Trincleioid British Trilobite Salterolithus caractaci
Asaphida; Superfamily: Trinucleoidea;
Time: Upper Ordovician
Size: mm (25.4mm=1
inch): 15 mm on 100 by 80 matrix
Caradoc Series, Harnage (Shales) Formation, Welshpool, England
caractaci (Order: Asaphida; Superfamily: Trinucleoidea; Family:
Trinucleidae) is a classic British Ordivician trilobite from the
North of England in Wales. This trilobite takes its name from J.W.
Salter, who wrote the definitive monograph on British trilobites
in the 1860s.
Trincleioid trilobites like Salterolithus are highly specialized,
but fall within the Asaphida via their asaphoid protaspides and
the presence of the ventral median suture in at least the more primitive
representatives of the superfamily. The characteristic morpholgy
has a broad Cephalic fringe, sloping outward, bilaminar, with numerous
pits on external surfaces, extending posterolaterally somewhat behind
rest of cephalon.