To celebrate the arrival of our new
Geology Curator, Neil Owen, Natural Science Curator Clare Brown
created the Lemon Drizzle Crinoid Cake – celebrating a mysterious
creature from the oceans.
Looks can be deceiving as crinoids are
animals not plants. They are members of the phylum Echinodermata.
This group of animals is made up of starfish, sea urchins, sand
dollars, sea cucumbers and sea lilies. First appearing in the fossil
record during the Early Ordovician, 480 million years ago and
survived to present day. They were prolific from the Carboniferous to
the Cretaceous with over 6000 species discovered.
The seas at this time would have been
teeming with crinoids gracefully swaying in the currents, almost
resembling plants in the breeze.
Unlike their relations, they developed
a unique body structure with a body (calyx) was covered in a flexible
membrane and was made up of interlocking plates, held aloft by a long
stem made of individually stacked plates (ossicles)to form a column. At the base of this column they attached themselves to the sea floor
with a root like structure (holdfast). On the upper surface of the
body they developed arms (brachials) with tiny filaments (pinnules)
to filter the passing water currents.
Unfortunately this body plan has been
lost in time as modern crinoids have evolved to resemble sea urchins
and are entirely mobile.
You can learn more about our Geology
Collections over on the #GeoBlitz blog.
By Lucy Moore, First World War Projects Curator
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