title: The evolution of centipede venom claws - open questions and possible answers.
abstract: The maxilliped venom claw is an intriguing structure in centipedes. We address open questions concerning this structure. The maxillipeds of fossil centipedes from the Carboniferous (about 300 million years old) have been described, but not been depicted previously. Re-investigation demonstrates that they resemble their modern counterparts. A Jurassic geophilomorph centipede (about 150 million years old) was originally described as possessing a rather leg-like maxilliped. Our re-investigation shows that the maxilliped is, in fact, highly specialized as in modern Geophilomorpha. A scenario for the evolution of the centipede maxilliped is presented. It supports one of the two supposed hypotheses of centipede phylogeny, the Pleurostigmophora hypothesis. Although this hypothesis appears now well established, many aspects of character evolution resulting from this phylogeny remain to be told in detail. One such aspect is the special joint of the maxilliped in some species of Cryptops. Cryptops is an in-group of Scolopendromorpha, but its maxilliped joint can resemble that of Lithobiomorpha or even possess a mixture of characters between the both. Detailed investigation of fossils, larger sample sizes of extant species, and developmental data will be necessary to allow further improvements of the reconstruction of the evolutionary history of centipedes.
authors.affiliation: Ludwig-Maximilians-University of Munich (LMU), Department of Biology II, Grosshaderner Str. 2, 82152 Planegg-Martinsried, Germany. Electronic address: joachim.haug@palaeo-evo-devo.info.
authors.forename: Joachim T
authors.initials: JT
authors.lastname: Haug
authors.affiliation: Ludwig-Maximilians-University of Munich (LMU), Department of Biology II, Grosshaderner Str. 2, 82152 Planegg-Martinsried, Germany.
authors.forename: Carolin
authors.initials: C
authors.lastname: Haug
authors.affiliation: Staatliches Museum für Naturkunde, Rosenstein 1, 70191 Stuttgart, Germany.
authors.forename: Günter
authors.initials: G
authors.lastname: Schweigert
authors.affiliation: Ernst-Moritz-Arndt-University of Greifswald, Zoological Institute and Museum, Cytology and Evolutionary Biology, Soldmannstrasse 23, 17487 Greifswald, Germany.
authors.forename: Andy
authors.initials: A
authors.lastname: Sombke
mesh_terms: D000818:Animals; D001180:Arthropod Venoms / Q000378:metabolism; D001181:Arthropods / Q000033:anatomy & histology* / Q000145:classification / Q000254:growth & development; D005075:Biological Evolution; D005580:Fossils; D006724:Hoof and Claw / Q000033:anatomy & histology* / Q000254:growth & development; D010802:Phylogeny
chemical_list: D001180:Arthropod Venoms
keywords: Chilopoda; Heteroterga; Maxilliped; Mazon Creek; Nusplingen Lithographic Limestone; Pleurostigmophora