Mystery echinoderm from the Verulam formation

Below are some pictures of a mystery Echinoderm from the Verulam/Bobcaygeon formation. I am not entirely sure of the formation this comes from as it was found in an area that was close to the boundary of the two units.

It was found a couple of years ago and cleaned by an expert but there it not much there to go on. I posted these images to a group on Facebook that is frequented by knowledgeable people who have collected for many years from the Verulam and Bobcaygeon formation. The only possibility that was suggested was that it could have been part of the central body of a starfish. The presence of many small plates does make it seem like an echinoderm and starfish have lots of small plates as part of their bodies so I think this is as close as I'll be able to get to figuring out just what this was. For reference, the fossil is about the size of a US quarter.

I collected this fossil in 2017 at the James Dick quarry near Gamebridge, Ontario. The Verulam and Bobcaygeon formation is late Ordovician in age, Katian/Mohawkian stage.

Cupulocrinus jewetti crinoid from the Bobcaygeon Fm.

This is a partial Crinoid from the Bobcaygeon formation in Gamebridge, Ontario, Canada. I found it a few years ago on a field trip and a friend, Malcolm, cleaned it up for me. The crinoid is named Cupulocrinus jewetti and this is a pretty good example. The stem and some arms are missing but otherwise it is a decent specimen.  It is one of the few articulated crinoid specimens that I have found myself.

The Bobcaygeon formation is Ordovician in age (late Ordovician, Katian/Mohawkian stage).
I used William Hessin's book "South Central Ontario Fossils", 2009, Self Published, pg. 244 to help identify this fossil.

Syringocrinus paradoxicus carpoid plate from the Verulam formation

A number of years ago I picked up a large plate of shaly limestone at the James Dick quarry in Gamebridge, Ontario. It comes from the Verulam formation and I knew it was a special find as I could see what looked like crinoid stems on it but with slightly different shapes to the stems. It turns out that after a good cleaning by my friend Malcolm the crinoid stems are actually carpoid stems. Carpoids are odd echinoderms that are cousins to crinoids. These particular fossils are called Syringocrinus paradoxicus and are fairly rare to find. There are no complete specimens on the plate but plenty of stems and calyx plates scattered about. 

As a bonus, there is a small Archaeocrinus sp. crinoid off to one side of the plate. Thanks go out to Kevin B. for the ID on this small fossil (the calyx is maybe 1cm in width).

The Verulam formation is Ordovician in age (late Ordovician, Katian/Mohawkian stage).

Hardouinia kellumi echinoid from the Pee Dee formation

Echinoids are cool critters that come in two basic flavors, regular and irregular. The regular echioids are the ones you see in aquariums and on nature shows with the long spines crawling along the bottom of the reef. Irregular echinoids are more often partially submerged in the sediment and do not have large showy spines.  Hardouinia kellumi is an example of an irregular urchin and could also be known as a sea biscuit.  The specimen below is from the Cretaceous ages sediments at Rocky Point Quarry in North Carolina. It comes from the Peedee formation which is dated to the late Maastrichtian (66-67 mya)

Adaptical surface

Anterior

Left profile

Posterior

Right profile

Adoral surface

Macraster sp. echinoid from the Duck Creek formation of Texas

Not only does the Duck Creek formation have ammonites, it has some echinoids as well. I found a couple of nicely inflated specimens of the irregular echinoid Macraster. I sent pictures of my find to a friend in Texas, who is familiar with the Duck Creek formation, and he said they could be either M. elegans or M. washitae. Macraster has a suboval shaped test with a sub rectangular cross section. The adapical surface has the typical five arm imprint of the ambulacra which is where the feet of the animal would have extended from. There is a small oval shaped opening in the posterior of the test called the periproct which is where the anus of the animal would have been. On the underside, or adoral surface, is the opening for the animals mouth called the peristome.

When I was a kid I called echinoids with this shape "sea biscuits".

Specimen #1 is a little water worn.
Adapical surface

Posterior

Left profile

Anterior

Right profile

Adoral surface

Specimen #2 is missing some of the test on the adoral surface
Adapical surface

Posterior

Left profile

Anterior

Right profile

Adoral surface

The only other Echinoid evidence that I found was this isolated piece from a regular echinoid.

The above specimens come from the Duck Creek formation which is Cretaceous (Albian stage) in age.

Coenholectypus planatus echinoid from the Walnut formation of Texas

This round echinoid is Coenholectypus planatus echinoid from the Walnut formation of Texas (Cretaceous, Albian stage). It is one of many that I have received from a friend who collects in the Lone Star State. The test is round when viewed from the dorsal or ventral sides and shaped like a dome when viewed from the sides. In like it would have been covered with many small spines, the bases of which you can see preserved. I think this is considered a "regular" echinoid due to it's shape. Based on the shape of the test and small spine bases I think that C. Planatus would have lived in the littoral zone in rocky and sandy areas.

Adoral surface

Profile views

Oral surface

Edriocrinus policiformis crinoid "cup" from the Kalkberg formation of New York

These little Edriocrinus policiformis crinoid cups are somewhat common in the Kalkberg formation of New York. They are a pretty good indicator that the rocks are lower Devonian in age. These fossils are just the base of the crinoid calyx (which may have been free floating) and there were other plates attached that would extend the calyx up to the arms. They are fairly easy to ID as they look like small gumdrops that are hollow.

Specimen #1  - The first three photos in this sequence is viewing a profile of the calyx as I rotate it 120 degrees between shots.

This is the "oral" side of the cup.

This is the anterior or bottom of the cup.

This specimen is still attached to matrix and is a little taller than the previous specimen.

The Edriocrinus policiformis fossils I found in the Kalkberg formation compare nicely to those that I found in the Licking Creek formation of Virgina as seen here. The Virginia specimens are a little larger and "more complete" but have been replaced with silica. The Kalkberg formation is concurrent with the Licking Creek formation. Both are dated to the Lockhovian-Pragian stage of the lower Devonian. I found all the above specimens at a roadcut near Schoharie, NY.