Need a little help

[Stingray]

Endoceras cancellatum my conclusion IMO

[DPS Ammonite]

Stingray, a clarification; you say it has "convex/ conical shape on both ends." That shape is because of wear and erosion. When I mentioned concave/ conic I was interested if you think the separations between each disk are planar like a stack of coins or if the separations are rounded like a stack of bowls. To me the separations look planar like a stack of crinoid disks. The radial lines along the plane of separations also like those of crinoids.

Here’s a photo of Endoceras cancellatum. Notice how the separations between each “disk” or chamber are curved along the surface of each septa. I don’t see any curved surfaces between each disk in your piece. Do you?

Something else to look for to help with and ID. Do you see any shiny cleavage planes in the disks that might indicate that it is a calcite crystal. In crinoids each disk is a crystal of calcite with distinct cleavage.

[TqB]

Stingray, a clarification; you say it has "convex/ conical shape on both ends." That shape is because of wear and erosion. When I mentioned concave/ conic I was interested if you think the separations between each disk are planar like a stack of coins or if the separations are rounded like a stack of bowls. To me the separations look planar like a stack of crinoid disks. The radial lines along the plane of separations also like those of crinoids.

Here’s a photo of Endoceras cancellatum. Notice how the separations between each “disk” or chamber are curved along the surface of each septa. I don’t see any curved surfaces between each disk in your piece. Do you?

Something else to look for to help with and ID. Do you see any shiny cleavage planes in the disks that might indicate that it is a calcite crystal. In crinoids each disk is a crystal of calcite with distinct cleavage.

I agree with all that. Without the specimen in hand, I was assuming they were like stacked bowls but if they are planar discs (which it looks like) then it's pretty definitely crinoid.

Edited August 5, 2016 by TqB

[Stingray]

This is the stock photo I used that led me to my conclusion . I have enhanced the section that brought me to my selection of this species, but hey it could just be a flattened out Crinoid after all. Maybe I'll stop by the Geology Department at the College.........

[Guguita2104]

Maybe a very worn fossilized rugosan coral (Rugosa order).

Here it's a pic for comparison:http://www.therockgallery.co.uk/ekmps/shops/therockgallery/resources/Design/rugose-corals.jpg.

Regards,

Edited August 5, 2016 by Guguita2104

[Stingray]

Thanks to everyone for the imput. I,m gonna add it to a few I need to take to the college for definitive ( loosely) id