Late Eocene deposits of the Samlat Formation, south of Ad-Dakhla city, southwestern
Morocco, have yielded a mixed marine and terrestrial vertebrate fauna. Abundant and
diversified chondrichthyans and archaeocete whales have been found, as well as the
remains of sirenians and proboscideans. Here we describe the rest of this fossil assemblage
which includes actinopterygians, turtles, palaeophiid snakes, crocodiles and pelagornithid
seabirds. Actinopterygians are represented by at least two large-sized taxa, a scombroid
probably close to the extant Acanthocybium or to the Eocene Aramichthys, and a siluriform
related to the Ariidae. Turtles include at least four species represented by shell
fragments. This mixed coastal and continental turtle fauna includes one littoral species
of Podocnemididae, one or two deep-sea species of Dermochelyidae and one deep-sea
species of Cheloniidae. Another turtle species is assigned to the terrestrial Testudinidae.
Fragmentary crocodilian remains indicate the presence of undetermined eusuchians tentatively
referred to Gavialidae and/or to Crocodylidae. Snake vertebrae are tentatively attributed
to the genus Pterosphenus (Palaeophiidae) pending the discovery of new material. Avian
remains belong to a large pseudo-toothed bird (Pelagornithidae). Pseudo-tooth morphology
resembles that of the late Oligocene - Neogene genus Pelagornis. Additional bird remains
are needed for a more precise taxonomic assignment. The fossil assemblage and palaeoenvironment
of the upper Eocene deposits of the Samlat Formation appear closely related to those
of the upper Eocene - lower Oligocene deposits of the Fayum (Egypt). The initial overview
of this fauna provides an important contribution to the study of vertebrate evolution
in North Africa near the Eocene-Oligocene transition.
