Genus and Species Basseiarges mellishae
sp to Basseiarges mellishae gen nov sp nov
recent reference below: newly erected genus is Basseiarges and new
species is mellishae after Dr Martin Basse a researcher
of Devonian trilobites
Order Lichida, Family Lichidae, Subfamily Trochurinae
Time: Middle Devonian
mm = 1 inch): Trilobite is 23 mm long by 18 mm wide (counting spines)
on a 110 mm by 75 mm matrix
This unusual trilobite comes from a new location known as Jorf
in Morocco, close to the site from which the polished goniatie
ammonites originate. The preservation of the exoskeleton is reminiscent
of them in terms of texture, unlike many trilobites from Morocco.
The first examples I have come across were at the 2012 Tucson
show, and were exhibited by the premier US importer of Moroccan
specimens. I was unable to secure either, but did not give up
the search. Here is a fine specimen of the taxon which is thought
to be of the genus Akantharges. Note the pleasant strawberries
and cream color of the matrix which has infused the trilobite
with some of this color, making for a striking specimen. The
seam appears to be a natural infilling by crystal much like that
in the fossil reptile Keichosaurus from the Triassic of China.
The rugose trailing edge to cephalon and pygidium is most unusual.
Interestingly, every specimen I have seen seems to have some
slight displacement either laterally or vertically to the pygidium.
Perhaps this was a naturally weak feature. The flattened round
shape and spines along the edge of the pleural and pygidiial
lobes indicate to me a dweller of the seafloor. The body configuration
would have served the same function as snowshoes.
Reference: Batalleria, 18, March 2013, pp 15-24
pictures to enlarge
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