show Abstracthide AbstractSnakes are a diverse and important group of vertebrates. However, relationships among the major groups of snakes have remained highly uncertain, with recent studies hypothesizing very different (and typically weakly supported) relationships. Here, we address family-level snake relationships with new phylogenomic data from 3,776 nuclear loci from ultraconserved elements (1.34 million aligned base pairs, 52% missing data overall) sampled from 29 snake species that together represent almost all families, a dataset ~100 times larger than used in previous studies.