These are incredible specimens, it’s quite common to find the little discs that make up the column. I’ve never seen fossilised Crinoids as intact as these before.
Whooa. I find those little cylinders/discs all the time at a local river. Knew they were called crinoids. But never knew what a crinoid actually was. Assumed it was some sort of plant or something. Insanely cool.
They actually still exist today!!! They're just more commonly called sea lilies - relatives of sea stars, sea cucumbers, and sea urchins, they're very fascinating creatures. Most fossil crinoids were thought to be immobile, but we now have video proof that they can pull themselves out of the substrate and either swim or drag themselves to a new spot.
Not quite - they tend to have appendages to hold on to whatever they're living on but if they're disturbed by a predator or if they're not getting enough food they can detach themselves from whatever they're latches on and swim/drag away to a better spot
Most crinoids today dont have a stalk as adults but the stalked crinoids have it to get higher in the water column to feed/reproduce, so they have a small bit of appendages at the end of their stalk that is under the substrate if it's soft mud or it latches on to a rock. As because of how ocean currents work, just 3 feet up from the seafloor is way more productive than the seafloor itself.
Fossil crinoids have been found to have stems over 40 ft long.
We have a great unit called the Onondaga that has a ton of disarticulated crinoids for days. I would have loved to see something like this during my studies.
Look up the Crawfordsville Crinoids, they’re amazing! They’re all over that region of indiana, I have a fossilized crinoid calyx that I found from that area.
In the shore where I live you can find tons if their arms in fragments. And yes, tons of discs. The largest I've ever found was like 2 cm long. This is an immaculate set of specimens.
These are the calyces (plural of calyx) specifically. Not the entire organism. Crinoids also have a series of disc like ossicles that stack up to form a stalk. With these discs being the most common fossil of crinoids
Several of them do still have their base stalks attached! You can see two great examples in the photo above, on the two in the center, that have their tentacles pointed upwards.
They (echinoderms in general) are the invertebrates most closely related to us, along with the hemichordata.
(Well, tunicates and lancelets are technically also invertebrates, but they share so many other characteristics with vertebrates that it makes more sense to think of them as an early branch of proto-vertebrates)
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u/EstablishmentReal156 1d ago
Crinoids apparently and WOW! *