DOI: 10.5061/dryad.sh3m0
title: Data from: Rigorous approaches to species delimitation have significant implications for African crocodilian systematics and conservation

description: Accurate species delimitation is a central assumption of biology that, in
 groups such as the Crocodylia, is often hindered by highly conserved
 morphology and frequent introgression. In Africa, crocodilian systematics
 has been hampered by complex regional biogeography and confounded
 taxonomic history. We used rigorous molecular and morphological species
 delimitation methods to test the hypothesis that the slender-snouted
 croco- dile (Mecistops cataphractus) is composed of multiple species
 corresponding to the Congolian and Guinean biogeographic zones. Speciation
 probability was assessed by using 11 mitochondrial and nuclear genes, and
 cranial mor- phology for over 100 specimens, representing the full
 geographical extent of the species distribution. Molecular Bayesian and
 phylogenetic species deli- mitation showed unanimous support for two
 Mecistops species isolated to the Upper Guinean and Congo (including Lower
 Guinean) biomes that were supported by 13 cranial characters capable of
 unambiguously diagnos- ing each species. Fossil-calibrated phylogenetic
 reconstruction estimated that the species split + 6.5 – 7.5 Ma, which is
 congruent with intraspecies diver- gence within the sympatric crocodile
 genus Osteolaemus and the formation of the Cameroon Volcanic Line. Our
 results underscore the necessity of com- prehensive phylogeographic
 analyses within currently recognized taxa to detect cryptic species within
 the Crocodylia. We recommend that the com- munity of crocodilian
 researchers reconsider the conceptualization of crocodilian species
 especially in the light of the conservation ramifications for this
 economically and ecologically important group.
description: Shirleyetal_Mecistopssystematics_CpDi13Mecistops and outgroup sequences for nuclear marker CpDi13. See text file "Shirleyetal_Mecistopssystematics_OTUexplanations.txt" for OTU codes. Refer to Methods text for other relevant details.Shirleyetal_Mecistopssystematics_CpP205Mecistops and outgroup sequences for nuclear marker CpP205. See text file "Shirleyetal_Mecistopssystematics_OTUexplanations.txt" for OTU codes. Refer to Methods text for other relevant details.Shirleyetal_Mecistopssystematics_CpP2902Mecistops and outgroup sequences for nuclear marker CpP2902. See text file "Shirleyetal_Mecistopssystematics_OTUexplanations.txt" for OTU codes. Refer to Methods text for other relevant details.Shirleyetal_Mecistopssystematics_CpP3303Mecistops and outgroup sequences for nuclear marker CpP3303. See text file "Shirleyetal_Mecistopssystematics_OTUexplanations.txt" for OTU codes. Refer to Methods text for other relevant details.Shirleyetal_Mecistopssystematics_CpP4004Mecistops and outgroup sequences for nuclear marker CpP4004. See text file "Shirleyetal_Mecistopssystematics_OTUexplanations.txt" for OTU codes. Refer to Methods text for other relevant details.Shirleyetal_Mecistopssystematics_LDHA_rag1Mecistops and outgroup sequences for nuclear markers LDHA and rag1. See text file "Shirleyetal_Mecistopssystematics_OTUexplanations.txt" for OTU codes. Refer to Methods text for other relevant details.Shirleyetal_Mecistopssystematics_mtDNAMecistops and Osteolaemus sequences for all 4 mitochondrial markers. See text file "Shirleyetal_Mecistopssystematics_OTUexplanations.txt" for OTU codes. Refer to Methods text for other relevant details.Shirleyetal_Mecistopssystematics_OTUexplanationsRelevant details concerning the OTU labels in all the sequence datasets.Shirleyetal_Mecistopssystematics_morphodataMorphological character codings. Each OTU is labeled with the numeric portion of the relevant museum accession number (see Table 3) and the supposed collection locality. Refer to Table 3 caption for further details.