Crinoid
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Crinoids are marine invertebrates that make up the class Crinoidea. Crinoids that remain attached to the sea floor by a stalk in their adult form are commonly called sea lilies, while the unstalked fo
Crinoid on the reef of Batu Moncho Island
Stalked crinoid drawn by Ernst Haeckel
Stem, theca and arms of a "true" (stalked) crinoid (family Isselicrinidae)
Oxycomanthus bennetti (comatulid)
The Permian–Triassic extinction event, colloquially known as the Great Dying, was an extinction event that occurred around the boundary between the Permian and Triassic geologic periods, and with them
Crinoid
…four other extant echinoderm classes, all present-day crinoids appear to be descendants from a surviving clade that went through a bottleneck after the Permian extinction, at that time losing the feeding larval stage. The larva's free-swimming period lasts for only a few days before it settles on the bottom and attaches…
Permian–Triassic boundary at Frazer Beach in New South Wales, with the End Permian extinction event located just above the coal layer
Shell bed with the bivalve Claraia clarai, a common early Triassic disaster taxon
Sessile filter feeders like this Carboniferous crinoid, the mushroom crinoid (Agaricocrinus americanus), were significantly less abundant after the P–Tr extinction.
Lystrosaurus was by far the most abundant early Triassic land vertebrate.