Order Asaphida Suborder Asaphina, Superfamily Trinucleioidea,
Geologic Age: Lower Ordovician, Llandeilo Series
Trilobite is 15 mm long
Middleton Formation, Shropshire, United Kingdom
Remarks: Note the cephalic pits, called fenestrae, through which the
trilobite filtered food from the seafloor. The
passed through the pits in this ring.
Also see: European