Vetuprostomis Engel & Grimaldi, 2008

Li, Yan-Da, Hsiao, Yun, Huang, Di-Ying & Cai, Chen-Yang, 2022, New species of Vetuprostomis from mid-Cretaceous amber of northern Myanmar (Coleoptera: Tenebrionoidea: Prostomidae), Zootaxa 5125 (5), pp. 563-574 : 565-566

Genus Vetuprostomis Engel & Grimaldi, 2008

Remarks. Although Engel & Grimaldi (2008) mentioned that Prostomidae consist of two extant genera, Prostomis and Dryocora , it seems that they did not compare their fossil with members of Dryocora at all. Their differential diagnosis was proposed based on comparison with Prostomis solely. Engel & Grimaldi (2008) claimed that Vetuprostomis differs from modern prostomids in the shorter jugular processes, and the wider (about as wide as head) and the anteriorly constricted pronotum. However, extant Dryocora also has short jugular processes and anteriorly constricted pronotum. The pronotum can even be wider than head at least in some of Dryocora species. Indeed, Vetuprostomis is more similar to Dryocora than Prostomis . In addition to the characters mentioned above, Vetuprostomis and Dryocora share the shorter and more simple mandibles and the posterolaterally projected temples compared to the nominal genus.

Extant prostomids have mandibles with three apical teeth. In Engel & Grimaldi (2008), Vetuprostomis was described as having apically bidentate mandibles. This difference is merely due to a different terminology. The first apicomarginal tooth sensu Engel & Grimaldi (2008) is identical to the dorsal apical tooth in extant prostomids. In the present paper we follow the terminology used for the extant Prostomidae (e.g., Lawrence & Ślipiński 2013).

Key to species of Vetuprostomis

1. Lateral sides of clypeus anteriorly converging (fig. 2A in Engel & Grimaldi 2008). Penultimate maxillary palpomere wider than long, shorter than half length of apical one (?) (fig. 2C in Engel & Grimaldi 2008). Jugal processes symmetrical, without lateral teeth or knobs (fig. 2C in Engel & Grimaldi 2008). Median groove of pronotum well developed, (almost) as long as pronotal length (fig. 1 in Engel & Grimaldi 2008).......................................... V. consimilis Engel & Grimaldi

- Lateral sides of clypeus subparallel (or weakly diverging) in anterior portion ( Figs 4D , 7H ). Penultimate maxillary palpomere longer than wide, distinctly longer than half length of apical one ( Figs 4A,D , 7A,H ). Jugal processes asymmetrical; right process longer; inner sides with a tooth ( Figs 4A , 7A ). Median groove of pronotum absent or weakly developed, shorter than half length of pronotum ( Fig. 4E )............................................................................ 2

2. Jugal processes longer (e.g., right process: portion above tooth more than twice as long as portion below tooth) ( Fig. 4A ). Teeth on incisor edge of left mandible moderately separated ( Figs 3A , 4D ). Anterior angles of pronotum pointed ( Figs 2 , 4E )................................................................................ V. angularis Li & Cai sp. nov.

- Jugal processes shorter (e.g., right process: portion above tooth less than twice as long as portion below tooth) ( Fig. 7A ). Teeth on incisor edge of left mandible more narrowly separated and strongly jointed basally; interspace only very weakly notched ( Fig. 7H ). Anterior angles of pronotum not pointed ( Fig. 5 )................................. V. gaoi Li & Cai sp. nov.

Figures

FIGURE 2. General habitus of Vetuprostomis angularis Li & Cai sp. nov., holotype, NIGP177907, under incident light. A, Dorsal view. B, Ventral view. Scale bars: 1.5 mm.

FIGURE 3. Vetuprostomis angularis Li & Cai sp. nov., holotype, NIGP177907, under widefield fluorescence. A, Head and prothorax, dorsal view. B, Head and prothorax, ventral view. C, Elytral apex, dorsal view. D, Pterothorax, ventral view. E, Abdomen, ventral view. Abbreviations: an, antenna; el, elytron; jp, jugular process; md, mandible; msf, mesofemur; msts, mesotarsus; msv, mesoventrite; mtf, metafemur; mttb, metatibia; mtts, metatarsus; mtv, metaventrite; mxp, maxillary palp; pf, profemur; pn, pronotum; ps, prosternum; ptb, protibia; pts, protarsus. Scale bars: 500 μm.

FIGURE 4. Vetuprostomis angularis Li & Cai sp. nov., holotype, NIGP177907, under confocal microscopy. A, Mouthparts, ventral view. B, Prothorax, ventral view. C, Mesothorax, ventral view. D, Mouthparts, dorsal view. E, Prothorax, dorsal view. F, Fore leg. Abbreviations: an, antenna; cl, clypeus; ey, compound eye; jp, jugular process; lb, labrum; md, mandible; msv, mesoventrite; mxp, maxillary palp; pf, profemur; pn, pronotum; ps, prosternum; ptb, protibia; pts, protarsus. Scale bars: 300 μm.

FIGURE 5. General habitus of Vetuprostomis gaoi Li & Cai sp. nov., holotype, NIGP177908, under incident light. A, Dorsal view. B, Ventral view. Scale bars: 1.5 mm.

FIGURE 7. Vetuprostomis gaoi Li & Cai sp. nov., holotype, NIGP177908, under confocal microscopy. A, Mouthparts, ventral view. B, Temporal projection (arrowhead), ventral view. C, Prothorax, ventral view. D, Fore leg. E, Mesothorax, dorsal view. F, Hind leg. G, Abdomen, ventral view. E, Mouthparts, dorsal view. F, Elytral apex, dorsal view. Abbreviations: cl, clypeus; el, elytron; ey, compound eye; jp, jugular process; lb, labrum; lbp, labial palp; md, mandible; msv, mesoventrite; mt, mentum; mtf, metafemur; mttb, metatibia; mtts, metatarsus; mxp, maxillary palp; pc, procoxa; pf, profemur; ps, prosternum; ptb, protibia; ptc, protrochanter; pts, protarsus; v1–5, ventrites 1–5. Scale bars: 200 μm.