Weania semicircularis (Engel & Morris 1996)

Vanderlaan, Tegan A. & Ebach, Malte C., 2015, A review of the Carboniferous and Permian trilobites of Australia, Zootaxa 3926 (1), pp. 1-56 : 47

Weania semicircularis (Engel & Morris 1996)

Fig. 6.5

1922 Phillipsia convexicaudata Mitchell ; p. 535–536, pl. 54, figs. 8–10.

1996 Aprathia semicircularis Engel & Morris; p. 121–124, pl. 1, figs. 1–20, text-fig. 2.

Holotype. AMF27747/AMF28010 (external mould of dorsal shield/internal mould of counterpart).

Paratype material. AMF27449 (external dorsal shield), AMF96984a/b (external cranidium, internal/external librigena and internal/external pygidium), AMF96985a/b (2 internal/external cranidia), AMF96986 (external cranidium), AMF96987 (internal cranidium), AMF96988a/b (2 external pygidia and internal librigena), AMF96989a (2 external pygidium and glabella), AMF96990a/b (internal/external pygidium), AMF96991a/b (external/internal pygidium), AMF96992 (external pygidium), AMF96993 (external pygidium), AMF96994 (internal pygidium).

Locality. NU L 1039.

Emended diagnosis. Cephalon semicircular, lacking genal spines. Glabella touching anterior border, constricted at γ. Nine thoracic segments with wide axis. Pygidium with 9–10 axial rings, 8 pleural ribs; pleural furrows long, extend almost to margin; inter-pleural furrows broad and shallow, do not reach the pygidial margin; no border furrow.

Remarks. Weania semicircularis was assigned to the genus Aprathia based on the similarities to the pygidium of Aprathia applanata (Engel & Morris 1980), as well as the lack of a defined pygidial border or border furrow. However, similarities with the cephala of the type species of Weania , W. goldringi , support reassignment to this genus.. Weania semicircularis differs from the type species in having a more expanded glabella.