Annelida, Order Turrilepadomorpha, Family Plumulitidae
or Chordata (?)
Phylum Cnidaria, Class Scyphozoa
Time: Lower Ordovician
mm = 1 inch): Macaheridians: 40 mm by 16 mm and 37 mm by 14 mm Carpoids
17 mm and 15 mm across Conularids: 20 mm by 12 mm and 20 mm by 15 mm
on a 160 mm by 110 mm matrix
Fezouata Formation, El Kaid Errami, Morocco
This is a fine example of an Ordovician Morooccan sea floor assemblage
containing Machaeridians (armored worms), carpoids, and conularids.
The Machaeridians are a little-known group of skeletal marine
fossils that ranged in time from the Ordovician to the Permiian.
Until recently the assignment as to phylum was controversial
until the discovery of a Moroccan specimen with delicate preservation
was made some 4 years ago which affirmed the assignment as armored
annelid worms. Typically these are found as only dissociated
parts. To my knowledge these are the first near complete
examples ever offered. The ribbed specimens are conularids. Conulariids
have been a subject of speculation for over a century and a half.
They ranged from the Middle Ordovician to the Triassic. Exactly
what they were is still not settled. Because of their four-fold
symmetry, they have often been placed in the Cnidaria. However,
their skeleton was very different from anything known in the
Cnidaria, and they may represent a separate, extinct phylum.
Finally, there are a couple of carpoids present. The carpoid
body was supported by a skeleton of calcitic plates like those
found in modern Echinoderms. Some believe that a carpoid may
have been the common ancestor between Echinoderms and Vertebrates.
It is important to note the carpoids differ from ALL other animals,
living and extinct, in that many are completely asymmetrical.
Here is an opportunity to have no less than three distinct enigmatic
taxa in a single assemblage, a specimen which will command pride
of place in any collection, private or institutional. When you
consider that some have offered a single shell plate of a machaeridian
for upwards of $200, this one is a bargain.
Reference: Nature, Vol 451, 10 Jan 2008, pp185 - 188.