Enoploclytia gigantea, 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 : 531

Enoploclytia gigantea n. sp.

( Fig. 8 E-H)

TYPE MATERIAL. — Holotype n°201 stored in the collections of the Bureau of Economic Geology , Texas (after Rathbun 1935).

TYPE LOCALITY. — Fort Worth , Texas ( United States of America).

TYPE AGE. — Albian, Early Cretaceous.

ETYMOLOGY. — The specific epithet refers to the Latin giganteus, - a, - um (= enormous) alluding to the exceptional size of the carapace.

DESCRIPTION

Carapace subrectangular in lateral view (holotype:CL= 175 mm, CH = 110 mm); rostrum not preserved; deep, sinuous cervical groove, joined to dorsal margin and to antennal groove; deep antennal groove, strongly curved and delimiting a slightly raised antennal lobe; long gastro-orbital groove, originating as a deep median inflexion of cervical groove, with two divergent branches delimiting two gastro-orbital lobes (flat upper lobe, slightly prominent lower lobe); deep, sinuous postcervical groove (strong sinuosity at carapace mid-height), joined to dorsal margin and to hepatic groove, with short ventral extension; short, shallow branchiocardiac groove, strongly inclined, joined to dorsal margin and not to postcervical groove; sinuous hepatic groove, joined to cervical groove; strongly inflated ω bulge; flat attachment site of adductor testis muscle (χ bulge); deep inferior groove; carapace covered with widely spaced tubercles; coarse tubercles in upper half of carapace and small tubercles in lower half of carapace; gastric region with a row of coarse tubercles parallel to intercalated plate; row of spines directed forward along dorsal margin.

DISCUSSION

The present carapace was initially identified as Palaeastacus walkeri byRathbun (1935), who was followed by Stenzel (1945; see discussion about Palaeastacus ). Our examination of the type material of P. walkeri leads us to a different conclusion. Indeed, this carapace shows groove pattern typical of Enoploclytia (long gastro-orbital groove, postcervical groove joined to hepatic groove, short branchiocardiac groove not joined to postcervical nor to hepatic grooves).

As for Enoploclytia augustobonae n. sp., Enoploclytia gigantea n. sp. (known by its carapace) cannot be compared to Enoploclytia wintoni (only known by P1 chelae). For a comparison, see discussion on E. augustobonae n. sp.

In conclusion, Enoploclytia gigantea n. sp. possesses the biggest carapace currently known among all erymid lobsters.

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.