Taxon set and taxonomic data
The class Chondrichthyes is composed of two subclasses, the Holocephali (chimaeras) and the Elasmobranchii (sharks and rays), and includes 14 orders, 60 families, 198 genera and 1192 species (Supplementary table 1). Systematic relationships within Chondrichthyes, as with other taxa, are in flux[1–4], so we used the most recent combination of taxonomy and phylogeny to identify our taxon set (Chondrichthyan Tree of Life; downloaded October 15, 2015). Due to the inherent prolonged time required for analyses of this nature, taxonomic revisions often occur prior to completion and publication[5–9]. To aid readers in navigating recent changes that we could not incorporate into the analysis, we provide annotations to our master taxonomy highlight recent taxonomic revisions (Supplementary Table 1, column G) and include recently described species that have not been assessed and could not be included in this study (Supplementary Table 6). The subclass Holocephali includes one superorder (Holocephalimorpha) containing one order of Chimaeriformes (chimaeras); three families, six genera, and 49 species. The subclass Elasmobranchii includes three superorders: Batoidea, Galeomorphii, and Squalomorphii[10]. The superorder Batoidea includes four orders Myliobatiformes (stingrays), Rajiformes (skates), Rhinopristiformes (guitarfishes, wedgefishes, and sawfishes), and Torpediniformes (electric and thornback rays); 23 families, 86 genera, and 639 species. The sharks comprise two superorders: Galeomorphii and Squalomorphii. The superorder Galeomorphii includes four orders: Carcharhiniformes (ground sharks), Heterodontiformes (bullhead sharks), Lamniformes (mackerel sharks), and Orectolobiformes (carpet sharks); 23 families, 75 genera and 347 species. The superorder Squalomorphii includes five orders Hexanchiformes (cow sharks), Pristiophoriformes (saw sharks), Echinorhiniformes (bramble sharks), Squaliformes (dogfish sharks), and Squatiniformes (angel sharks); 11 families, 31 genera, and 157 species. The taxonomic hierarchy described above comprises the taxonomic data that we used to place and constrain those taxa without DNA sequence data.
For a complete species list and summary of revisions see Supplementary Table 1
Annotated checklist of the living sharks, batoids and chimaeras (Chondrichthyes) of the world, with a focus on biogeographical diversity. S. Weigman. Journal of Fish Biology, 88, 837-1037 Chondrichthyan Tree of Life Project IUCN Redlist