title: Integration of Morphological Data into Molecular Phylogenetic Analysis: Toward the Identikit of the Stylasterid Ancestor.
abstract: Stylasteridae is a hydroid family including 29 worldwide-distributed genera, all provided with a calcareous skeleton. They are abundant in shallow and deep waters and represent an important component of marine communities. In the present paper, we studied the evolution of ten morphological characters, currently used in stylasterid taxonomy, using a phylogenetic approach. Our results indicate that stylasterid morphology is highly plastic and that many events of independent evolution and reversion have occurred. Our analysis also allows sketching a possible identikit of the stylasterid ancestor. It had calcareous skeleton, reticulate-granular coenosteal texture, polyps randomly arranged, gastrostyle, and dactylopore spines, while lacking a gastropore lip and dactylostyles. If the ancestor had single or double/multiple chambered gastropore tube is uncertain. These data suggest that the ancestor was similar to the extant genera Cyclohelia and Stellapora. Our investigation is the first attempt to integrate molecular and morphological information to clarify the stylasterid evolutionary scenario and represents the first step to infer the stylasterid ancestor morphology.
authors.affiliation: Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Puce
authors.affiliation: Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, Ancona, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Pica
authors.affiliation: Dipartimento di Scienze della Terra, dell'Ambiente e della Vita, Università di Genova, Genova, Italy.|Museo Nazionale dell'Antartide (MNA, Sede di Genova), Genova, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Schiaparelli
authors.affiliation: Dipartimento di Biomedicina Comparata e Alimentazione, Agripolis, Università di Padova, Legnaro, Padova, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Negrisolo
mesh_terms: D000818:Animals; D005075:Biological Evolution; D004247:DNA / Q000235:genetics; D037402:Hydrozoa / Q000033:anatomy & histology / Q000235:genetics*; D010802:Phylogeny
chemical_list: D004247:DNA