Anatomy and phylogeny of Eurytellina (Tellinidae: Tellinoidea)

Author(s)

Rodrigo Cesar Marques

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB)
• Defense date: 2012-09-21

Examining board members

Luiz Ricardo Lopes de Simone; Ricardo Silva Absalao; José Eduardo Amoroso Rodriguez Marian; Flávio Dias Passos; Sergio Antonio Vanin

• Advisor: Luiz Ricardo Lopes de Simone

Abstract

Eurytellina (Fischer, 1887) (Tellinidae: Tellinoidea) is a taxon traditionally treated as a subgenus of Tellina Linnaeus, 1758. This taxons is characterized by usually reddish and elongated valves. The external ornamentation is composed of broad concentric lirations. This taxon has a wide geographicrange, found in the West Atlantic and Eastern Pacific, with two species previously assigned in South African Coast and one species in the Australian Coast. Just as other species of bivalves, the anatomy, as well as the phylogenetic relationship of Eurytellina is poorly understood. The purpose of this study is to present an overview of comparative anatomical and to establish the phylogenetic position of in Eurytellina among other related groups. For this purpose, was carried out a sampling of almost Eurytellina species. Also was added other Tellinidae species within the family, followed by other species from all families belonging to the Superfamily Tellinoidea - Semelidae, Psammobiidae, Solecurtidae and Donacidae. The complete analysis of comparative anatomy yielded 144 characters and 35 taxa analyzed. In this study 16 species is related to Eurytellina, 17 species belongs to the functional ingroup and 2 species (a venerid and a solenid representatives) are in the functional outgroup. Phylogenetic analysis was performed using the cladistic methodology. 8 topologies equally parsimonious were obtained, and subsequently reweighted in order to obtain a single topology. The reweighted has been interpreted as evolutionary model for Eurytellina, which allowed us to conclude that: a) The Eurytellina species in on the coast of America are a monophyletic group. The three species outside the Americas belong to another monophyletic group, oblinging us to revalidating an old taxon, named Tellinota Iredale, 1936; b) Family Tellinidae is monophyletic. Internally, the subfamily Tellininae appears as paraphyletic as the subfamily Macominae are monophyletic. c) The general topology of Tellinoidea corroborates some previously evolutionary proposed models with ecological and paleontological data d) Two new characters were found. The first is a process above the cruciform muscle. The second new anatomical feature is a oblique muscles crossing over the esophagus; d) Analyzing only the evolutionary model of Eurytellina can be inferred that some geological processes are responsible for the diversity of this taxon. Among these processes, the emergence of the Isthmus of Panama is best known, explaining the pattern of \"sister species\", reported in other taxa, which is also found in Eurytellina species (AU)

• FAPESP's process: 08/04833-9 - Anatomy and phylogeny of the genus Eurytellina (Tellinidae: Tellinoidea)
• Grantee: Rodrigo Cesar Marques
• Support Opportunities: Scholarships in Brazil - Doctorate