Description:
This is a stunning trilobite of genus Harpides that as of 2015
has not been formally described. However, it morphologically closely
resembles Harpides grimmi from the Millina formation in the Czech
Republic described by the famous paleontologist Joachim Barrande
in 1872 as Dictyocephalites grimmi.
Trilobite
Order Harpetida was not erected until 2002, when it was split
off from Order Ptychopariida
in which it was Suborder Harpina.
Harpetids are now mostly considered to be descended from the
Ptychopariids sometime
in the middle Cambrian. Harpetida is the least diverse
of all the trilobite orders by a wide margin, with but three
families represented. At the trilobite order level, the Harpetids
are generally also the rarest.
This
beautiful trilobite comes from the Lower Ordovician Fezouata
Formation of Morocco. Trilobites from this site only
emerged
after collecting commenced in 2010. The site is noted for
preservation in browns and shades of red due to diagenesis processes
during
sedimentary rock formation. Fossils from the site also vary
in
surface texture from fairly smooth to that of coarse sandpaper,
with the smoother fossils retaining more fine details. This
particular specimen exhibits superior preservation for the
Fezouata Formation,
as seen in the very fine details and articulation of both
the cephalon and pygidium. Note how wide is the cephalon brim
that
contained
the ports for its filter feeding lifestyle. Also not its
small pygidium.
Image credit: Fossilscapes |