Phylogenetic systematics and biogeography of the sand crab families Albuneidae and Blepharipodidae (Crustacea: Anomura: Hippoidea)

Many unrelated crustaceans sharing a suite of convergent specialisations for a sand-burrowing existence have been placed in the anomuran family Albuneidae at one time or another. Although most of these non-albuneids have long since been reassigned to other families, recent molecular and morphological evidence has suggested a further split within the family between the Albuneidae (sensu stricto) and the Blepharipodidae. We used 173 morphological characters to test phylogenetic hypotheses about the monophyly of the Albuneidae and Blepharipodidae, as well as their constituent genera. We included 61 known species of albuneids and blepharipodids (including eight fossil species) and six outgroup species in five anomuran families. Analyses confirm that the Albuneidae and the Blepharipodidae are separate and monophyletic taxa that have convergently evolved similar adaptations to sand burrowing. Zygopa Holthuis, 1961 and Squillalbunea Boyko, 2002 are sister-taxa to the rest of the Albuneidae; all other Recent genera of albuneids are well supported and form two clades at the subfamily level. An Indo-Pacific origin for the Albuneidae is proposed and various scenarios regarding possible routes of dispersal are discussed.