title: Micrurus distans M812
design: We used ddRAD-seq to obtain genome-wide SNPs of many individuals of Ethiopian Ptychadena. We digested genomic DNA for 7 hours at 37 C with the enzymes SbfI and MspI [30]. We then purified DNA fragments using Serapure beads [22], ligated adapters with attached barcodes [31] and pooled samples in groups of eight (number of unique barcodes; S3 Table). We size-selected each pooled library of barcoded samples between 400 and 550 bp using a Pippin Prep (Sage Science, Beverly, MA, USA), and then amplified the size-selected pooled libraries using PCR to attach unique Illumina indices [31] (Table S3). We determined fragment size and concentration for each library on a Bioanalyzer 7500 with a high sensitivity DNA chip (Agilent, Santa Clara, CA, USA), and checked library quantity with quantitative PCR. We then pooled all libraries and sequenced them with an Illumina HiSeq2500 (100 bp paired-end reads) at the Genome Core Facility of New York University Abu Dhabi, United Arab Emirates.