Sunday, August 23, 2020

Kentucky Fossil Shells - Henry Nettelroth & Brachiospongia Fossil

Recently, I acquired a book entitled Kentucky Fossil Shells A Monograph of the Fossil Shells of the Silurian and Devonian Rocks of Kentucky by Henry Nettelroth 1889. I like to collect the old reference books to see the fossil plates even if I already have a digital copy. The copy I bought was discarded from the Adelbert College of Case Western Reserve University Library in Cleveland Ohio. It does not appear the school teaches paleontology classes anymore so no need for this book.

It just so happened that I got to see an Ordovician Period poriferan (sponge) fossil at the Field Museum of Natural History in Chicago, Illinois, USA last week. The museum display list it as Brachiospongia  sp. (490-443 million years old) and found Bridgeport, Kentucky. That same type of fossil is shown in the book. It is described as Brachiospongia digitata (Owen, 1857) on pages 29-30 and image listed in Plate XXXV figure 3 (image below). The fossil was first described by David Dale Owen in First Kentucky Geological Report Volume 2 page 111 as Seyphia digitata. The genus was later named by Marsh in 1867 in American Journal of Science and Arts, 2d series, Volume  44.

Next are two more figures from Plate XXXVI figures 1 and 2.

More images of another specimen at the museum.

It was a treat to see this fossil as I had only read about it before. They are very rare finds and only found in a few localities. The Peabody Museum at Yale have specimens can be seen here: and

Dan Phelps the president of the Kentucky Paleontological Society (KPS) gave a talk about these glass sponges to the Dry Dredgers fossil group in Cincinnati, Ohio, USA in 2008. I did not realize how many he had found and the large number of specimens that The Peabody Museum have in their collection.

Also it is brought up that a sponge fossil was found in Tennessee in the 1830s. It turns out that it was documented by Dr. Gerard Troost who I have written about before on this blog in 2009. The Field Museum of Natural History published Annotated Bibliography of Lower Paleozoic Sponges of North America by J. Keith Rigby and Matthew H. Nitecki in Fieldiana: Geology Volume 18, Number 1 on October 25, 1968 which lists references on sponge fossils. Find at this link.

The bibliography reports that Gerard Troost probably described the first fossil sponge from North America in 1838 but did not name it in Description d'un noveau genre de fossiles. Mem. Soc. Geol. France, 3, pt. 1, Mem. 4: pp. 87-96, pis. 9-11.