You will be looking at cross-sections through the architecture of the protist’s body:

Okay, now that your search image is primed, you can examine the photos:

When I’ve shown fusulinids on my blog before, it was to illustrate pressure solution. These Texas fusulinids don’t show any evidence of P-sol, but rather serve as exemplars of undeformed strain markers.

They are HUGE! Remember that each of these is a single-celled organism – one nucleus per critter. Unlike a lot of forams, these fusulinids are interpreted to have been benthic (bottom-dwellers), not planktonic (floaters).

Here’s a nice end-on cross-section:

Same sample, but rotated a bit to better catch the light:

Awesome. Everything’s bigger in Texas – even the extinct single-celled organisms!