Evolution of Centipede

Centipedes have an ancestry dating back 430 million years to the late Silurian. Being one of the earliest terrestrial animals, centipedes were one of the first to fill a fundamental niche as ground level generalist predators in detrital food webs. Today centipedes are abundant and exist in many harsh habitats. Centipedes also have jointed legs and an exoskeleton.

Within the myriapods, centipedes are believed to be the first of the extant classes to branch from a common ancestor. There are five orders of centipede: Craterostigmomorpha, Geophilomorpha, Lithobiomorpha, Scolopendromorpha, and Scutigeromorpha.

Chilopoda is then split into two clades: the Notostigmomorpha including the Scutigeromorpha and the Pluerostigmomorpha including the other four orders. The main difference is that the Notostigmomorpha have their spiracles located mid-dorsally. It was previously believed that Chilopoda was split into Anamorpha including the Lithobiomorpha and the Scutigeromorpha, and Epimorpha including the Geophilomorpha and Scolopendromorpha based on developmental modes, with the relationship of Craterostigmomorpha being uncertain. A recent phylogenetic analysis using combined molecular and morphological characters supports the previous phylogeny. The Epimorpha group still exists as monophyletic within the Pleurostigmomorpha, but the Anamorpha group is paraphyletic.

Geophilomorph centipedes are used to argue for the developmental constraint of evolution; that the evolvability of a trait, the number of segments in the case of geophilomorph centipedes, was constrained by the mode of development. The geophilomorph centipedes have variable segment numbers within species, yet as with all centipedes they always have an odd number of pairs of legs. In this taxon, the number of segments range from 27 to 191 but no even number occurs.