Cairns, S.D. (1984). A generic revision of the Stylasteridae (Coelenterata: Hydrozoa). Part 2: Phylogenetic analysis. Bull. mar. Sci. 35(1): 38-53.
A generic revision of the Stylasteridae (Coelenterata: Hydrozoa). Part 2: Phylogenetic analysis.
Bull. mar. Sci.
A phylogenetic analysis was performed on the 23 genera of stylasterid corals, Hydractinia, a genus of athecate hydroid, was chosen as the out-group based primarily on morphological homology and secondarily on ontogeny, fossil record and advocacy. The evolutionary polarities of the 19 characters used in the analysis were established by out-group comparison and transformation series of multistate characters were ordered by apparent structural complexity and the process of reciprocal illumination. Several equally parsimonious cladograms are discussed and the justifications for choosing 1 in preference to the others are given. The interrelationships of the genera are discussed: Lepidopora is considered to be the most plesiomorphic genus, Pseudocrypthelia the most apomorphic. The final cladogram is compared to the evolutionary tree proposed by Moseley (1881). Within the context of the final cladogram, the relative value of the characters and degree of homoplasy are discussed. The stylasterids are considered as a family of athecate hydroids and the subfamilial designations are recommended to be abolished.Descriptors: HYDRACTINIA; LEPIDOPORA; PSEUDOCRYPTHELIAfigs. 1-4, appendices 1-2. (vii.1984). Kristian Fauchald's Polychaeta DB