Sunday, May 17, 2009

Platystrophia Brachiopod with Cornulites

UPDATED: I originally posted this as a small horn coral attached to the shell but a series of anonymous comments set me on the correct course. What I thought was a horn coral was really a Cornulites. Thank you to the person(s) who gave me the correct identification.

All the heavy rains have provided great collecting at the road cuts outside the city. The Ordovician fossils that are the most common is the brachiopod. This brachiopod is a Platystrophia of some type. What I found interesting was this Cornulites that anchored itself in the groove of the brachiopod shell. It is thought to be a tubicolous annelid worm that orientated itself for feeding. Since this one was pointing toward the shell opening, it probably attached and grew there while the brachiopod was still alive.





This other Cornulites it placed in the opposite direction pointing toward the bottom of the shell.

Saturday, May 16, 2009

A 27 cm Silurian Cephalopod Casting

This cephalopod was found about 2 weeks ago protruding from a larger boulder. After about 15 minutes with a rock hammer and chisel, it was freed but it came out in several pieces. With the help of some cement the pieces were re-assembled into this approximate 27 cm (10.5 inch) Silurian period Dawsonoceras cephalopod.

Note the well defined ribbed pattern through the shell imprint. The growth lines have worn away. The size of this creature was impressive. It was one formidable predator in its day. I wonder why its beak imprints are not found on other fossils like trilobite shells? I would assume they would look like triangular shapes.

Found in Louisville Limestone in Jefferson County, Kentucky. This one belongs to someone else.




Here are some pictures of its other side with a small piece of coral still attached to the shell imprint.



Devonian Blastoid Elaeacrinus verneuili

This blastoid has seen better millenia but they are pretty rare for me to find in Devonian areas. This one was found in Clark County, Indiana (across the Ohio River from Louisville, Kentucky). It is probably an Elaecrinus verneuili (Römer [aka Roemer], 1851) found in Jeffersonville Limestone. It is about 2 cm by 1 cm is size.