Skip to Main Content
Book Chapter

Relationships between the extant Anomalodesmata: a cladistic test

By
Elizabeth M. Harper
Elizabeth M. Harper
1
Department of Earth Sciences, Downing Street, Cambridge CB2 3EQ, UK (e-mail: emh21@cus.cam.ac.uk)
2
Department of Geology and Zoology, National Museums of Scotland, Edinburgh EH1 1JE, UK
Search for other works by this author on:
Elizabeth A. Hide
Elizabeth A. Hide
Present address: Department of Earth Sciences, Downing Street, Cambridge CB2 3EQ, UK
Search for other works by this author on:
Brian Morton
Brian Morton
3
The Swire Institute of Marine Science and Department of Ecology and Biodiversity, The University of Hong Kong, Hong Kong
Search for other works by this author on:
Published:
January 01, 2000

Abstract

Although ancient anomalodesmatans were apparently abundant shallow and deep burrowers, in Recent seas the subclass comprises some of the most specialized and rarest of all bivalves. The morphological adaptations associated with diverse life habits has persistently frustrated attempts to achieve a widely accepted scheme for the relationships between extant families.

A cladistic analysis, using 43 informative anatomical and shell characters for each of the extant anomalodesmatan families has produced a single, reasonably robust tree which is in broad, albeit imperfect, agreement with the known fossil record of the subclass. This total evidence tree places the Pandoridae, Lyonsiidae, Cleidothaeridae and Myochamidae, and also the Thraciidae, Periplomatidae and Laternulidae in monophyletic groups. Carnivory appears diphyletic, with the Parilimyidae separated from the ‘septibranch’ families (Cuspidariidae, Verticordiidae, Lyonsiellidae and Poromyidae) which form a monophyletic group. The enigmatic tube-dwelling Clavagellidae appear as a sister group to the ‘septibranchs’.

Re-analysis of the data matrix using only those 18 characters which could be scored from shell characters alone, produced a tree which contradicted the total evidence tree rather than producing a poorly resolved version. The degree of convergence shown by shell characters make it, at least at present, difficult to include the extinct anomalodesmatan families in a cladistic analysis.

You do not currently have access to this article.

Figures & Tables

Contents

Geological Society, London, Special Publications

The Evolutionary Biology of the Bivalvia

E. M. Harper
E. M. Harper
Cambridge University, UK
Search for other works by this author on:
J. D. Taylor
J. D. Taylor
The Natural History Museum, UK
Search for other works by this author on:
J. A. Crame
J. A. Crame
British Antarctic Survey, UK
Search for other works by this author on:
Geological Society of London
Volume
177
ISBN electronic:
9781862394254
Publication date:
January 01, 2000

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal