Crinoid ID from Keyser formation

[Shamalama]

Hi all,

 

Another couple of mysteries that I found at an old quarry near Mapleton, PA and are from the Keyser formation which is thought to straddle the boundary between the Silurian and Devonian periods. The layers they were found in were close to layers of the Tonoloway formation which is Upper Silurian in age.  I found one item that I believe is a Mariacrinus pachydactylus based on the Paleontology of New York, Part 3, Vol 2, Plate 3.  It's been preserved by a black colored Chert but I don't want to acid etch it any more that I have (about an hour in vinegar).

 

 

 

The other oddball is this UFO shaped specimen. I've found similar examples before but I ruined any chance of seeing detail on the surface by soaking them in vinegar. This is the first example I've found since then. Close examination with a lens and microscope does not show any detail so it may need to be cleaned a bit more.  The "Bottom" has a nick in it or maybe it was where a stalk attached?  Any thoughts?

 

 

Thanks for looking!

[Fossildude19]

Great finds, Dave!

Maybe @crinus  can weigh in?

[FossilDAWG]

The second Fossil might be a Scyphocrinus float.  These were root structures that were filled with gas and allowed the crinoid to float.  They are common (or so I have read) in the Upper Silurian Decateur Formation and the Lower Devonian Ross Formation in Western Tennessee, so they certainly could occur in the Keyser.

 

Don

[Shamalama]

1 hour ago, FossilDAWG said:

The second Fossil might be a Scyphocrinus float.  These were root structures that were filled with gas and allowed the crinoid to float.  They are common (or so I have read) in the Upper Silurian Secateur Formation and the Lower Devonian Ross Formation in Western Tennessee, so they certainly could occur in the Keyser.

 

Don

Don,

 

That is not a bad idea. Perhaps they didn't get as big as they did in other areas? The only specimens I've seen of the floats are about the size of baseball or softball.

[fossilnut]

Scyphocrinus loboliths are found in the Keyser formation at the type locality in WVA. The ones I have seen are more flattened rounds maybe we are both saying the same thing-UFO shaped. See post 12/5/16 Scyphocrinus loboliths