Morphological phylogenetic analysis of the Family Glyphocrangonidae Smith, 1884 (Decapoda: Caridea)

The family Glyphocrangonidae includes 100 species placed in a single genus, Glyphocrangon A. Milne-Edwards, 1881. The group is morphologically complex due its many forms of ornamentation making character survey a complex task. This family was divided into two species groups and two species complexes, but some species did not belong to either of these groups.

These divisions were made outside of a phylogenetic context and this is the first attempt to trace the phylogeny of Glyphocrangonidae. The material examined was derived from two institutions: Museu Nacional/UFRJ (Rio de Janeiro, Brazil) and National Museum of Natural History (Washington D.C., U.S.A.). The data matrix includes 55 terminal taxa and 130 morphological characters.

Phylogenetic analyses were conducted using TNT software with heuristic search, with character states polarized by outgroup comparison. The analysis generated twelve most parsimonious trees (L = 989 steps; CI = 0.18 and RI = 0.50). The G. caeca species group is a monophyletic group.

The species of the G. holthuisi and G. regalis complexes were largely nested together. The G. spinicauda species group, which is the most speciose and complex of the family, was not monophyletic, with species of the group interspersed throughout the tree. Some of the species previously not assigned to a group nested strongly with other groups and species complexes.

Herein, we also shed light in an interesting phylogenetic pattern in Glyphocrangonidae, namely, in the increase in the complexity of body ornamentation in more derived groups. In this way, the present work contributes to a better phylogenetic understanding of the family Glyphocrangonidae.