Helophorus (Mesosperchus) inceptivus, Fikáček & Prokin & Angus & Pono & Marenko & Yue & Ren & Prokop, 2012

Fikáček, Martin, Prokin, Alexander, Angus, Robert B., Pono, Alexander, Marenko, Yue, Yanli, Ren, Dong & Prokop, Jakub, 2012, Revision of Mesozoic fossils of the helophorid lineage of the superfamily Hydrophiloidea (Coleoptera: Polyphaga), Acta Entomologica Musei Nationalis Pragae 52 (1), pp. 89-127 : 104

† Helophorus (Mesosperchus) inceptivus sp. nov.

( Figs. 27 , 81–82 , 107, 111 )

Type locality and age. Mongolia, Gobi-Altai Province, SE Ajbogd-uul Range, S of Mount Shar-Teg, fossil site Shar-Teg, exposure 442/2; Shar-Teg sequence, Late Jurassic, Tithonian, ca. 150–145 mya ( GUBIN & SINITZA 1996; RASNITSYN & ZHERIKHIN 2002; YAN & ZHANG 2010).

Material examined (1 spec.). HOLOTYPE: PIN 4270/1008 (piece only).

Description. Adult: Body rather wide, body length 3.9 mm. Frons partly bearing weak granulation, gula wide, antenna with three-segmented antennal club. Pronotum transverse, with simply arcuate lateral margins and slightly angulate posterior margin; surface bearing five longitudinal grooves, all pronotal intervals with well-developed (through mostly only weakly preserved) granulation; anterolateral corners of pronotum probably not projecting. Prothoracic antennal grooves probably present. Elytron with 10 series of punctures, all series finely impressed; elytral intervals flat. Mesocoxal cavities very narrowly separated from each other, metaventrite slightly longer than mesoventrite. Mesotibia with several longitudinal series of spines, bearing few larger spines on distal margin; abdomen with five ventrites.

Figures

Figs. 27–28. Representatives of Helophorus, subgenus Mesosperchus Ponomarenko, 1977. 27 – H. (M.) inceptivus sp. nov. (PIN 4270/1008, holotype); 28 – H. (M.) yixianus sp.nov. (CNU 2010004, holotype). Scale bars: 1 mm. Abbreviations: ant – antenna.

Figs. 73–82. Representatives of Helophorus, subgenus Mesosperchus Ponomarenko, 1977. 73–79 – Helophorus tarsalis (Ponomarenko, 1977) (73 – PIN 3063/116, paratype; 74 – PIN 3063/2192, piece, general view; 75 – PIN 3015/1769; 76 – PIN 3063/2192, counterpiece, detail of male genitalia; 77– PIN 3063/2194. piece under alcohol; 78 – same specimen, counterpiece in dry condition; 79 – PIN 3015/367, holotype). 80 – Helophorus gracilis (Prokin, Ren & Fikáček, 2010), CNU 2010018, holotype. 81–82 – Helophorus inceptivus, PIN 4270/1008 (81 –detail of head and pronotum; 82 – general view). Scale bars: 1 mm (Figs. 73–80, 82); 0.5 mm (Fig. 81).

Figs. 104–112. Mesozoic representatives of the helophorid lineage, scanning electron micrographs. 104–106 – Laetopsia baissensis (Ponomarenko, 1986), PIN 3064/7018 (104 – general view; 105 – detail of head and pronotum; 106 – detail of meso- and metathorax). 107, 111 – Helophorus (Mesosperchus) inceptivus sp. nov. (107 – general view; 111 – detail of pronotum). 108–112 – Helophorus (Mesohelophorus) paleosibiricus nom. nov. (108 – PIN 3064/6981, general view; 109 – PIN 3063/863, holotype, 110 – PIN3064/6981, detail of prothorax, ventral view; 112 – same, dorsal view).