We report the discovery in the early Eocene French locality of Le Quesnoy (MP7, Neustrian) of the first palaeanodont from the Eocene of Europe, and the first metacheiromyid from outside of western North America. The species, known from a dentary and a few postcranial bones, belongs to the genus Palaeanodon, and it is one of several North American immigrant taxa that characterize the Paleocene-Eocene faunal turnover in Europe. Palaeanodon sp. from Le Quesnoy is close in size to P. nievelti from the early Wasatchian of North America. However, it shows noticeable primitive features such as a more prominent ventral keel on the metacarpal III and a probably elongated and bilobed pc4 (= p4), although this is inferred from the infilled alveolus. Additional original features are also noticed on the tentatively referred astragalus. These minor differences suggest that the Le Quesnoy form represents a new species, but the available material remains inadequate to name it. The morphology and the size of the metacarpal are actually closer to P. parvulus (Clarkforkian)--P.nievelti (Wasatchian) intermediates, suggesting a sister-group relationship with the latter (if Palaeanodon sp. from Le Quesnoy is not shown to belong to a distinct European lineage). This would indicate a dispersal at least as old as P.nievielti and a correlation of Le Quesnoy not later than early Wasatchian. The discovery of Palaeanodon in Le Quesnoy fits paleobiogeographically well with the hypothesis of a relationship of palaeanodonts to pholidotans, which have their earliest record in the middle Eocene of Europe (Messel).

Key words: Mammalia, Palaeanodonta, paleobiogeography, Neustrian, Eocene, Le Quesnoy, Europe.

Emmanuel Gheerbrant [gheerbra@mnhn.fr] (corresponding author) and Marc Godinot [godinot@mnhn.fr], EPHE, UMR−CNRS 5143 “Paleobiodiversité et Paléoenvironnements”, Case 38, Département Histoire de la Terre, Muséum national d’Histoire naturelle, 57 rue Cuvier, 75005 Paris, France; Kenneth D. Rose [kdrose@jhmi.edu], Center for Functional Anatomy and Evolution, Johns Hopkins University School of Medicine, 1830 East Monument Street, Baltimore, MD 21205, USA.