Fig. 5 Frequency of appearances of immigrant vertebrate taxa or their oldest known descendants in opposing continents as observed in well-dated fossiliferous sediments in South and North America per million years. Frequency of appearances of immigrant vertebrate taxa or their oldest known descendants in opposing continents as observed in well-dated fossiliferous sediments in South and North America per million years. See fig. S3 for further details. Aaron O’Dea et al. Sci Adv 2016;2:e1600883 Copyright © 2016, The Authors