Stenodactylina pseudoventrosa Devillez & Charbonnier 2021, n. comb.

Stenodactylina pseudoventrosa (Beurlen, 1928) n. comb.

(Fig. 17A, B)

Eryma pseudoventrosa Beurlen, 1928: 158; 1933: 90. — Schweitzer et al. 2010: 24.

Eryma modestiformis (pars.) – Förster 1966: 118.

TYPE MATERIAL. — Holotype GPIT Ar/294/3. TYPE LOCALITY. — Hülben, Baden-Würrtemberg, Germany. TYPE AGE. — Kimmeridgian.

DESCRIPTION

Carapace

Sub-cylindrical carapace; spiny rostrum; fusiform intercalated plate; narrow post-orbital area; deep and wide cervical groove, strongly inclined dorsally, inflected at carapace mid-height, joined to dorsal margin and to antennal groove; deep and wide antennal groove; short, wide gastro-orbital groove, deep and oblique, originating as a median inflexion of cervical groove; postcervical and branchiocardiac grooves subparallel, slightly curved, very close; deep postcervical groove, not joined to dorsal margin and interrupted in hepatic region; deep branchiocardiac groove, strongly inclined, not joined to dorsal margin.

Carapace covered by small tubercles preceded by crescentshaped depressions; cephalic region with an oblique orbital row of tubercles.

DISCUSSION

Known by a single cast of carapace, this species was originally assigned to Eryma (Beurlen 1928), and then regarded as a synonym of Eryma modestiforme (see Förster 1966). Careful examination of the holotype clearly shows the absence of junction between postcervical and branchiocardiac grooves and the interruption of the postcervical in the hepatic region. This groove pattern is diagnostic of Stenodactylina. So, the new combination Stenodactylina pseudoventrosa, n. comb. is here proposed.

The strong proximity of the postcervical and branchiocardiac grooves allows the distinction of S. pseudoventrosa, n. comb. from S. burgundiaca and S. delphinensis. Moreover, the ventral extremity of the postcervical groove of S. pseudoventrosa, n. comb. is lower than in S. burgundiaca, S. guisei, S. shotoverigiganti n. sp., S. triglypta, and S. walkerae. Contrary to S. australis, S. burgundiaca, S. delphinensis, S. deslongchampsi, S. granulifera, S. guisei, and S. triglypta, an orbital row is present in S. pseudoventrosa. There are also depressions and no coarse elements in its ornamentation contrary to S. australis, S. deslongchampsi, S. lagardettei, S. shotoverigiganti n. sp., S. triglypta, and S. walkerae.