New theropod remains from the Tiourarén Formation (?Middle Jurassic, Niger) and their bearing on the dental evolution in basal tetanurans

摘要: Abstract A fragment of a maxilla and isolated theropod teeth from the (?) Middle Jurassic Tiouraren Formation are described. The specimens come Tadibene, in rural community Aderbissinat, Thirozerine Department, Agadez Region, Niger. They were identified through direct comparison with previously described literature as well on basis discriminant morphometric analyses. Our results suggest they belong to Ceratosauridae, Megalosauridae, oldest representatives Spinosauridae. analyzed sample shows some uncommon characters, such spinosaurid-like ornamentation megalosaurid-like teeth, or low number denticles, which sheds light tooth morphology dental evolution basal tetanurans early spinosaurids.