Elrathina
(?)
Name: Elrathina
(?)
Trilobite
Order Ptychopariida, Superfamily Ptychoparioidea, Family Alokistocaridae
Locality: House Range, Millard Co., Utah
Size: 15 mm
Stratigraphy: Marjum Formation, Middle Cambrian
Courtesy: Collected & photographed by Richie
Kurkewicz
Remarks: This is an intriguing specimen found in a Delta, Utah Rock
Shop. The label says it is from the Marjum Formation, but the species
is found in the Wheeler Formationm as Elrathina wheeleri = Ptychoparella
wheeleri. So is this a Ptychoparella, a new species, or a mistaken
identification? According to James Cook: "I think it is a Ptychoparella.
Elrathina is now considered a junior synonym. However, the only
described Ptychoparella [=Elrathina] in
Utah is from the Wheeler Shale,and is associated with Elrathia kingii.
It has 19 segments, and is now called Ptychoparella wheeleri. So
if this is
a Ptychoparella it must be a different species, if it is from the
Marjum Fm., and it appears to have fewer segments. In
Ca and Nv, Eoptychoparia and Syspacephalus are also now synonyms
of
Ptychoparella. So there seem to be quite a few species of it in the
western US. It would not be very surprising to find another new
one
in Utah."
