Lithophylax A. Milne-Edwards & Brocchi, 1879

Guinot, Danièle & Breton, Gérard, 2006, Lithophylax trigeri A. Milne-Edwards & Brocchi, 1879 from the French Cretaceous (Cenomanian) and placement of the family Lithophylacidae Van Straelen, 1936 (Crustacea, Decapoda, Brachyura), Geodiversitas 28 (4), pp. 591-633 : 602

Genus Lithophylax A. Milne-Edwards & Brocchi, 1879

Lithophylax A. Milne-Edwards & Brocchi, 1879: 116 . — Van Straelen 1936: 43. — Stenzel 1953: 215. — Glaessner 1969: R514. — Bishop 1988: 247. — Vega & Feldmann 1991: 172, 173. — Vega et al. 1995: 345; 1997: 619. — Feldmann & Villamil 2002: 721. — Schweitzer et al. 2002a: 21; 2003a: 44. — Schweitzer & Feldmann 2005: 35, 42, tables 4, 7.

TYPE SPECIES. — Lithophylax trigeri A. Milne-Edwards & Brocchi, 1879 by monotypy.

DESCRIPTION

As for the species.

REMARKS

Guillier (1886: 238 pro 338, 244) quoted Lithophylax trigeri with the reference: “ Palaeoplax Trigeri, M. -Edw. Notes inédites (5)”, a footnote which referred to “Guillier. Notice géologique agricole etc. 1869, p. 32”. Palaeoplax Trigeri and Petrocarcinus Trigeri , used by A. Milne-Edwards in his personal handwritten notes (see Guillier 1886: 338 pro 238, 244) and on the labels (see Van Straelen 1936: 44), are nomina nuda.

Palaeoplax A. Milne-Edwards & Brocchi, 1879 (Milne-Edwards & Brocchi 1879: 114), with Goneplax incerta ( Desmarest, 1819) ( Desmarest 1819: 501 as Ocypode incerta ; see also Desmarest 1822: 104, pl. 8, fig. 9 as Gonoplax incerta ) as type species, shows superficial similarities with Lithophylax (large orbits, narrow front, marked areolation on whole carapace) but is clearly distinct. Palaeoplax incerta ( Desmarest, 1819) , based on a single worn specimen, was indicated, despite absence of any clear indication of provenance ( Desmarest 1819: 501: “I ignore from where this crab has been recorded, but its aspect somewhat evokes that of the Indian species”), to be a subfossil from the Indo-Pacific ( Glaessner 1969: R532). The assertion of Van Straelen (1936: 44) that Palaeoplax “was established to designate a subfossil goneplacid species named Goneplax incisa Desmarest ” was erroneous (a lapsus) since the type species of Palaeoplax is Goneplax incerta ( Desmarest, 1819) (1819, instead of 1822 as in the literature; the Latin name Ocypode incerta was published already in 1819 with the vernacular name “ Ocypode incertain” in the Nouveau Dictionnaire d’Histoire naturelle). Palaeoplax has been considered a good goneplacid genus ( Glaessner 1929: 300) or of uncertain systematic position ( Glaessner 1969: R532). The holotype of P. incerta (a female, about 29 mm width, MNHN B 41496; only a – supposedly subsequent – label “subfossile des Indes”), that we have examined, bears some resemblance to fossil thoracotreme crabs as the Macrophthalminae Dana, 1851, for example to the figure of Macrophthalmus vindobonensis Glaessner, 1924 (see Glaessner 1969: fig. 338.1), synonymised with M. aquensis A. Milne-Edwards & Brocchi, 1879 by Schweitzer et al. (2002a: 40). Even if the lateral borders of P. incerta are incomplete, the presence of the three deep transversal grooves on each side of the carapace are sufficiently characteristic to prevent its affiliation with the Lithophylacidae . We agree with Desmarest (1819) in thinking that it is related to Indo-Pacific crabs, and suggest that it is post-Cretaceous.