Earth Discovery Day - August 2013

Today was Earth Discovery Day at the Falls of the Ohio State Park in Clarksville, Indiana. It is an event that focuses on educational activities for public. I have been volunteering over the last several years and it is a good feeling helping young students learn more about the mineral world around them while teaching about the fossil world of the past. Even though I have been really busy teaching, it is good to help out at an event like this.

The fossil pile was sparse in finds this year but the mineral pile while very dusty was a mountain of exploration for those willing to search for buried mineral treasure. The material is from a fluorite processing mill in southern Illinois that processed minerals from that area. Normally one sees four types of minerals: fluorite, barite, calcite, and sphalerite. The fluorite is usually purple, yellow or clear. Occasionally, green and blue fluorite will be found. A child found a nice fluorite cube corner shown in the first picture above. It has some nice purple phantom cubes that show through when held up to a light source.

Another child found a greenish-blue fluorite fragment while another found several aqua blue fluorite pieces. My challenge to visitors is to find pieces like this and usually about 4-6 specimens are found during my volunteer shift.

I was also told some material from China was processed there as well. So I am not sure what that might look like. A red or crimson colored rock was being found this year that was not seen in past years. It might be something from China. It is thought to be some type of reddish fluorite.

Fossils found were a number of brachiopods, corals, and snails from the Devonian fossil pile. The Silurian pile was being a bit more stingy. It did yield some nice brachiopods, a trilobite fragment, and a cephalopod fossil. Silurian Period Waldron Shale fossils are as shown: probably the tail (pygidium) of an Arctinurus sp. trilobite (I think it is upside down), next a fragment of a shell of a Dawsonoceras cephalopod, third is the index fossil of the Waldron Shale Eucalyptocrinus crassus crinoid calyx cup, and last an uncompressed Leptaena sp. brachiopod that has Cornulites sp. worm tubes on it.

Mesosaurus brasiliensis Aquatic Reptile Fossil

The aquatic reptile fossil pictured is a Mesosaurus brasiliensis  found in the Irati Formation of Brazil. It dates back 280 million years ago (Lower Permian Period). The museum display lists this fossil as one that shows the transition of reptiles to a freshwater environment. It also shows that the continents Africa and South America were connected since this creature's fossils are only found in those two places.

The reptile was thought to its narrow teeth rowed mouth was used to catch fish and other small aquatic creatures. It swam though the water using is long tail and paddle shaped limbs.

The fossil was loaned by Robert H. Osher family to the museum for exhibit.

Fossil on display at Cincinnati Museum of Natural History & Science as of August 2013.

Iansan beurleni Ray or Guitarfish-like Fossil

The sea ray or guitarfish-like fossil pictured is an Iansan beurleni found in the Santana Formation of Brazil. It dates back 100 million years ago (Lower Cretaceous Period). This fossil might also be known by the name Rhinobatos beurleni (1968) as seen on the Henskens Fossils web site. Refer to 1996 paper on subject The new genus Iansan (Chondrichthyes, Rhinobatoidea) from the Early Cretaceous of Brazil and its phylogenetic relationships by Paulo M. Brito and Bernard Seret.

The fossil is part of the Cincinnati Museum Center collection (accession number VP7189). It was gift to the museum from Charles Fleischmann.

Fossil on display at Cincinnati Museum of Natural History & Science as of August 2013.