Pycnocrinus
Pycnocrinus dyeri
Photo courtesy of Jack Kallmeyer
Scale bar is 5 mm
Pycnocrinus dyeri
MUGM 11264
scale bar 4mm
Pycnocrinus is distinguished by rays that bifurcate only once on the calyx, producing ten arms that then branch immediately to twenty arms. In Glyptocrinus, the rays bifurcate twice on the calyx, producing twenty arms that exit from the calyx.
Species
Pycnocrinus dyeri (Meek)
Occurrence: Fairview, Corryville
Reference: Ausich, 1996
Twenty arms on semi-globular calyx with stellate plates
Pycnocrinus pattersoni Miller
Occurrence: Economy
Reference: Dalvé, 1948
Formerly Glyptocrinus? pattersoni
Valid species?
Pycnocrinus subglobosus (Meek)
Occurrence: Corryville
Reference: Dalvé, 1948
Formerly Glyptocrinus subglobosus
Valid species?
