Trilobites
Order Ptychopariida Suborder Ptychopariina, Superfamily
Ptychopariacea,
Family Alokistocaridae
Geologic Age: Middle Cambrian
Trilobite 8 mm long
Weeks Formation, House Range, Millard County, Utah
Comment: The name is derived from the single spine on the 7th axial
lobe.
