Phylogenetic analysis among the families of the Cyclophyllidea (Eucestoda) based on comparative morphology, with new hypotheses for co-evolution in vertebrates

摘要

Phylogenetic analysis of families of Cyclophyllidea based on comparative morphology supported monophyly of the order. Four equal length trees (CI = 0.71) resulted from analysis of 42 binary and multistate characters. The results indicated a basal position for the arostellate groups, with Mesocestoididae + Nematotaeniidae representing the basal subclade; polyphyly for the Anoplocephalidae with sister-group associations postulated respectively for Anoplocephalinae + Thysanosomatinae and Linstowiinae+ Inermicapsiferinae; recognition within the rostellate cyclophyllideans of taeniid, dilepidid and davaineid subclades and the Dipylidiidae; designation of Metadilepididae + Paruterinidae as sister taxa; monophyly for the Davaineidae with all inclusive subfamilies; and a close relationship for the Hymenolepididae and acoleate cyclophyllideans. Monophyly for such classically defined groups as the Mesocestoididae, Taeniidae and Davaineidae is corroborated. Polyphyly of the Dilepididae sensu lato, with independence of the Dipylidiidae, Dilepididae sensu Bona (1994), the Metadilepididae + Paruterinidae, and the Gryporhynchidae is confirmed. These constitute testable hypotheses for monophyly and relationships among cyclophyllidean families. Initial diversification of Cyclophyllidea occurred in mammalian hosts and 3 independent events of colonization of avian taxa are postulated. Origins of the Cyclophyllidea extend into the Mesozoic or earlier, with extant taxa representing lineages that were persistent across the extinction event that defines the Cretaceous-Tertiary boundary.