Tylothyris mesacostalis brachiopod from the Chemung group of New York

A new spirifirid type brachiopod in my collection is this Tylothyris mesacostalis which comes from the Upper Devonian, Chemung Group near Painted Post, NY. The specimen is a internal cast of the pedicle valve with some other brachiopod casts around it. What I can see is a valve that is wider than it is long, is deep and has a straight interarea on the posterior. The "beak" that you can see at the top of the fossil is very indicative of Spirifer type brachiopods. That is where the pedicle muscle was located with the empty space on either side of the "beak" representing portions of the shell that dissolved away.

Pedicle valve

Anterior

Profile

Posterior

The Chemung Group is a broad term used to describe a series of rocks that have a similar fauna that existed in the upper Devonian. It consists of many different formations but the label I recieved with the specimen does not have anything more specific other than the locality. Given Painted Post as the "location" of the fossil, it's a little west of Corning, NY, I can look at a geologic map and see that the possible source rocks could be the Nunda Formation, West Hill Formation or Gardeau Formation. All of those formations crop out in the nearby vicinity of Painted Post but as I have no experience collecting in them I can't narrow down the source formation. I received this fossil via trade with someone who had purchased it at an open house sale at the Rutgers Geology Museum.

Hydnoceras bathense fossil glass sponge from New York

Below are some pieces of a glass sponge called Hyndoceras bathense from the upper Devonian (Fransian stage) of New York. It comes from rocks that are part of the Chemung Group but I don't have more specific formation or layer info. Sponges are somewhat rare the find fossilized as they are composed of many tiny spicules that are held together by the fleshy parts of the body. When they die the fleshy parts decay and all the spicules get scattered. For the specimens below to have been preserved they must have been rapidly buried during a storm event or an underwater landslide.

The first two specimens are just one side of the sponge. Either the fossil split or was not preserved on the other side.

Specimen #1

Specimen #2

Specimen #3 is fully complete and 3-dimentional (except for being compressed by the sediments)

Specimen #4

I purchased these specimens at my local Delaware Valley Fossil Society club show in April.

There is an impressive piece from West Virginia with multiple specimens that can be seen on the West Virginia Geological and Economic Survey page.