Struveria sp. 1

Sandford, Andrew C. & Holloway, David J., 2006, Early Silurian phacopide trilobites from central Victoria, Australia, Memoirs of Museum Victoria 63 (2), pp. 215-255 : 246

Struveria sp. 1

Figures 12B–C

Material. NMV P139357 (partly disarticulated dorsal exoskeleton with displaced hypostome, thorax and pygidium) from PL1386, Geological Survey locality B3 (exact locality unknown), Moonee Ponds Creek, Broadmeadows. Precise stratigraphic horizon uncertain.

Remarks. The cephalon of the specimen has the glabella except for the anteriormost part obscured by the displaced hypostome and medial part of the doublure. Much of the left fixigena is preserved, including the large palpebral lobe and the posterior border, the latter curving backwards abaxially to the base of the genal spine. The pygidium is more completely preserved than the cephalon, is almost twice as wide as long (sag.), with six or seven axial rings and pleural furrows, and the axis comprising a little more than 25% maximum pygidial width anteriorly. The specimen can be assigned to Struveria with confidence on the basis of the pygidial morphology.

The hypostome of Struveria has not previously been illustrated. That of the present specimen is similar to hypostomes of other dalmanitids (e.g. see Ramsköld, 1985, pl. 10, fig. 12).

Figures

Figure 12. A, Phacopidella? sp., NMV P1218, dorsal exoskeleton, × 2.7, from PL1393, Keilor. B–C, Struveria sp. 1, NMV P139357, partly disarticulated exoskeleton with hypostome and cephalic doublure exposed, from PL1386, Broadmeadows; B, × 3.4; C, × 4. D–F, Phacopidae gen. indet. 2, NMV P312076, cephalon, × 8, from PL1369, Springfield. (A, E–F are internal moulds).