azocrinids
Azocrinids are an extinct group of crinoids, marine animals related to starfish and sea urchins. They lived during the Paleozoic Era, primarily in the Devonian and Carboniferous periods. Azocrinids are characterized by their distinctive cup-shaped calyx, which was typically composed of a few large, fused plates. They possessed a flexible stem, also known as a stalk, which attached them to the seafloor or other substrates. Their arms were slender and branched, adapted for filtering food particles from the water column. Fossilized remains of azocrinids are relatively rare compared to some other crinoid groups, but their presence provides valuable insights into the marine ecosystems of ancient seas. The exact evolutionary relationships of azocrinids to other crinoid clades are still a subject of ongoing research. Their extinction likely occurred at the end of the Paleozoic, coinciding with major environmental changes and mass extinction events.