Stenodactylina insignis ( Oppel, 1862 )

Devillez, Julien & Charbonnier, Sylvain, 2021, Review of the Late Jurassic erymoid lobsters (Crustacea: Decapoda), Geodiversitas 43 (2), pp. 25-73 : 58

Stenodactylina insignis ( Oppel, 1862)

( Fig. 16 A-C)

Eryma insignis Oppel, 1862: 33 , pl. 10, fig. 1. — Van Straelen 1925: 264. — Förster 1966: 110.

Eryma anisodactylus Krause, 1891: 207 , pl. 13, fig. 4. — Van Straelen 1925: 270. — Förster 1966: 116.

Eryma ornata – Étallon 1861: 166, pl. 8, fig. 2.

Erymastacus insignis – Beurlen 1928: 175. — Glaessner 1929: 162. — Secrétan 1964: 74. — Hyžný et al. 2015: 376.

Erymastacus anisodactylus – Beurlen 1928: 175. — Glaessner 1929: 162.

Eryma anisodactylum – Schweitzer et al. 2010: 23.

Erymastacus anisodactylina – Hyžný et al. 2015: 376.

Stenodactylina insignis – Devillez et al. 2016: 524, table 1.

TYPE MATERIAL. — Cast of the holotype MNHN.F.A24613. TYPE LOCALITY. — Unknown locality, Haute-Saône departement, Bourgogne, France. TYPE AGE. — Oxfordian .

DESCRIPTION

Thoracic appendages

Chelate P1; elongated P1 propodus, trapezoidal, slightly globose medially; inflated dactylar bulge; elongated P1 fingers; dactylus progressively narrowing in its proximal half, inflected at mid-length, slender in its distal half, with a terminal hook; index with a wide basis, progressively narrowing in its proximal third, strongly inflected at its proximal third, slender and sinuous distally; occlusal margin with short conical teeth.

Ornamentation

Propodus and fingers covered by small tubercles.

DISCUSSION

The holotype of Eryma insignis is a P1 chela currently lost, but a cast is stored in the MNHN collections. In the literatur, some authors assigned this species to Eryma ( Van Straelen 1925; Förster 1966), while others assigned it to Erymastacus ( Beurlen 1928; Glaessner 1929; Secrétan 1964; Hyžný et al. 2015), which was established to group erymid chelae showing particularly elongated fingers. Later, Devillez et al. (2016) considering the elongated propodus with the long, slender, inflected and sinuous fingers, integrated E. insignis into Stenodactylina .

Like E. insignis , Eryma anisodactylus Krause, 1891 ( Fig. 16B ) has a complex history. Sometimes regarded as a species of Eryma ( Van Straelen 1925; Förster 1966; Schweitzer et al. 2010) or Erymastacus ( Beurlen 1928; Glaessner 1929; Secrétan 1964; Hyžný et al. 2015), Devillez et al. (2016) finally pointed out the similarities between these two species. Indeed, they are synonyms because of the shape of the P1 propodus and the length and shape of the fingers.

Stenodactylina insignis is only known by isolated P1 chelae, so comparisons to other species are limited. The wide basis of the index and its inflexion are diagnostic of the species. Moreover, the ornamentation lacking of coarse tubercles and spines on the propodus is distinct from S. armata ( Secrétan, 1964) , S. australis ( Secrétan, 1964) , S. falsani ( Dumortier, 1867) , S. lagardettei (Hyžný, Schlögl, Charbonnier, Schweigert, Rulleau & Gouttenoire, 2015) , S. liasina Beurlen, 1928 , S. rogerfurzei Schweigert, 2013 , S. spinosa ( Étallon, 1861) , S. strambergensis ( Bachmayer, 1959) , and S. triglypta ( Stenzel, 1945) .

Figures

FIG. 16. — Stenodactylina insignis (Oppel,1862), Stenodactylina shotoverigiganti n. sp. and Stenodactylina granulifera (Secrétan,1964):A, holotype of S. insignis (Oxfordian, Haute-Saône, France); B, holotype MFN 2236 P1383/2 MB.A.1536 of Eryma anisodactylus Krause,1891 (Kimmeridgian, Holzen,Germany); C, specimen IRSNB without number of S. insignis (Kimmeridgian, La Rochelle, France); D-G, holotype NHMUK 24559 of S. shotoverigiganti n. sp. (Oxfordian, Shotover, United Kingdom):right lateral view (D), left lateral view (E), schema (F), dorsal view (G); H-J, holotype MNHN.F.R03975 of S. granulifera (Kimmeridgian,Antsalova, Madagascar): lateral view (H), schema (J); C, D, holotype MNHN.F.R03974 of Eryma madagascariensis Secrétan, 1964 (Kimmeridgian, Antsalova, Madagascar). Abbreviations:a, branchiocardiac groove;b, antennal groove; b1, hepatic groove; c, postcervical groove; d, gastro-orbital groove; e1e, cervical groove; i, inferior groove;ip, intercalated plate; χ, attachment site of adductor testis muscle;ω, attachment site of mandibular muscle.Photographs:A, L. Cazes;B-E, G,J. Devillez; H, J, C. Lemzaouda. Line drawings: J. Devillez. Scale bars: 1 cm.