Escheria dimidiata Foerster , 1891

Martin, Fikacek, Hajek, Jiri & Schmied, Heiko, 2011, On the identity of the fossil aquatic beetles from the Tertiary localities in the southern part of the Upper Rhine Graben (Coleoptera, Hydrophilidae, Dytiscidae), ZooKeys 78, pp. 15-25 : 20

Escheria dimidiata Foerster, 1891 Fig. 8

Escheria dimidiata Förster 1891: 363, plate XI, Figs 10a,b (original description from Brunstatt); Handlirsch 1908: 767 (catalogue)

Hydrobius dimidiatus : Théobald 1937: 169 (transferred to Hydrobius ); Hansen 1999: 319 (catalogue).

Taxonomic note.

Based on the original drawing by Förster (1891), the morphology of Escheria dimidiata agrees with that of Hydrophilidae : Hydrophilinae in many aspects: (i) mesocoxal cavities transverse, narrowly isolated from each other, (ii) metanepisternum rather narrow, (iii) epipleuron narrow but reaching elytral apex, and (iv) elytron with 10 longitudinal punctural series. None of these characters or their combination is, however, unique for the Hydrophiloidea and may be found in other beetle families as well (see e.g. Lawrence et al. 1999). Moreover, the medium body size (EL: 9 mm according to Förster (1891)) would indicate that the fossil should belong to the subtribes Hydrobiusina or Hydrophilina , whose representatives are characterized by a relatively large and well developed triangular mesoscutellar shield; in contrast, the scutellar shield is very small or reduced in Escheria dimidiata . Moreover, the re-examination of the fossil is impossible as the holotype was lost or destroyed. For all these reasons, Escheria dimidiata is removed from the fossil record of the Hydrophiloidea and is placed in Polyphaga incertae sedis.