Name: Modocia
sp. (brevispina?); Agnostida (sp indet)
Class
Trilobita, Order
Ptychopariida, Family Marjumiidae & Order Agnostida
Geological
Time: Middle Cambrian
Size: Modocia:
17 mm long and 12 mm wide, 7 mm long and 5 mm wide Agnostids: 2-8 mm long
Location:
House Range, Marjum Formation, Millard County, Utah
 Description:
Coming from the Cambrian Marjum Formation deposits of Millard County,
Utah this is a fine association plaque of two trilobites of quite
disparate morphology.  The
larger trilobite is an example of the genus Modocia. A second smaller
example missing the librigenae is also present. There are also over
THIRT Y2- 8 mm examples of an agnostid trilobite . The members of
the Agnostida are mostly thought to have been planktonic in nature.
Most are blind, and have a pygidium equal in size to the cephalon
(ispopygous), making it hard to tell which end was which! This large
plaque makes an excellent display specimen of a death assemblage
of finely-preserved Middle Cambrian trilobites of Utah.
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