First Record of Late Triassic Vertebrate Fossils from Lithuania and the Paleobiogeography of Phytosaurs

Brusatte, S. L., Butler, R. J., Niedźwiedzki, G., Sulej, T., Bronowicz, R., and J. Satkūnas. 2012. First record of Mesozoic terrestrial vertebrates from Lithuania: phytosaurs (Diapsida: Archosauriformes) of probable Late Triassic age, with a review of phytosaur biogeography. Geological Magazine (early online) 13 pp. doi:10.1017/S0016756812000428

Abstract – Fossils of Mesozoic terrestrial vertebrates from Lithuania and the wider East Baltic region
of Europe have previously been unknown.We here report the first Mesozoic terrestrial vertebrate fossils
from Lithuania: two premaxillary specimens and three teeth that belong to Phytosauria, a common
clade of semiaquatic Triassic archosauriforms. These specimens represent an uncrested phytosaur,
similar to several species within the genera Paleorhinus, Parasuchus, Rutiodon and Nicrosaurus.
Because phytosaurs are currently only known from the Upper Triassic, their discovery in northwestern
Lithuania (the Šaltiškiai clay-pit) suggests that at least part of the Triassic succession in this region
is Late Triassic in age, and is not solely Early Triassic as has been previously considered. The new
specimens are among the most northerly occurrences of phytosaurs in the Late Triassic, as Lithuania
was approximately 7–10◦ further north than classic phytosaur-bearing localities in nearby Germany and
Poland, and as much as 40◦ further north than the best-sampled phytosaur localities in North America.
The far northerly occurrence of the Lithuanian fossils prompts a review of phytosaur biogeography
and distribution, which suggests that these predators were widely distributed in the Triassic monsoonal
belt but rarer in more arid regions.