Triadaspis bigeneris

Order Agnostida / Suborder Agnostina / Superfamily Agnostoidea / Family Clavagnostidae Triadaspis bigeneris

triad + aspis, tripartite shield, referring to the anterior, middle and posterior parts of the pygidial axis, each

bigeneris, Latin, of double origin, referring to its similarity to both Aspidagnostus and Oidalagnostus.

Cephalon nearly round to nearly square, surface smooth; with preglabellar median furrow; frontal lobe narrower than posterior lobe, posterior lobe with carinate median node; basal lobe moderate-sized; with lateral spines. Pygidium nearly pentagonal shaped; pygidial axis long, constricted medially, longitudinally tripartite; median node long and broad; a deep groove at the anterior third of the terminal lobe, terminal end pointed; border with a pair of lateral spines and a median spine.