摘要

Craterostigmus tasmanianus Pocock, 1902, is the sole species in the centipede order Craterostigmomorpha and the focus of much phylogenetic research in Chilopoda. Originally named from Tasmania, Craterostigmus from New Zealand was first considered conspecific with Tasmanian samples based on external morphology, though recent anatomical studies have argued for a deep divergence between New Zealand and Tasmanian Craterostigmus, and a high-ranking taxonomic separation has been advocated. Unambiguous diagnostic nucleotide characters in nuclear ribosomal 18S and 28S rRNA genes as well as in the mitochondrial 16S rRNA, together with the significantly smaller size of New Zealand individuals, the arrangement of supernumerary Malpighian tubules, and patterns in leg spinosity, permit distinction of a New Zealand species, Craterostigmus crabilli, sp. nov. In addition, phylogenetic analysis of four markers (the aforementioned markers plus cytochrome c oxidase subunit I) suggests differentiation of C. tasmanianus from the New Zealand specimens. Combination of the nuclear ribosomal genes and mitochondrial 16S rRNA and COI sequences retrieves a geographic pattern within C. crabilli, sp. nov. in which geographic proximity is decoupled from closest affinities, although the 16S rRNA dataset alone shows more geographic structure. The genetic pattern observed, where among species diversity (for both mitochondrial markers) is equivalent to, or greater than, the within species diversity, is not consistent with a recent long-distance dispersal event, and a relictual Gondwanan distribution is the most plausible alternative.

  • 出版日期2008