Here's a hyocrinid "pinwheel" crinoid form the Okeanos dive to Indonesia! (INDEX-SATAL 2010)
For those who might not be familiar with stalked crinoids, they are the ancient ancestors of modern day feather stars (aka comatulid crinoids).
Stalked crinoids are fundamentally composed of three main regions: the calyx (or cup), arms and stalk which is very nicely illustrated by this diagram from the Field Museum in Chicago!
Stalked crinoids feed on food particles in the water column using their arms which they move down to the mouth located at the top of the calyx (or cup). The stalked and unstalked forms have an unusual relationship which you can read about in an earlier post here.
Let's start off with this gorgeous one called Acanthocrinus rex! from the lower Devonian of Germany. This image was reported by crinoid scientist Hans Hess as "certainly one of the most beautiful crinoids ever found.." Sadly, this specimen was lost in World War II.
|This image from: https://geo-ebooks.tumblr.com/post/127610816184/acanthocrinus-rex-j%C3%A4kel-from-the-lower-devonian|
Here is: Onychocrinus ulrichi a fossil crinoid from the Edwardsville Formation, Lower Mississippian; Crawfordsville area, Montgomery County, Indiana, USA.
Christmas star theme for #FossilFriday ? Acanthocrinus spinosus from the Devonian Windom shale of New York. pic.twitter.com/KejobiKyJR— David Clark (@Clarkeocrinus) December 18, 2015
Still searching for info about my Acanthocrinus spinosus from Dev. Windom shale in NY. #crinoid #fossil pic.twitter.com/CdWOSMWt— David Clark (@Clarkeocrinus) May 2, 2012