Wednesday, June 17, 2009

Biodiversity on a Devonian Brachiopod

Here is a brachiopod found in the Devonian layer in Clark County, Indiana. I am guessing the brachiopod could be Mediospirifer sp. with some sort of encrusting bryozoan and Aulocystis coral on one side. The other side of the brachiopod are more Aulocystis corals and an inarticulate brachiopod that could be Philhedra crenistriata or Crania multistriata. Researching all the fossils on this specimen I used a couple of resources. The brachiopod brochure found on the Falls of the Ohio State Park website gives a list of fossil brachiopods found in Clark County near the river. A new source I just found was the Friends of the UMMP (University of Michigan Museum of Paleontology) database with over 1000 images for fossil images. They have an image similar to this one with Mediospirifer brachiopod, Petrocrania hamiltoniae inarticulate brachiopods, and Aulopora corals.

Close up of the inarticulate brachiopod. Notice the lines radiating out from the center.



Encrusting bryozoans over part of the shell.

This corals are pointing up so all of these creatures may have been attach while the brachiopod was still alive.

3 comments:

Shamalama said...

Wow, what a great piece. I love combo pieces that show paleoecology. I think the inarticulate brach on your mediospirifer is Philhedra based on pics from the Dry Dredgers site: http://drydredgers.org/rons_philhedra.htm

Fossil Detective said...

Thanks for the link, they have some nice pictures. I did not think to look on the Dry Dredgers site since this was a Devonian fossil. It looks like the Philhedra spanned from the Ordovician to at least the Devonian periods.

This specimen is a candidate for sandblasting. The Aulocystis corals I find always seem to have matrix in them!

I have a future Devonian brachiopod posting that has a nice story to tell as well.

Shamalama said...

You know, I hadn't thought about the difference between Ordovician and Devonian when I wrote earlier. After some further research I found this link: http://deepblue.lib.umich.edu/bitstream/2027.42/48437/2/ID285.pdf which discusses inarticulate Brachiopods from the Devonian Silica Shale. So the Genus Philhedra has existed from the Cambrian to at least the Devonian. I can't find any other info on when the Genus went extinct but it's likely that they didn't last past the Carboniferous as that is when most Brachiopods were wiped out.