Jump to content

Ordovician Platteville Fm. Bryozoa


Caleb

Recommended Posts

I see these every once in a while, but I can't seem to locate any information on them. The shape is fairly consistent involving a tapering "cone" with a bulbous end. I'm hoping with such a distinct shape, someone with knowledge of Byrozoa may be able to assist me with a possible genus or family.

Middle Ordovician, Blackriverian

(similar in age to the Bromide Formation of Oklahoma)

Platteville Formation, Mifflin member

Southwest Wisconsin

All pictured measure around 3cm

These are 3 different specimens on the same hash slab:

post-3840-0-97809600-1358468184_thumb.jpg post-3840-0-11270600-1358468187_thumb.jpg post-3840-0-18225300-1358468189_thumb.jpg

Thanks,

Caleb

Link to comment
Share on other sites

Maybe, Lyopora?

"Absence of evidence is not evidence of absence"_ Carl Sagen

No trees were killed in this posting......however, many innocent electrons were diverted from where they originally intended to go.

" I think, therefore I collect fossils." _ Me

"When you have eliminated the impossible, whatever remains, however improbable, must be the truth."__S. Holmes

"can't we all just get along?" Jack Nicholson from Mars Attacks

Link to comment
Share on other sites

I'm having trouble finding references to Lyropora being in the Middle Orodovician/Blackriverian. Does anybody have a copy of the paper: "Bryozoa From The Ordovician Bromide Formation, Oklahoma" Loeblich, 1942?

The "bulb" at the end does not seem to be a pathology/injury. The vast majority of them I have seen in the field have the bulb and they never seem to be part of a larger colony, just the single "cone". The Paleodb taxonomic list for the Mifflin lists 6 bryozoa, but I have the feeling that just scratches the surface:

Amplexopora winchelli

Diplotrypa catenulata

Eridotrypa subtilis

Heterotrypa sp.

Homotrypa sp.

Orbignyella sublamellosa

Thoughts, ideas, suggestions?

Link to comment
Share on other sites

Escharopora sp. maybe?

Link to some specimens I found in the Verulam fm. of Canada

-Dave

__________________________________________________

Geologists on the whole are inconsistent drivers. When a roadcut presents itself, they tend to lurch and weave. To them, the roadcut is a portal, a fragment of a regional story, a proscenium arch that leads their imaginations into the earth and through the surrounding terrain. - John McPhee

If I'm going to drive safely, I can't do geology. - John McPhee

Check out my Blog for more fossils I've found: http://viewsofthemahantango.blogspot.com/

Link to comment
Share on other sites

Caleb,

Do all the specimens have a crushed look? I'm wondering if the shape comes from something that was encrusted? There are only a few ramose bryozoans with hollow branches and even then they are still thick enough not to have that crushed look I see in your specimens. The bulbous end on a tapered form makes me think of some cephalopods and their protoconch tips. There is a fairly common bryozoan genera in the Upper Ordovician called Spatiopora. It has numerous species of various forms. Just a thought.

Erich

Link to comment
Share on other sites

The specimens shown here are crushed with the third specimen being the most inflated. I have seen inflated specimens, but since they're bryozoa I generally leave them lay. Perhaps this spring I will collect a couple better examples to share. The uniformity of the shape and size of the many specimens I've seen in the field leads me to believe that they are not an encrusting bryozoa. A type of Escharopora does seem like a possibility. 2 species of Escharopora have been described in the 1893 MN Geological Survey paper.

The loan process for the thesis paper that Piranha linked to has been started, so we'll see if I can get my hands on that.

Edited by Caleb
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...