Wednesday, August 26, 2015

Coelospira concava or Atrypina imbricata brachiopod from the Kalkberg formation of New York

This is the last fossil that I am profiling from the Kalkberg formation for now. I'm very surprised at the number of species that I found from this formation considering that I have only visited it once and only at a single roadcut. The honor of being last goes to a mystery brachiopod. The shell is semielliptical with a convex pedicle valve and concave brachial valve. Both valves have very strong plications but no fold/sulcus structure. There are prominent growth lines visible towards the edges of the margins. The pedicle valve appears to have a beak and umbo.

Pedicle valve
Brachial valve

Hall lists two species that look similar to the above fossil, Leptocoelia concava (since updated to Coelospira concava) and Leptocoelia imbricata (Since updated to Atrypina imbricata), in the "Paleontology of New York", Vol 3, pg. 245-246, pl. 38, fig. 1-13. Based on the pictures in that volume I am inclined to call my fossil Atyrpina imbricata due to the presence of the growth lines which is indicative of the species.

This specimen was collected from the Kalkberg formation (Devonian, Lockhovian to Pragian stage) at a roadcut near Schoharie, NY.

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