In a recent paper published in Molecular Phylogenetcs and Evolution, Giribet and Ribera (1998) placed rthropods within the Animal kingdom by analyzing he 18S rDNA locus of 133 metazoan taxa. The goal of hat paper was twofold: (1) to investigate the position of he Arthropoda within the protostome animals and (2) o determine arthropod sister-group relationships. Seuence data were analyzed by mean...

For the kingdom Animalia, 1,552,319 species have been described in 40 phyla in a new evolutionary classification. Among these, the phylum Arthropoda alone represents 1,242,040 species, or about 80% of the total. The most successful group, the Insecta (1,020,007 species), accounts for about 66% of all animals. The most successful insect order, Coleoptera (387,100 species), represents about 38% o...

Molecular investigations of deep-level relationships within and among the animal phyla have been hampered by a lack of slowly evolving genes that are amenable to study by molecular systematists. To provide new data for use in deep-level metazoan phylogenetic studies, primers were developed to amplify a 1.3-kb region of the alpha subunit of the nuclear-encoded sodium-potassium ATPase gene from 3...