A REVIEW OF THE PHYLOGENETIC POSITION OF THE LOMIDAE (CRUSTACEA: DECAPODA: ANOMALA)

Abstract

The position of the monotypic family Lomidae within the hermit crab superfamily Coenobitoidea is reviewed and rejected. Evidence is presented for an independent lineage of the Lomidae and the appropriateness of its elevation to the rank of superfamily Lomoidea within the infraorder Anomala. Lomis hirta (Lamarck) (Fig. 1) currently is classified in the family Lomisidae, superfamily Coenobitoidea, infraorder Anomura (Bowman and Abele, 1982), although Glaessner (1969) corrected the spelling of the family name from Bouvier's (1895) Lomisidae to Lomidae. From the International Code of Zoological Nomenclature (1964: 123), it is apparent that generic names ending in -is can form family names in several different ways, depending upon gender and declension. There appears to be no Latin root for Lomis and H. Milne Edwards (1837) gave no derivation of the name in his original description (J. Haig, personal communication). In the interest of simplicity in the formation of hierarchical names, I have elected to accept Glaessner's interpretation for the family Lomidae. Similarly, there is disagreement in the use of the infraordinal names Anomura H. Milne Edwards and Anomala De Haan. As pointed out by de Saint Laurent (1979) and Burkenroad (1981), when the Thalassinidea are excluded from consideration as anomurans, the name Anomala is more precise. It has been adopted in this context. L. hirta, an endemic Australian species, is the sole representative of the Lomidae. Because of its superficial resemblance to the porcelain crabs of the Galatheoidea, Lamarck (181) assigned it to the genus Porcellana. H. Milne Edwards (1837) recognized several significant differences between this species and the porcellanids and erected for it the genus Lomis, which he allied to the Lithodidae. H. Milne Edwards apparently was not thorough in his examination, and consequently described L. hirta as lacking terminal abdominal appendages (uropods). This error persisted until Pilgrim (1965) re-examined the species and found welldeveloped uropods in females and vestigial uropods in males. As pointed out by Pilgrim, errors such as that of H. Milne Edwards, or the failure to observe certain morphological characters of Lomis have led to a number of misinterpretations of its relationship to other anomalan taxa. Accepting H. Milne Edwards (1837) observations, a number of carcinologists continued to relate Lomis closely to the Lithodidae. Such a relationship was first denied by Bouvier (1894, 1895), who cited a number of characters that presumably showed Lomis to have been derived from a form intermediate between the hermit crab genera Mixtopagurus and Paguristes. Bouvier argued that L. hirta must have evolved from an asymmetrical ancestor and that the symmetry observed in this species had been arrived at secondarily. Boas (1926) questioned Bouvier's (1894) derivation of Lomis and expressed the belief that it probably had originated from the oldest symmetrical pagurid of the Pylochelidae (=Pomatochelidae, fide Miyake, 1978). Earlier Boas (1924) had speculated that perhaps Lomis might be best regarded as a modified galatheid, since the Galatheidae and Pylochelidae shared a number of characters in common.