Tuesday, April 27, 2010

Bordenia knappi


A horn coral named after William Borden whom Borden, Indiana was also named.  Mr. Borden made a fortune mining silver in Colorado in the late 1800s and returned to Indiana.  His geology collection became very large and after his death transferred to the Field Museum in Chicago.  He might be best known for creating the Borden Institute and Museum to help educate youth in the southern Indiana area.

This horn coral is actually two clustered together but 90 degrees out of phase.  It is called Bordenia knappi (Hall, 1882) and found in the Speed Member of North Vernon Limestone.  It was found in Clark County, Indiana, USA and the coral existed in the Middle Devonian Period (Eifelian).

The species was named by Dr. James Hall in the 35th Annual Report of the State of New York, page 438 in 1884. It was named in honor of Professor Hall's friend long time fossil hunter Dr. James Knapp of Louisville, Kentucky, USA.

The genus Bordenia was named by long time fossil collector from New Albany, Indiana, USA George K. Greene in 1903 in Contributions to Indiana Palaeontology Volume I, page 99, plates 31 figures 4-11. He named it for William Borden who he later sold his collection to.

Monday, April 26, 2010

Romingeria umbellifera

Middle Devonian Period coral called Romingeria umbellifera. It was found in the Jeffsonville Limestone of Clark County, Indiana.


Enhanced image from Kentucky Fossil Corals - A Monograph of the Fossil Corals of the Silurian and Devonian Rocks of Kentucky (1885) by William J. Davis, Plate 75, Figure 12.  Find on-line at KPS website of Don Chesnut web adaptation.


Sunday, April 25, 2010

Fossil Prep

A while back, a friend dropped this Mississippian Period blastoid in matrix off during his trip to Louisville. He had been collecting in the Indian Springs Formation of Crawford County, Indiana.  The fossil is about as big as a marble.

So these first two pictures show the blastoid in the rock matrix. I decided to extract the blastoid with the Dremel engraver. The matrix was pretty soft and flaky.



I stopped to photograph the fossil plate with the engraver lines. Matrix has broken off revealing more of the blastoid theca.




Eventually the vibration of the engraver broke the blastoid free for its rock tomb. Now I need to sand blast it to reveal the top detail.  Not the white marks where I probed to see if any more matrix would break away.  Decided it might damage the fossil to proceed down this path.