Linguaphillipsia elongata (Mitchell 1918)

Vanderlaan, Tegan A. & Ebach, Malte C., 2015, A review of the Carboniferous and Permian trilobites of Australia, Zootaxa 3926 (1), pp. 1-56 : 33-35

Linguaphillipsia elongata (Mitchell 1918)

Fig. 6.1

1892a Phillipsia dubia Etheridge Jr. ; p. 126–128, pl. 21, figs. 3–4.

1892a Phillipsia sp. indet.; Etheridge Jr., p. 129, pl. 21, figs. 6–7.

1918 Phillipsia elongata ; Mitchell, p. 456–458, pl. 47, figs. 3–5, pl. 48, fig. 14, pl. 50, figs. 4–7. 1918 Phillipsia stroudensis Mitchell ; p. 453–454, pl. 46, fig. 14, pl. 51, fig. 11. 1918 Phillipsia rouchelensis Mitchell ; p. 473, pl. 48, figs. 4–7.

1971 Phillipsia elongata ; Fletcher, p. 117.

1971 Phillipsia ? stroudensis ; Fletcher, p. 116.

1972 Linguaphillipsia elongata ; Hahn & Hahn, p. 371–372.

1972 Conophillipsia? rouchelensis ; Hahn & Hahn, p. 386–387.

1972 Conophillipsia? stroudensis ; Hahn & Hahn, p. 387.

1975 Linguaphillipsia elongata elongata ; Engel & Morris, p. 166–170, pl. 1, figs. 9–11, pl. 2, figs. 12–16, text-fig. 13.

Lectotype. NGSF1500a/b (external/internal moulds of dorsal shield).

Paralectotype material. AMF35697 (internal cranidium and partial thorax), AMF35846 (partial internal pygidium), NGSF 1498 (internal dorsal shield), NGSF 1506 (internal pygidium and glabella).

Locality. Type—Given only as Binge Berry, Rouchel Brook NSW in Engel & Morris (1975).

Emended diagnosis. Glabella constricted, weakly tapering anteriorly, ending prior to the anterior margin; anterior border narrow, rolled; fixigenae broad, β – β sub–equal to δ – δ; palpebral lobes broad, with a straight ε – ζ section; eyes large, mounted on eye platform delineated by an elevated crescentic ridge. Nine thoracic segments. Pygidium with 18 – 20 axial rings, 13 – 15 pleural ribs; border slightly convex, without distinct furrow, separated by changed of slope from pleura; dorsal surface granulose.

Remarks. Linguaphillipsia elongata (Mitchell 1918) was split into two subspecies by Engel & Morris (1975), Linguaphillipsia elongata elongata (Mitchell 1918) and Linguaphillipsia elongata rouchelensis (Mitchell 1918) . Specimens of L. elongata rouchelensis are only of pygidia. These pygidia differ from those of L. elongata elongata in that they have a flatter profile and the slope of the pleurae to the pygidial border is indistinct. The pygidia are distinctive enough to be from different species, with the subspecies elevated to species rank herein.

The above diagnosis is taken from Engel & Morris’s (1975) diagnosis for Linguaphillipsia elongata (Mitchell 1918) , but emended to remove the differences in pygidial border morphology that included L. rouchelensis as a subspecies. As with L. divergens , L. elongata has an intramarginal zone inside the cephalic border, making it distinct from the type species L. terapaiensis .