file descriptions: bedgraphs.tar.gz: ATAC-seq data in bedgraph format for each sea urchin species at 6 developmental stages. Each file is named according to the following code: XxYy_chrZ.bedgraph.gz Xx: Species abbreviation He: Heliocidaris erythrogramma Ht: Heliocidaris tuberculata Lv: Lytechinus variegatus Yy: Developmental stage EE: early cleavage ME: mid cleavage LE: late cleavage B: hatched blastula G: mid gastrula L: early larva chrZ: name of chromosome for each bedgraph file; e.g. chr4 = chromosome #4 1-21 for the Heliocidaris species 1-19 for Lytechinus variegatus liftOver_ATAC_bams.tar.gz: ATAC-seq data in BAM format of liftOver alignments from each sea urchin species, referenced in the H. erythrogramma genome, for 6 developmental stages Each file is named according to the following code: XxYyZ_sorted.bam Xx: Species abbreviation He: Heliocidaris erythrogramma Ht: Heliocidaris tuberculata Lv: Lytechinus variegatus Yy: Developmental stage EE: early cleavage ME: mid cleavage LE: late cleavage B: hatched blastula G: mid gastrula L: early larva Z: biological replicate ID ranging from 3 (a-c) to 6 (a-f) replicates