The New World coral snakes (micrurines), genera Micrurus and Micruroides have recently been seen as derived from a lineage of South American colubrids, rather than from a common lineage with Old World elapids and sea snakes as traditionally accepted. We compared serum albumins of representative coral snakes, Old World elapids, sea snakes, and neotropical colubrids immunologically. Phylogenetic analysis of the biochemical data unambiguously allies the micrurines with the family Elapidae as it is currently understood. Using the albumin molecular clock calibration derived from other terrestrial vertebrates. we suggest a late Oligocene-early Miocene separation between the New and Old World elapid lineages. This requires a movement of elapid stocks from Asia into North America, and supporting evidence for this model is derived from several paleontological sources. We suggest that a number of extant micrurine lineages have had long independent histories.