Melonechinus Sea Urchin Fossil

This fossil was seen at the New Harmony Indiana USA Working Men's Institute Museum & Library in June 2020. It was identified as a Melonechinus sp. (Meek & Worthen, 1861, p. 396) from St. Louis Limestone. The fossil dates to Mississippian Period (340-330 million years ago) in the Meramecian series. Limestone named by George Engelmann in Remarks on the St. Louis Limestone: American Journal of Science, series 2, volume 3, pages 119-120 (published 1847). Specimen accession number WMI 310.4.

There appears to be a second echinoid fossil on display as well but was not labeled. This one was more intact. The case label read "Mr. James Sampson, 1806-1890, was a saddler, a storekeeper and McClure agent. When he retired in 1858, he followed his fancy for collecting things, natural history mainly along the Wabash River and cut off river." The case is full of nice fossils but almost none of them are labeled. The fossil looked to be about the size of a grapefruit.

Acrocyathus Mississippian Fossil Coral

These rugose coral fossils were found in Floyd County, Indiana in the St. Louis Limestone.  This limestone dates back to the Middle Mississippian (Carboniferous) period.  The corals appear to be Acrocyathus floriformis? also referred to as Lithostronchia or Lithostrotion or Lithostrotionella. These coral fossils also are found in Kentucky, Missouri, West Virginia, and maybe Alabama. Thanks to Alan for help with identification.

See a Lithostronchia specimen on the KYANA Geological Society web site: CLICK HERE

UPDATE (2019-06-15): website link below has changed to this: http://www.uky.edu/KGS/fossils/fossil-coral-rugose-corals-mound-shape.php

Learn more at the Kentucky Geological Survey web site: http://www.uky.edu/KGS/fossils/rugosecolonial3.htm

See other Lithostrotion corals on Plates XXXVI and XXXVII: CLICK HERE