Brachial valve
Anterior
Pedicle valve
Posterior
Profile
Parasprifier are well known from the Tichenor limestone (the top most member of the Ludlowville formation, just above the Wanakah shale) where they can be found embedded with the hard rock and can be difficult to extract. This specimen likely came from the Windom shale member of the Moscow formation as I found it in a somewhat recent pile of debris that came down off the cliffs from above the Tichenor limestone.
So the difference between this and Spinocyrtia is the more narrow profile and the lack of a valley along the middle of the pedical valve?
ReplyDeleteYes, I think that is correct. I differentiate between the two by size and shape. Paraspirifer is rounder (more sphere shaped overall) and fairly large. This specimen looks exactly like those from the Silica Shale: http://viewsofthemahantango.blogspot.com/2011/02/paraspirifer-from-silica-shale.html
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