Laetopsia mongolica ( Ponomarenko, 1987 ) 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 : 96-98

† Laetopsia mongolica ( Ponomarenko, 1987) comb. nov.

( Figs. 10–11 , 58–60 )

Hydrophilopsia mongolica Ponomarenko, 1987: 97 .

Type locality and age. Mongolia, Shin Khuduk, Middle-Gobi province . Lower Cretaceous, Hautervian to Barremian, ca. 136–125 mya ( DURANTE & BAKULBEKOV 2009; Vasilenko, pers. comm. to A. Prokin, 2011) .

Material examined (17 spec.). HOLOTYPE: PIN 3664/1567 (piece only). PARATYPES: PIN 3664/1480 (piece only); PIN 3664/1493 (piece only); 3664/1569 (piece only); PIN 3664/1573 (piece only); PIN 3664/1574 (piece only); PIN 3664/1583 (piece only); PIN 3664/1587 (piece only); PIN 3664/1642 (piece only); PIN 3664/1650 (piece only); PIN

3664/1655 (piece only); PIN 3664/1661 (piece only); PIN 3664/1663 (piece only); PIN 3664/1672 (piece only); PIN 3664/1683 (piece only); PIN 3664/1771 (piece only); PIN 3664/1772 (piece only); PIN 3664/1784 (piece only).

Redescription. Body elongate oval, 8.0– 9.5 mm long (holotype 9.5 mm). Head with protruding eyes, frontoclypeal suture Y-shaped, with grooved median portion; anterior margin of clypeus straight; labrum transverse, tightly attached to anterior margin of clypeus. Gula slightly constricted but gular sutures still widely separate. Pronotum with median longitudinal groove, pronotal flanks narrow, widest anteriorly, narrowing posteriad; prosternum long anterior to procoxae. Elytral striae 1–8 darkened; scutellary stria absent. Mesocoxae contiguous, metaventrite much longer than mesoventrite, metepimeron wide. Abdomen with 5 ventrites.

Note. The specimens examined show a wide variation in body proportions which are likely the result of deformations during the fossilization process. Besides these differences, we did not find any indication that more species should be present at the locality. Therefore, in agreement with the original description, we treat all specimens as a single species. Laetopsia mongolica clearly differs from both Laetopsia species from the Yixian formation which is considered as roughly of the same age as Shin Khuduk by some authors ( SWISHER et al. 1999) and was/is moreover rather close to it geographically – it has continually arcuate lateral margins of pronotum (in contrast to angulate margins in L. hydraenoides ) and rather narrow prosternum in front of procoxae (in contrast to long precoxal portion of prosternum in L. shatrovskiyi ).

Figures

Figs.9–13. Laetopsia gen. nov. 9 – L. hydraenoides (Prokin, Ren & Fikáček, 2010), holotype. 10–11 – L. mongolica (Ponomarenko, 1987) (10 – PIN 3664/1567, holotype; 11 – PIN 3664/1661). 12–13 – L. shatrovskiyi (Prokin, Ren & Fikáček, 2010) (12 – CNU 2010199; 13 – CNU 2010242, holotype). Scale bars: 2 mm (a: Figs. 9, 12–13; b: Figs. 10–11). Abbreviations: ant – antenna; sct – scutellum.

Figs. 53–62.Representatives of Laetopsia gen.nov.53–56 – L.baissensis (Ponomarenko, 1986) (53 – PIN 3064/7016; 54–55 – PIN 3064/6987, piece and counterpiece; 56 – detail of PIN 3064/6987). 57, 61 – L. hydraenoides (Prokin, Ren & Fikáček, 2010), CNU 2010021, holotype (57 – detail of head and pronotum; 61 – general view). 58–60 – L. mongolica (Ponomarenko, 1987) (58 – PIN 3664/1661, detail of head and pronotum; 59 – PIN 3664/1772; 60 – PIN 3664/1567, holotype). 62 – L. bontsaganica (Prokin, 2009), holotype. Scale bars: 1 mm.