PEET - Bivalves Project Pterioidea

Trainee: Ilya Tëmkin, Ph.D. Student, New York University and American Museum of Natural History, 2000-2006.

This dissertation project focused on the evolution of diversity in the bivalve superfamily Pterioidea, which includes the commercially important pearl oysters. The group is exceptionally morphologically diverse and its fossil record extends to the lower Middle Ordovician (470 million years ago). Throughout the Phanerozoic, the pterioideans occupied a remarkable variety of epifaunal and semi-infaunal habitats in tropical and subtropical continental shelf regions around the globe, and have always been integral components of coral reef and mangrove ecosystems.

An important part of this work was a phylogenetic analysis of molecular and morphological data, the results of which have definitively shown that the superfamily is monophyletic, but all but one extant family (save the monotypic Pulvinitidae) are polyphyletic. In addition, these results provided grounds for a functional interpretation of diversity in shell morphology and several aspects of soft anatomy in a historical prospective, revealing many cases of adaptation-driven phenotypic convergence. The phylogenetic results combined with evidence from the fossil record suggested a Triassic origin for the crown group Pterioidea, contrary to previous estimates.

The phylogenetic framework was used to revise higher-level systematics of the Pterioidea and the taxonomy of the two most species-rich and commercially important pterioid genera, Pteria and Pinctada, in light of the proposed phylogeny and extensive original morphological observations

Publications: Mikkelsen, P. M., I. Tëmkin, R. Bieler, and W. G. Lyons. 2004. Pinctada longisquamosa (Dunker, 1852) (Bivalvia: Pteriidae), an unrecognized pearl oyster in the western Atlantic. Malacologia, 46(2): 473-501, Proceedings of the International Marine Bivalve Workshop 2002.

Printrakoon, C., and I. Tëmkin. In press. Comparative ecology of two parapatric species of Isognomon (Bivalvia: Isognomonidae) of Kungkrabaen Bay, Thailand. In: Molluscs of Eastern Thailand: Proceedings of the International Marine Bivalve Workshop, Chanthaburi, Thailand, August-September 2005, with contributions on other molluscan groups, Rüdiger Bieler, Kashane Chalermwat, Paula M. Mikkelsen, Tan Koh Siang and Fred E. Wells, eds. Raffles Bulletin of Zoology.

Tëmkin, I.  2004. The first occurrence of pearls in the Atlantic winged oyster, Pteria colymbus (Röding, 1798), from the Florida Keys.  The Festivus, 36(10): 123-5.

Tëmkin, I. 2006. Anatomy, shell morphology, and microstructure of the living fossil Pulvinites exempla (Hedley, 1914) (Mollusca: Bivalvia: Pulvinitidae). Zoological Journal of the Linnean Society 148: 523-552.

Tëmkin, I. 2006. Morphological perspective on classification and evolution of Recent Pterioidea (Mollusca: Bivalvia). Zoological Journal of the Linnean Society 148: 253-312.

Presentations: Tëmkin, I. 2004. A new system for Pterioidea (Mollusca: Bivalvia). Symposium: Bivalves – a Look at the Branches (organized by R. Bieler & P. M. Mikkelsen), Unitas Malacologia, Perth, Western Australia, 15 July 2004, p. 145.

Tëmkin, I. 2005. Evolution of extant pterioidean bivalves (poster).World Summit on Evolution, Universidad San Francisco de Quinto, San Cristobal, Galapagos, Equador, 10 Jun 2005.

Tëmkin, I. 2006. Overcoming incongruence in the phylogeny of the Pterioidea. International Congress on Bivalvia, Universitat Autònoma de Barcelona, Bellaterra, Spain, 26 July 2006, p. 77-78.

Tëmkin, I., and P. M. Mikkelsen. 2003. The systematic status of the pearl oyster genera (Bivalvia: Pteriidae) as inferred from molecules and morphology. American Malacological Society, Special Session: PEET Meets Molluscan Taxonomy, University of Michigan, Ann Arbor, 28 June 2003, p. 58.