Unknown Invertebrate In Mid Mo Limestone

[cgroat]

I'm Carl, a new member of the forum as of a few minutes ago. I found this fossil in a piece of limestone in a dry creek bed about 15 miles N of Columbia, Missouri and have been unable to identify it.

I took it to a friend at MU, Columbia -- an invertebrate zoologist, but he could not I.D. the fossil. So, any suggestions would be appreciated.

Pictures attached. Thanks much.

[howard_l]

It is an Echinoid of some type maybe a crinoid

[Archimedes]

looks like a l Mississippian age partiale crinoid cup

[the tatter]

I agree, looks like a crinoid cup.

[Xiphactinus]

Definitely crinoid cup. Looks like the Burlington Formation, which would make that Mississippian age. Most likely Physetocrinus. It has those elaborate plates.

Edited August 31, 2015 by Xiphactinus

[Guguita2104]

Nice find!

For me it's a Physetocrinus crinoid calyx, like Xiphactinus said .

Another question:Howard the crinoids belong to the Echinoderms group, not echinoid (another type of echinoderms, wich includes sea urchins).

[cgroat]

It looks like a bit of consensus on it being a Crinoid calyx - likely Physetocrinus.

Much thanks for all the suggestions--this forum is a great resource.

[howard_l]

I was using the term Echinoid for Echinoderm as I would use brach for brachiopod, that is why I clarified it with crinoid. Most Geologist I know use the shortened version in discussions that are not formal.

[Guguita2104]

Howard, Echinoderm is a common name for the members of the phyllum Echinodermata, wich includes many classes of animals that have calcareous endoskeletons and radial symmetry, like the Echinoidea (sea urchins/cidaroids or echinoids ), the Crinoidea (crinoids),the Asteroidea (strafishes), the Blastoidea (blastoids) , the Cystoidea (cystoids)...So, echinoids isn't an abbreviaton for echinoderms.They are members of the class Echinoidea, and like crinoids belong to the phyllum Echinodermata.

Here are two links and a image to clarifie it:

http://www.ucmp.berkeley.edu/echinodermata/echinoidea.html

http://tolweb.org/Echinodermata

[howard_l]

I am very aware of the classificaton of Echinoderms and the Taxonomy of their "Phylum", Being a Geologist for over 40 years. Again I was using the term "Echinoid" as a catch all term for any Echinoderm that is not fully identifiable. Most Geologist I know do this also as it is shorter than Echinoderm. If this was a formal geological paper I would use Echinoderm, but in this informal setting most people here would understand the use of Echinoid.

[Coco]

Hi,

Sorry howard, not french people...

Coco

[Plax]

perhaps echinid? Not americans either coco!