Phylum: Echinodermata
Class: Crinoidea
Crown
Stalk
Pentaradial symmetry
Ossicles
Calyx
Pinnule
Holdfast
Benthic (some pseudoplanktonic)
Filter feeders
Ordovician to present
The heyday of the crinoids was the Palaeozoic, where they dominated shallow marine environments. Modern crinoids are exclusively deep marine, and the diversity of forms is far less than it was during the Paleozoic.
Were they victims of the increased grazing and predation pressure of the Mesozoic Marine Revolution?
youtube: modern crinoid behaving pseudoplanktonically. You can see the pinnules, crown and multiple stalks.
flickr: beautiful photographs of both living and fossil crinoids. Compare the levels of detail you can see, admire the colours, and spot the distinctive features that make these crinoids identifiable.
]]>Phylum: Echinodermata
Class: Crinoidea
Crown
Stalk
Pentaradial symmetry
Ossicles
Calyx
Pinnule
Holdfast
Benthic (some pseudoplanktonic)
Filter feeders
Ordovician to present
The heyday of the crinoids was the Palaeozoic, where they dominated shallow marine environments. Modern crinoids are exclusively deep marine, and the diversity of forms is far less than it was during the Paleozoic.
Were they victims of the increased grazing and predation pressure of the Mesozoic Marine Revolution?
youtube: modern crinoid behaving pseudoplanktonically. You can see the pinnules, crown and multiple stalks.
flickr: beautiful photographs of both living and fossil crinoids. Compare the levels of detail you can see, admire the colours, and spot the distinctive features that make these crinoids identifiable.