Galatheidae Samouelle, 1819

Ahyong, Shane T., Baba, Keiji, Macpherson, Enrique & Poore, Gary C. B., 2010, A new classification of the Galatheoidea (Crustacea: Decapoda: Anomura), Zootaxa 2676 (1), pp. 57-68 : 59

Galatheidae Samouelle, 1819

( Figs 1B–F , 2A–D )

Galatheadae Samouelle, 1819: 92.

Galatheidae . — Dana, 1853: 1431.

Galatheinae . — A. Milne-Edwards & Bouvier, 1894: 244.

Diagnosis. Rostrum well developed, broad, flattened, usually subtriangular; supraocular spines present or absent. Carapace (excluding rostrum) as long as or longer than wide; dorsally with transverse striae. Tailfan well developed, not folded against preceding somite, telson distinctly or indistinctly subdivided into multiple plates. Eyes with well-developed cornea. Antennal peduncle directed anteriorly or anterolaterally. Maxilliped 1 exopod flagellum well-developed. Maxilliped 3 pediform; ischium and merus elongate, not expanded mesially; epipod present. Chelipeds subcylindical to ovate in cross-section.

Type genus. Galathea Fabricius, 1793 .

Composition. Extant genera: Alainius Baba, 1991 ; Allogalathea Baba, 1969 ; Allomunida Baba, 1988 ; Coralliogalathea Baba & Javed, 1974 ; Fennerogalathea Baba, 1988 ; Galathea Fabricius, 1793 ; Janetogalathea Baba & Wicksten, 1997 ; Lauriea Baba, 1971 ; Macrothea Macpherson & Cleva, 2010 ; Nanogalathea Tirmizi & Javed, 1980 ; Phylladiorhynchus Baba, 1969 .

Fossil genera: Acanthogalathea Müller & Collins, 1991 [Upper Eocene]; Lessinigalathea De Angeli & Garassino, 2002 [Lower Eocene]; Luisogalathea Karasawa & Hayakawa, 2000 [Upper Cretaceous]; Mesogalathea Houša, 1963 [Upper Jurassic to Cretaceous]; Palaeomunida Lőrenthey, 1901 [Upper Jurassic to Oligocene]; Spathagalathea De Angeli & Garassino, 2002 [Upper Eocene]; Lophoraninella Glaessner, 1945 [Upper Cretaceous].

Remarks. The Galatheidae are distinguished from the Munidopsidae by the presence of a well-developed flagellum on maxilliped 1 (absent or reduced in munidopsids), and from the Munididae fam. nov. by the broad and flattened rostrum (versus a usually slender rostrum with supraocular spines). The Galatheidae are herein restricted to the 11 extant and seven fossil genera formerly placed in the Galatheinae , sharing a broad, triangular rostrum. We follow De Angeli & Garssino (2002) in treating Spathogalathea as a galatheid, although we suspect it may be better placed in the Porcellanidae on the basis of the raised orbital rims, a feature often present in porcellanids but not galatheids.

Galatheids are more closely related to the porcelain crabs, Porcellanidae , than to other clades of squat lobsters ( Ahyong et al. 2009). Both families share a broad, flattened rostrum (though considerably shortened in porcellanids). Additionally, both galatheids and porcellanids are typically small (carapace length usually <15 mm) and usually occupy shallow-water or shelf habitats on rocky substrates or coral reefs, in contrast to outer shelf and slope habitats of typical munidids and munidopsids.

Figures

FIGURE 1. A, Phylogenetic relationships of the families of the Galatheoidea based on Ahyong et al. (2009) and Schnabel et al. (in press). B–H, walking leg dactyli of selected Galatheoidea. Galatheidae: B, Allomunida magnicheles Baba, 1988; C, Galathea tropis Baba, 2005; D, Lauriea gardineri (Laurie, 1926); E, Phylladiorhynchus cf. pusillus (Henderson, 1885); F, Alainius crosnieri Baba, 1991. Munididae fam. nov.: G, Munida exilis Ahyong, 2007; H, Agononida eminens (Baba, 1988). Figure sources: B (Baba 1988); C (Baba 2005); D (Baba 1994); E, G (Ahyong 2007); F (Baba 1991); H (Baba et al. 2008).

FIGURE 2. Carapace and abdomen (A–N) and anterior carapace (O) of selected Galatheoidea. Galatheidae: A, Galathea tropis Baba, 2005; B, Lauriea siagiani Baba, 1994; C, Alainius crosneri Baba, 1991; D, Allomunida magnicheles Baba, 1988. Munididae fam. nov.: E, Munida exilis Ahyong, 2007; F, Agononida eminens (Baba, 1988); G, Bathymunida ocularis Baba & de Saint Laurent, 1996; H, B. frontis Baba & de Saint Laurent, 1996; Munidopsidae: I, Munidopsis pycnopoda Baba, 2005; J, M. norfanz Ahyong, 2007; K, M. bractea Ahyong 2007; L, M. laciniosa Baba, 2005; M, Leiogalathea laevirostris (Balss, 1913); N, Galacantha rostrata A. Milne-Edwards, 1880; O, Shinkaia crosnieri Baba & Williams, 1998. Figure sources: A, I, L (Baba 2005); B (Baba 1994); C (Baba 1991); D (Baba 1988); E, J, K, M (Ahyong 2007); F, O (Baba et al. 2009); G, H (Baba & de Saint Laurent 1996); N (Baba & Poore 2002).