Sunday, April 3, 2011

Unidentified Fossil from Indiana

 This black fossil is somewhat of a puzzle.  It was found in the Jeffersonville Limestone of Clark County, Indiana, USA.  This layer would be Middle Devonian (approximately 390 million years ago).  It is mixed in the remains of crinoid stems. Length is about 2.5 cm and it branches several times with maybe 18 offshoots.

Is it some sort of graptolite or plant remains washed in from another area?


Paleonut said...

It reminds me of algae... might be a place to start.

Kentuckiana Mike said...

I took your advice and looked at algae fossils. The Index Fossils of North America (1944) shows an image on plate 301-21 of a Buthotrephis gracilis (Hall,1847). The fossil looks similar to the one shown in this posting. It is a Silurian fossil and I am not positive the rock I have is Devonian.

Thanks for the help!