Data from: The emergence of the lobsters: phylogenetic relationships, morphological evolution and divergence time comparisons of an ancient group (Decapoda: Achelata, Astacidea, Glypheidea, Polychelida)
Data files
Feb 11, 2014 version files 6.60 MB
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Appendix 1_Final_Table ALL EDITS.xls
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Appendix 10 Molecular_FINAL.pdf
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Appendix 11_PhyloBayes_species_FINAL.pdf
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Appendix 12_fossil justification.docx
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Appendix 13.pdf
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Appendix 2_ATOL Lobsters morpho list.docx
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Appendix 3_morphomatrix.pdf
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Appendix 4_morpho_FINAL.pdf
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Appendix 5mito_FINAL2.pdf
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Appendix 6_18S-FINAL3.pdf
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Appendix 7_28S_FINAL2.pdf
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Appendix_8_H3_FINAL2.pdf
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Appendix_9_IGTP_FINAL2.pdf
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README_for_Appendix 10 Molecular_FINAL.pdf
Abstract
Lobsters are a ubiquitous and economically important group of decapod crustaceans that includes the infraorders Polychelida, Glypheidea, Astacidea and Achelata. They include familiar forms such as the spiny, slipper, clawed lobsters and crayfish and unfamiliar forms such as the deep-sea and “living fossil” species. The high degree of morphological diversity among these infraorders has led to a dynamic classification and conflicting hypotheses of evolutionary relationships. In this study, we estimated phylogenetic relationships amongst the major groups of all lobster families and 94% of the genera using 6 genes (mitochondrial and nuclear) and 195 morphological characters across 173 species of lobsters for the most comprehensive sampling to date. Lobsters were recovered as a non-monophyletic assemblage in the combined (molecular + morphology) analysis. All families were monophyletic, with the exception of Cambaridae, and 7 of 79 genera were recovered as poly- or paraphyletic. A rich fossil history coupled with dense taxon coverage allowed us to estimate and compare divergence times and origins of major lineages using two drastically different approaches. Age priors were constructed and/or included based on fossil age information or fossil discovery, age, and extant species count data. Results from the two approaches were largely congruent across deep to shallow taxonomic divergences across major lineages. The origin of the first lobster-like decapod (Polychelida) was estimated in the Devonian (~409-372 million years ago (Ma)) with all infraorders present in the Carboniferous (~353-318 Ma). Fossil calibration subsampling studies examined the influence of sampling density (number of fossils) and placement (deep, middle, shallow) on divergence time estimates. Results from our study suggest including at least 1 fossil per 10 operational taxonomic units (OTUs) in divergence dating analyses.