Calappa sp.

Ossó, Àlex & Gagnaison, Cyril, 2019, An appraisal of the Middle-Late Miocene fossil decapod crustaceans of the ‘ Faluns’ (Anjou-Touraine, France), Geodiversitas 41 (9), pp. 367-383 : 372

Calappa sp.

( Fig. 3D, E )

MATERIAL EXAMINED AND MEASUREMENTS (in mm). — Two palms of a right (embedded in shell-grit matrix) and a left chelipeds, dactyli not preserved. Right chela, MS 2018-2-1: H = 28; left chela, MS 2018-2-2: H = 30.5; W = 33; T = 8.5.

LOCALITY AND HORIZON. — ‘La carrière-musée’ (Channay-sur- Lathan, Indre-et-Loire). Bioclastic calcarenite with Anadara turonica, Tortonian (Late Miocene).

DESCRIPTION

Palm subtrapezoidal, much higher distally. Upper margin strongly convex distally, cockscomb like; armed with six to eight teeth, being the distal ones acute and the medial ones blunt and larger. Lower margin straight, sharp edged. Outer surface of palm with coarse granules in the lower half, being smaller and tight in the upper half.

REMARKS

The two described chelae were recovered on a different stratigraphic level (Tortonian) than the Calappa praelata carapace described above (Languian-Serravallian), which does not allow us to assign with certainty those chelae to that species. They could be likely attributable to C. praelata , but the dense granulation of the outer surface of the palm differs from the less ornamented surface of the right chela figured by Müller (1984a: pl. 36, fig. 6) and attributed to C. praelata . The granules that stipple the outer surface of the palm, the shorter teeth of the upper margin of chelae, and the unrimmed lower margin precludes the attribution of the ‘Faluns’ chelae to C. granulata (see Müller 1984a: pl. 36, fig. 1). Consequently, we prefer to leave these chelae as Calappa sp.

Figures

FIG. 3. — A-C, Calappa praelata Lőrenthey in Lőrenthey & Beurlen, 1929, MS2006 FS 134a: A, dorsal view; B, frontal view; C, close-up of posterolateral margin; D, E, Calappa sp., MS2018-2-1: D, left chela, MS2018-2-2; E, right chela; F-J, Hebertides jurassica Guinot, De Angeli & Garassino, 2007; F-H, MS2018-1-1: F, right lateral view; G, frontal view; H, dorsal view; I, J, ULB-SO-1: I, fragment of right dorsal carapace; J, the same fragment showing bryozoans incrusted. Scale bars: A-H, 10 mm; I, J, 5 mm. Photographs by À. Ossó.