The world-famous upper Miocene fossil localities on the Aegean island of Samos in
Greece have produced a rich fossil record that sheds light on the evolution of eastern
Mediterranean terrestrial faunas over a one-million-year interval of the late Neogene.
Fossils have been discovered on Samos since antiquity, although a succession of paleontological
and commercial collecting expeditions over the last 130 years has resulted in specimens
now being distributed throughout museums all over the world. Here, we survey the fossil
tortoise remains from Samos, which are significant because they include early antecedents
of the modernTestudolineage, together with spectacular examples of the European Neogene
gigantic testudinid dagger Titanochelon, which represents one of the largest-bodied
terrestrial turtle taxa documented to date. All of the Samos fossils derive from the
Mytilinii Formation, which spans the late MN11-early MN13 Neogene land mammal zones.
The small-bodied tortoise remains include two incomplete shells that are morphologically
consistent with basal testudonans and phylogenetically distinct from the coeval speciesTestudo
marmorumfound on mainland Greece. The Samos gigantic tortoise dagger'Testudo'schafferiwas
based on a spectacularly large skull and femur. However, we describe new plastron
fragments, limb elements, and osteoderms that are compatible with dagger Titanochelonspecimens
from southern Greece and Anatolia. This could imply faunal links with the distinctive
'Pikermian' local assemblages from Asia Minor and concurs with the proposed late Miocene-Pliocene
biogeographic segregation of large mammals from the eastern Aegean margin and Turkey
relative to those occurring in northwestern Greece and the Balkan Peninsula.
