Abstract
Abstract
Background
Polyplacophora, or chitons, have long fascinated malacologists for their distinct and rather conserved morphology and lifestyle compared to other mollusk classes. However, key aspects of their phylogeny and evolution remain unclear due to the few morphological, molecular, or combined phylogenetic analyses, particularly those addressing the relationships among the major chiton lineages.
Results
Here, we present a mitogenomic phylogeny of chitons based on 13 newly sequenced mitochondrial genomes along with eight available ones and RNAseq-derived mitochondrial sequences from four additional species. Reconstructed phylogenies largely agreed with the latest advances in chiton systematics and integrative taxonomy but we identified some conflicts that call for taxonomic revisions. Despite an overall conserved gene order in chiton mitogenomes, we described three new rearrangements that might have taxonomic utility and reconstructed the most likely scenario of gene order change in this group. Our phylogeny was time-calibrated using various fossils and relaxed molecular clocks, and the robustness of these analyses was assessed with several sensitivity analyses. The inferred ages largely agreed with previous molecular clock estimates and the fossil record, but we also noted that the ambiguities inherent to the chiton fossil record might confound molecular clock analyses.
Conclusions
In light of the reconstructed time-calibrated framework, we discuss the evolution of key morphological features and call for a continued effort towards clarifying the phylogeny and evolution of chitons.
Funder
Ministerio de Economía y Competitividad
National Science Foundation
Ministerio de Ciencia e Innovacion
Publisher
Springer Science and Business Media LLC
Subject
Ecology, Evolution, Behavior and Systematics
Reference108 articles.
1. Eernisse DJ, Reynolds PD. Polyplacophora. In: Harrison FW, Kohn AJ, editors. Microscopic Anatomy of Invertebrates, Volume 5. Mollusca 1. New York: Wiley-Liss; 1994. p. 56–110.
2. Schwabe E. A catalogue of recent and fossil chitons (Mollusca: Polyplacophora) addenda. Novapex. 2005;6:89–105.
3. Puchalski SS, Eernisse DJ, Johnson CC. The effect of sampling bias on the fossil record of chitons (Mollusca, Polyplacophora). Am Malacol Bull. 2008;25:87–95.
4. Kocot KM, Cannon JT, Todt C, Citarella MR, Kohn AB, Meyer A, et al. Phylogenomics reveals deep molluscan relationships. Nature. 2011;477:452–6.
5. Smith S, Wilson N, Goetz F, Feehery C, Andrade S, Rouse G, et al. Resolving the evolutionary relationships of molluscs with phylogenomic tools. Nature. 2011;480:364–7.
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