Marsupites

Marsupites is an extinct genus of crinoids from the Santonian stage of the Late Cretaceous.
Biostratigraphic significance.
The International Commission on Stratigraphy (ICS) has assigned the extinction of "Marsupites testudinarius" as the defining biological marker for the start of the Campanian stage of the Late Cretaceous, 83.6 ± 0.2 million years ago.
Distribution.
Fossils of the genus have been found in: