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Birth of the modern world: the Tertiary |
1 Department of Palaeontology, Natural History Museum, Cromwell Road, London, SW7 5BD, UK (e-mail: s.young{at}nhm.ac.uk)
2 40 Bruce Avenue, Hornchurch, Essex, RM12 4JE, UK (e-mail: bobfosswilliams{at}hotmail.com)
Two neurocrania of the eel genus Echelus Rafinesque, 1810 were collected from the London Clay Formation, Eocene, from Aveley, Essex. They are identified herein as E. branchialis Woodward, 1901. One specimen retains an incomplete premaxillary ethmo vomerine plate, normally lost in fossil specimens, and provides further anatomical information and taxonomic characters for this species.
The geographical range of the species is extended and localities of fossil species of Echelus and other fossil taxa believed by various authors to be closely-related to Echelus species are depicted on a map of the distribution of continental crust in the northern hemisphere during Oligocene times. The distribution of such eel taxa is consistent with the supposed extent of the Eocene sea within Europe. It would appear that modern species of Echelus now occupy areas that are more cosmopolitan than the fossil species. During the break-up of Pangaea and the subsequent expansion of the Atlantic and Indo-Pacific Oceans species of Echelus have ventured beyond their original provenance of continental sea and now occupy habitats along margins of the eastern Atlantic and of the western and eastern Indo-Pacific Oceans.