Pseudagnostus prolongus

Order Agnostida / Suborder Agnostina / Superfamily Agnostoidea / Family Diplagnostidae

pseud-, Greek, false; Agnostus, a trilobite genus name.

prolongus, Latin, elongate, extended.

Agnostus prolongus; Cotalagnostus?prolongus; Pseudagnostus prolongus; Xestagnostus legirupa; X. rasilis Pseudagnostus(Pseudagnostina)vicaria

Border of cephalon and pygidium broad and flat, border furrow broad and shallow. Cephalon strongly effaced, dorsal furrow, glabellar furrows and basal furrows all weak, preglabellar median furrow weak or effaced; glabellar frontal lobe subrectangular, anterior margin inverted Broad V-shaped, F3 slightly curved backward, median node weak; Basal lobe elongate-triangular. Pygidial axis narrow, dorsal furrow developed only beside anterior axial ring, F1 and F2 weak or indistinct, median node located in M2; the posterior axial ring almost completely disappeared, with a terminal node at its end.

Palmer (1955) described two cephalic holotype specimens, numbered USNM 24637. Westrop et al. (2012) designated one of them as the lectotype and re-described it, but the margin was newly damaged.