Palaeoheterodont diversity (Mollusca: Trigonioida + Unionoida): what we know and what we wish we knew about freshwater mussel evolution

By Daniel L. Graf, K. Cummings. 2006

181 citations recorded by the source corpus.

The Palaeoheterodonta is a diverse clade consisting of the freshwater bivalve order Unionoida and its marine sister group, Neotrigonia. Neotrigonia is the sole surviving genus of the Trigonioida, known from only six species in Australian waters. Unionoids (freshwater mussels), in contrast, are widespread on all continents except Antarctica and are represented by c. 900 species. Discussion is biased towards the freshwater mussel condition, but Neotrigonia is crucial as a ‘living fossil’ for establishing the plesiomorphic states of unionoid synapomorphies. Neotrigonia retains many of the characters of the ancestral heteroconch. Our object is to provide evidential support for the natural classification of the extant Palaeoheterodonta. A supermatrix of 50 taxa and 1183 characters was constructed from 62 previously published DNA sequences of mitochondrial cytochrome oxidase subunit I (COI) and 28S nuclear ribosomal DNA, 15 novel sequences, and 59 morphological characters. Published COI sequences for Coelatura aegyptiaca, Pseudomulleria dalyi, and Obliquaria reflexa were treated as potentially problematic because of their inconsistency under different methodological assumptions and conflict with other datasets. Each partition was analysed under the criterion of parsimony separately and in combined analyses; analyses were run both with and without the problematic sequences. From our ‘combined evidence’ topology (with problematic sequences excluded), the Unionoida is monophyletic on the basis of eight synapomorphies, including larval parasitism, brood protection, and restriction to freshwater. The order is composed of six families in two superfamilies, Unionoidea and Etherioidea: ((Unionidae + Margaritiferidae) + (Hyriidae + (Etheriidae + (Mycetopodidae + Iridinidae)))). The morphological synapomorphies of these taxa are discussed with an emphasis on both the diagnosing of taxa and highlighting areas of ambiguity and missing data. Three appendices provide descriptions of the morphological characters (Appendix 1), a diagnosis of apomorphies for all branches of the phylogeny (Appendix 2), and a family-level classification of the extant Palaeoheterodonta, including a complete synonymy (Appendix 3). © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society, 2006, 148, 343–394.

Subfields: Ecology, Epidemiology, Insect Science

View Paper: https://www.semanticscholar.org/paper/d0ab858b6250be2bb9a3142d143f723dafbdfc29

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Ecology

1. Daniel L. Graf
2. E. Glover
3. Kevin J. Roe
4. John D. Taylor
5. Prashant P. Sharma
6. A. Bogan
7. R. Bieler
8. G. Y. Kawauchi

In Epidemiology

1. A. Bogan
2. Kevin J. Roe
3. Daniel L. Graf

In Insect Science

1. Daniel L. Graf
2. Kevin J. Roe
3. A. Bogan
4. E. Glover
5. John D. Taylor
6. R. Bieler
7. P. Mikkelsen
8. E. Strong

Citations in the corpus

• Freshwater bivalve (Unioniformes) diversity, systematics, and evolution: status and future directions (2008, methodology): “This separation has been confirmed by recent phylogenetic work (Roe and Hoeh 2003, Graf and Cummings 2006, Walker et al. 2006a).”
• Palearctic freshwater mussel (Mollusca: Bivalvia: Unionoida) diversity and the Comparatory Method as a species concept (2007, background): “Of the six ecozones listed in the Introduction, only Australasia has fewer species (33) (Graf and Cummings, 2006, and unpublished data).”
• Investigating the Bivalve Tree of Life – an exemplar-based approach combining molecular and novel morphological characters (2014, methodology): “Archiheterodonta is high for the separation between Trigoniida and Unionida (PP = 1.00), but the unionoid superfamilies are not supported by the analyses.”
• Patterns of Freshwater Bivalve Global Diversity and the State of Phylogenetic Studies on the Unionoida, Sphaeriidae, and Cyrenidae * (2013, background): “The principle area of agreement among the analyses so far is that the Folmer et al. (1994) fragment of cytochrome oxidase subunit I (COI) is not equal to the task of resolving freshwater mussel families (Graf and Cummings 2006, Hoeh et al. 2009, Whelan et al. 2011).”