Enoploclytia augustobonae, Devillez & Charbonnier & Hyžný & Leroy, 2016

Devillez, Julien, Charbonnier, Sylvain, Hyžný, Matúš & Leroy, Lucien, 2016, Review of the Early Cretaceous erymid lobsters (Crustacea: Decapoda) from the Western Tethys, Geodiversitas 38 (4), pp. 515-541 : 530-531

Enoploclytia augustobonae n. sp.

( Fig. 8 A-D)

TYPE MATERIAL. — Holotype MNHN.F.B14557.

TYPE LOCALITY. — Amance , Aube department, Champagne-Ardenne region, East France.

TYPE AGE. — Barremian, Early Cretaceous.

ETYMOLOGY. — The specific epithet refers to Augustobona, the Latin name of Troyes, the regional capital near the type locality.

DESCRIPTION

Subcylindrical carapace (holotype:CL = 63 mm, CH = 33 mm); rostrum not preserved; intercalated plate not preserved but underlined by a slight deviation of dorsal margin in cephalic region; deep cervical groove, joined to dorsal margin and to antennal groove, strongly inclined above gastro-orbital groove, subvertical under gastro-orbital groove; deep, narrow antennal groove, strongly curved; wide, shallow gastro-orbital groove originating as large median inflexion of cervical groove, with two divergent branches, delimiting two gastro-orbital lobes (flat upper lobe, slightly prominent lower lobe); sinuous postcervical groove, dorsally deep and ventrally shallow, joined to dorsal margin and to hepatic groove, with ventral extension at carapace midheight; short, shallow branchiocardiac groove, joined to dorsal margin and not to postcervical groove; concavo-convex hepatic groove, joined to cervical groove; inflated ω bulge; slightly inflated χ bulge; shallow inferior groove; cephalic region without antennal row of tubercles; carapace covered with small, widely spaced tubercles; cardiac region with a dorsal row of coarse tubercles; gastric region with a row of coarse tubercles parallel to intercalated plate and an oblique row of coarse tubercles.

DISCUSSION

The new species is assigned to Enoploclytia based on its typical carapace groove pattern: wide gastro-orbital groove, postcervical groove joined to hepatic groove, short branchiocardiac groove not joined to postcervical nor to hepatic grooves. It is also the oldest occurrence of Enoploclytia .

Enoploclytia augustobonae n. sp. cannot be compared to Enoploclytia wintoni , which is only known by its P1 chelae.

Enoploclytia augustobonae n. sp. differs from Enoploclytia gigantea n. sp. by its carapace groove pattern with: 1) a nonsinuous cervical groove; 2) a less incurved antennal groove; 3) a shorter and shallower gastro-orbital groove; and 4) a longer ventral extension of postcervical groove. Furthermore the ornamentation of these two species is different: Enoploclytia augustobonae n. sp. exhibits fine tubercles on all the carapace surface and coarse tubercles along dorsal margin and in gastric region, while E. gigantea n. sp. has coarse tubercles in the upper half of carapace, fine tubercles in the lower half of carapace, and a row of strong spines along dorsal margin.

Our review leads us to consider the Hauterivian species E.glaessneri as a representative of Eryma and to exclude E. salviensis from the Erymidae .In conclusion Enoploclytia augustobonae n. sp. is currently the oldest occurrence of the genus.

Figures

FIG. 8. — New species of Early Cretaceous Enoploclytia M’Coy, 1849: A-D, holotype MNHN.F.B14557 of Enoploclytia augustobonae n. sp. from the Barremian of Amance, France: carapace in right lateral view (A), and line drawing (B), dorsal view (C) showing the deviation of median line in cephalic region (intercalated plate) and line drawing (D); E-H, holotype of Enoploclytia gigantea n. sp. from the Albian of Fort Worth, USA: original figures of carapace by Rathbun (1935: pl. 4; figs 1, 2), left lateral view (E), right lateral view (F), and line drawings (G, H). Abbreviations: a, branchiocardiac groove; b, antennal groove; b1, hepatic groove; c, postcervical groove; d, gastro-orbital groove; e1e, cervical groove; i, inferior groove; ω, attachment site of mandibular muscle. Photographs: L. Cazes (A, C). Line drawings: J. Devillez. Scale bars: A-D, 10 mm; E-H, 20 mm.