Cladistic perspectives on early bivalve evolution

Abstract

Parsimony analysis suggests derivation of the Bivalvia from monoplacophorans rather than from rostroconchs, and additionally indicates that a phylogenetic classification of the Bivalvia can be achieved by erecting the superorder Nuculaniformii nov. and the order Nuculanoida nov. for the superfamily Nuculanoidea; relegating all other palaeotaxodonts to the superorder Nuculiformii; restricting the order Nuculoida to the families Nuculidae and Pristiglomidae; expanding the order Solemyoida to include ctenodontid genera as basal plesions; restricting the superorder Heteroconchia to palaeoheterodonts and heterodonts, exclusive of the Modiomorphidae; relegating the new family Evyanidae, the Colpomyidae, Matheriidae and Modiolodontidae to near-basal plesion status within the superorder Pteriomorphia; restricting the Mytiloida to the superfamily Mytiloidea, inclusive of modiolopsid genera as basal plesions; placing Ortonella as a basal plesion within the Cyrtodontoida; expanding the order Pectinoida to include the Myodakryotidae and the suborders Limina and Pectinina; and expanding the superfamily Arcoidea to include the frejid genera and Catamarcaia as basal plesions, and the family Glyptarcidae. Modiomorphid anomalodesmatans appear to be more closely related to the Pteriomorphia than to the Heteroconchia, and Evyana lies close to the common ancestry of modiomorphids and colpomyid pteriomorphians. Arcoids may have evolved from left-right symmetrical but otherwise rhombopteriid-like ancestors, rather than from actinodontoids or directly from cyrtodontids. The new family Eodonidae is proposed to distinguish the nacreous genus Eodon from the non-nacreous Astartidae within the superfamily Crassatelloidea.

Treatise Online no. 48: Part N, Revised, Volume 1, Chapter 31: Illustrated Glossary of the Bivalvia

“…cardinolateral tooth. A hinge tooth in which the proximal (beakward) portion has the appearance and position of a cardinal tooth, but the distal portion extends farther from the beak than a typical cardinal tooth (Carter, CaMpBell, & CaMpBell, 2000). Some cardinolateral teeth are derived from separate cardinal and lateral teeth that have become colaminar, and are therefore no (steNZel, 1971, fig.…”

“…pivotal tooth. (1) The largest and most central (if two or more of equal size) cardinal or subumbonal tooth on an adult hinge, regardless of its ontogenetic origin; a morphological character devoid of implied homology (NeWell & Boyd, 1975;Carter, CaMpBell, & CaMpBell, 2000); (2) in the Félix BerNard (1895, 1896a, 1896b, 1897) system of notation of heterodont dentition, the cardinal tooth derived ontogenetically by modification of the posterior end of the early juvenile innermost anterior dental lamella. In a lucinoid hinge, this is the left anterior cardinal (tooth 2).…”

“…pretaxodont dentition. A hinge dentition consisting of two to four stout, more or less orthomorphodont teeth that do not significantly increase in number with an increase in shell length beyond 1 mm (Carter, CaMpBell, & CaMpBell, 2000). The associated hinge plate does not extend far posterior to the beaks because that part of the shell is occupied by the ligament.…”

Supraspecific Taxa of the Bivalvia First Named, Described, and Published in China (1927–2007)

“…1,1-2) described and figured a new species that he named Taselasmodum decussatum. because this is a valid description and figure, Fang and cope (2004) (1983), we have a clearer understanding of the characters of the poorly known genus Nyassa Hall and Whitfield, 1869. carter, campbell, and campbell (2000, 2006 restored the family name Nyassidae Hall, 1885, which includes the type genus and the genus Tanaodon Kirk, 1927.…”

Treatise Online no. 43: Part N, Revised, Volume 1, Chapter 16: Origin and early evolution of the Bivalvia

“…The phylogenetic analysis of carTer, caMPbell, and caMPbell (2000) suggested that the Bivalvia is more closely related to Watsonella (Stenothecidae) and Pseudomyona runnegar, 1983 (Pseudomyonidae) than to Anabarella VosTokoVa, 1962, and the Rostroconchia. It seems that the Rostroconchia and Bivalvia share common laterally compressed pseudomyonid + stenothecid ancestry (Mackinnon, 1985;carTer, caMPbell, & caMPbell, 2000). The latter authors argued it is difficult to imagine how a hinged shell could have been derived from the specialized, rigidified dorsal area of pegma-bearing rostroconchs.…”