Trilobite Fragments? Some Very Small.

[Mignoffo]

Post #1

We picked up this cool hash plate along the Rock River in Ogle County, Illinois. this is Ordovician. Mifflin formation of the Platteville group. We are trying to figure out how many species of trilobites occur in this piece. We have identified at least three thus far.

First pic in order. Extremely tiny fossil. You will notice it right to the right in the "y" of the small bryozoan - not the large (~2mm) pygidium off to the left. s far as the micro-fossil off to the right - we are not sure if this is a pygidium of a tiny trilobite or a small clam or brachiopod.

Next three pics (of same fossil) we believe is a free cheek of an Isotelus, or Basiliella. Amazing that Caleb is still the finest resource for learning which trilobites inhabit this rock, then for trying to piece them out for an ID.

I will make an additional post for a few more.

[Mignoffo]

This next trilobite we believe is Gabriceraurus mifflinensis - again, not the obvious pygidium (of what we believe is Calyptaulax) the larger skeletal looking remains.

Last two pics. Is this an invert trail? maybe gastropod or bivalve?

Thanx!!!

Matt/Alan

[Mike Pocock]

Hi, Nice finds thanks for sharing.

Regards

Mike

[Raggedy Man]

Hello, the first photo above is a trilobite pygidium. The rest of the photos in that post could be the isotelus remains. The second group photos do not remind me of a trilobite, but rather a crinoid. The rest are definitely trace fossils. I have a similar piece from the Vulcan quarry. Nice finds!

Best regards,

Paul

[Guguita2104]

Nice finds!

I see some fragments of Bryozoan fossils (Paleozoic reef "constructors" that live in colonies.Each member is called a zooid).I see ,also, a trilo pygidium and some blastoid (echinoderms similar to crinoids that lived only in the Paleozoic era) stems and maybe calyxes.

[ZiggieCie]

Very nice finds. Small but still important.

[Guguita2104]

Oh, I forgot to say that the second photo of the second group seems to me ichnofossils.

[PennyT.]

There sure is a lot going on in this small piece of real estate. Like you, I miss Caleb with every trilobite post from the Midwest.

I agree with the Isotelus free cheek fragments and can see why the spine-like fossil is suggestive of Gabriceraurus. Wish i had it in my hand...here is a trilo mold I found to compare to your skeleton-like one. Sorry for the poor photo quality.

Fun share, thanks.

Penny

Edited September 30, 2015 by PennyT.

[PennyT.]

From Caleb's Photo Gallery

Edited September 30, 2015 by PennyT.