Two Fossil Crinoids (Onychocrinus And Platycrinites) - Indiana

This is two fossil crinoids from the Edwardsville Formation, Crawfordsville, Indiana, a 2.1" Platychrinites and a 2.0" Onychocrinus. Both show the calyx (body) and pinnules (feeding arms). A single section of stem is visible on Onychocrinus. The pinnules of Platychrinites are visible on the reverse side of the rock.

These fossils were prepared using skillful air-abrasion techniques under a stereo microscope.

It is believed that crinoids from the Ramp Creek Limestone were buried in sediment from nearby deltas during storms. The resulting siltstone deposits are soft enough that fossils can be extracted in exquisite, three-dimensional relief.

Crinoids, sometimes commonly referred to as sea lilies, are animals, not plants. They are echinoderms related to starfish, sea urchins, and brittle stars. Many crinoid traits are like other members of their phylum. Such traits include tube feet, radial symmetry, a water vascular system, and appendages in multiples of five (pentameral). They first appeared in the Ordovician (488 million years ago) and some species are still alive today.


Crinoids, sometimes commonly referred to as sea lilies, are animals, not plants. They are echinoderms related to starfish, sea urchins, and brittle stars. Many crinoid traits are like other members of their phylum; such traits include tube feet, radial symmetry, a water vascular system, and appendages in multiples of five (pentameral). They first appeared in the Ordovician (488 million years ago) and some species are still alive today.


Comes with acrylic stand.

#73- Platycrinites
#80- Onychocrinus
FOR SALE
$165
DETAILS
SPECIES
Onychocrinus ramulosus, Platychrinites hemisphericus
LOCATION
Crawfordsville, Indiana
FORMATION
Edwardsville Formation
SIZE
3.3 x 3.0" rock
CATEGORY
SUB CATEGORY
ITEM
#114380
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