PEET - Bivalves Project: Veneroidea Phylogeny

Trainees: Isabella Kappner, Ph.D. Student, University of Illinois at Chicago and Field Museum of Natural History, 2000-2007; Timothy A. Rawlings, Postdoctoral Researcher, Florida International University and Field Museum of Natural History, 2004-2005.

The largest Recent family of Bivalvia, the marine Veneridae, comprises one of the least understood and most poorly defined molluscan taxa, despite including some of the most economically important and abundant bivalves. A review of previous phylogenetic analyses including the superfamily Veneroidea (Veneridae, Petricolidae, Glauconomidae, Turtoniidae, Neoleptonidae) and within Veneridae shows minimal taxon sampling leading to weak conclusions and few supported synapomorphies. New phylogenetic analyses on 114 taxa tested the monophyly of Veneroidea, Veneridae, and 17 nominal venerid subfamilies, using morphological (conchological, anatomical) data and molecular sequences from mitochondrial (16S, cytochrome oxidase I) and nuclear (28S, histone 3) genes. Morphological analyses using 45 taxa and 31 characters supported monophyly of Veneroidea and Veneridae but only when certain taxa were excluded, revealing analytical difficulties caused by characters associated with neotenous or miniaturized morphology. Molecular analyses resulted in substantially higher clade consistency. Monophyly of Veneridae was supported only when Petricolidae and Turtoniidae were recognized as members with derived or neotenous morphologies, respectively. Morphological character mapping on molecular trees retained a high level of homoplasy, but revealed synapomorphies for major branch points and supported six subfamily groups (Dosiniinae, Gemminae, Samarangiinae, Sunettinae, Tapetinae, combined Chioninae + Venerinae).

Publications: Mikkelsen, P. M., R. Bieler, I. Kappner, and T. A. Rawlings. 2006. Phylogeny of Veneroidea (Mollusca: Bivalvia) based on morphology and molecules. Zoological Journal of the Linnean Society, 148: 439-521.

Presentations: Mikkelsen, P. M., R. Bieler, I. Kappner, and T. A. Rawlings. 2004. Toward a phylogeny of Veneroidea. Symposium: Bivalves – a Look at the Branches (organized by R. Bieler & P. M. Mikkelsen), Unitas Malacologia, Perth, Western Australia, 15 July 2004, p. 100.

Mikkelsen, P. M., R. Bieler, I. Kappner, and T. A. Rawlings. 2006. Phylogeny of hard-shelled clams (Bivalvia: Veneroidea) based on morphology and molecules. International Congress on Bivalve Development, Evolution and Ecology, Fifth International Congress of the European Malacological Societies, Universitat Autònoma Barcelona, Spain, 24 July 2006, p. 59.

Minton, R. L., P. M. Mikkelsen, and R. Bieler. 2003. Clams and clades: systematics of Veneridae. American Malacological Society, University of Michigan, Ann Arbor, 27 June 2003, p. 43.