Crinoid

cf. Plicodendrocrinus proboscidiatus

• Ordovician
• Dunleith Formation, Galena Group
• Iowa or Minnesota, USA

Size: 1.5 cm crown

Identification based on "Brower, J. 1995. Dendrocrinid Crinoids from the Ordovician of Northern Iowa and Southern Minnesota" and "Billings, E. 1857. New species of fossils from Silurian rocks of Canada".

Traits consistent with the description are the pentalobate column, narrow radial facets, isotomously-branching uniserial arms made of brachials which are tall and narrow and bear sharp aboral sides, and an ornamented anal sac. This specimen is likely immature which explains the near-absence of calyx ornamentation, though even in mature specimens the ornamentation is subtle for this species.