Leptolythica, Vršanský, 2009

Vršanský, Peter, 2009, Albian cockroaches (Insecta, Blattida) from French amber of Archingeay, Geodiversitas 31 (1), pp. 73-98 : 83-85

Genus Leptolythica n. gen.

TYPE SPECIES. — Leptolythica vincenti n. sp., by monotypy.

ETYMOLOGY. — Combination of leptos (Greek for small) and lythos (Greek for stone), as a dedication to my colleague and friend Vincent Perrichot whose family name means “small stone” in the language of his native region the Brittany.

DIFFERENTIAL DIAGNOSIS. — The present taxon may be categorized as Liberiblattinidae based on almost ideally globular head, robust antenna and foreleg with two parallel rows of spines along the tibial posterior ridge.

Leptolythica n. gen. differs from all other genera in having extremely short maxillary palps (autapomorphy).

According to the rapid evolutionary tempo of early Liberiblattinidae , and despite the absence of diagnostic wings, the presence of one and the same genus in localities distant in time for at least 45 Ma (the latest published record of the Liberiblattinidae is Elisamoides Vršanský, 2004 from the Tithonian of Shar-Teg in Mongolia) is very unlikely. Thus we safely erect a new genus to include the present species.

DESCRIPTION

Head globular, with comparatively large, round eyes. Scape and pedicel very large as well as the fam.), holotype ARC-263.16: A, ventral view; B, dorsal view. Head third antennal segment; fourth segment very short. Antenna very short, with subequal, short and wide segments. Clypeus distinct. Mandibles slender, comparatively small. Labial palps distinct, coloured, with slender dense sensilla chaetica. Maxillary palp robust, thick but short, without coloration, with few sensilla chaetica. Apical segment the largest.

Forelegs cursorial, with two rows of slender spurs along longitudinal posterior femoral ridge and a strong terminal spine. Few short sensilla chaetica present on the anterior margin. Tibia short, with strong spurs. Tarsi very short and robust, with dense sensilla chaetica. Mid legs with comparatively short coxa, well-developed trochanter and robust femur and tibia. Femur with long sensilla chaetica on posterior, and short ones on anterior margins. Two longitudinal median ridges present.Tibia with strong spurs.

REMARKS

Robust foreleg tibia with massive tarsi and robust maxillary palps are unique autapomorphies, eventually linked with the life within forest litter and/ or, possibly, for digging.

Due to the absence of diagnostic wings, no relationships can be established. The general habitus indicates relationship with the Late Jurassic undescribed small Liberiblattinidae from the Karabastau Formation (unpublished).