Mecochirus Germar, 1827 Mecochirus longimanatus ( Schlotheim, 1820 )

Odin, Giliane P., Charbonnier, Sylvain, Devillez, Julien & Schweigert, Günter, 2019, On unreported historical specimens of marine arthropods from the Solnhofen and Nusplingen Lithographic Limestones (Late Jurassic, Germany) housed at the Muséum national d’Histoire naturelle, Paris, Geodiversitas 41 (17), pp. 643-662 : 654

Genus Mecochirus Germar, 1827

TYPE SPECIES. — Macrourites longimanatus Schlotheim, 1820 , by subsequent designation of Woods (1927).

Mecochirus longimanatus ( Schlotheim, 1820) ( Fig. 8 )

STUDIED MATERIAL. — Charbonnier & Garassino (2012) listed 27 specimens including two specimens described as Mecochiria foresti by Secrétan (1968). We add a new specimen from Solnhofen (MNHN.F.A70929).

COMMENTS

We localized the type material of Mecochiria foresti Secrétan, 1968. She listed five syntypes but figured only two (MNHN.F. A33537 : Fig. 8A, B; A 33539: Fig. 8F, G ), which are dorsoventrally flattened. According to Förster (1971), these specimens show diagnostic characters of Mecochirus longimanatus , and Mecochiria is a junior synonym of Mecochirus . This view was followed by Schweitzer et al. (2010: 20), who, however, maintained Mecochirus foresti as a separate species. Our examination of the two syntypes did not evidence any significant morphological differences to distinguish two species. Hence, we consider M. foresti as a junior synonym of M. longimanatus .

Specimen MNHN.F.A70929 ( Fig. 8 C-E) arrived in the MNHN collections in December 1930, through Mr Gravigny, Charles Brongniart’s son-in-law. The carapace exhibits the typical cervical groove and the orbital and gastro-orbital carinae. P1 is very elongate and P2 shows a strong and stout propodus as described by Garassino & Schweigert (2006).

Infraorder POLYCHELIDA Scholtz & Richter, 1995

Figures

FIG. 8. — Mecochirus longimanatus (Schlotheim, 1820): A, B, specimen MNHN.F.A33537; A, specimen in natural light; B, specimen in UV light; C, specimen MNHN.F.B13457; D-F, specimen MNHN.F.A70929; D, general view in UV light; E, view of the carapace in natural light; F, line drawing of the carapace; G, H, specimen MNHN.F.A33539; G, specimen in natural light; H, specimen in UV light. Abbreviations: ac, antennal carina; e1e, cervical groove; gc, gastro-orbital carina; oc, orbital carina. Scale bars: 1 cm. Photographs: L. Cazes. Line drawing: G.P. Odin.