Eucnemidae

Oberprieler, Rolf G., Ashman, Lauren G., Frese, Michael & Ślipiński, Adam, 2016, The first elateroid beetles (Coleoptera: Polyphaga: Elateroidea) from the Upper Jurassic of Australia, Zootaxa 4147 (2), pp. 177-191 : 185-187

Eucnemidae ? Genus and species 2

( Figs. 15–16 )

Description. A smaller specimen comprising left elytron and impression of entire ventral side. Length 3.9 mm, width at base of pronotum ca. 1.3 mm. Head apparently small, not completely concealed beneath prothorax in dorsal view. Pronotum elongate trapezoidal, sides straight and diverging, posterolateral angles subacute but not strongly produced; hypomera distinct, elongate, with deep antennal grooves indicated (left side of part); procoxae small, subglobular, close together but separate. Scutellar shield apparently small, triangular. Mesocoxae broadly separate, with broad cavity and flanking tubercles (clicking apparatus) indicated. Elytra elongate, laterally straight, apically broadly rounded; with 9 discernible striae of irregular large punctures, striae 1–5 on disc, 6–9 on lateral declivity; interstriae not raised. Mesocoxae not clearly discernible but apparently large; metaventrite flat, without discrimen; metacoxae large, transverse. Abdominal ventrites flat, smooth, subequal in length; sutures straight, last suture as thin as others (suggesting fusion of last two ventrites).

Material examined (1 specimen). Part (AM F.137138) consisting of cuticular remains of left elytron and impression of head, prothorax and right side of abdomen; counterpart (AM F.137139) comprising cuticular remains of head, small fragments of prothorax and right side of abdomen and impression of prothorax outline and left elytron. Talbragar Fish Bed ( Upper Jurassic : Kimmeridgian-Tithonian, 151 ±4 Ma), Gulgong, N.S.W., Australia, December 2009, coll. R. G. Beattie. Deposited in the Australian Museum, Sydney.

Remarks. The specimen is too poorly preserved to assign it to a family with confidence, but its body shape, the posteriorly angulate prothorax without distinct carinae, the small head largely hidden by the prothorax, the antennal grooves along the prothoracic hypomera, the broadly separate mesocoxae with apparent clicking apparatus and the seemingly fused last two ventrites suggest that it may also represent a species of Eucnemidae .

Figures

FIGURES 13 – 16. Eucnemidae, clicking apparatus and Genus and species 1 & 2. 13, Nematodes sp., clicking apparatus showing anterior tubercles of mesoventral cavity (arrow); 14, Genus and species 1, part (AM F. 140888); 15, Genus and species 2, part (AM F. 137138); 16, Genus and species 2, counterpart (AM F. 137139). Scale bars 1 mm.