Mammalian petrosal from the Lower Cretaceous high paleo-latitude Teete locality (Yakutia, Eastern Russia)

Abstract A mammalian petrosal from the Lower Cretaceous Teete locality in Yakutia (Russia) shows a prominent and complex system of venous channels bony wall pars cochlearis surrounding straight cochlear canal. This is distinctive more strongly developed than other petrosals. ridge present on ventral side canal endocast, continuing between fenestra vestibuli cochleae anterior direction. corresponds to position scala tympani, similar secondary lamina crown therians, but lacks sharp laminar edge. The separate for aquaeductus (derived), retains deep sulcus that resembles perilymphatic (plesiomorphic). oval shaped deep. with eutriconodontans like Priacodon fruitaensis Upper Jurassic North America. However, thick extensive are otherwise known docodontans. In even developed, resemble pattern recently reported possible haramiyidan petrosals Middle western Siberia (Russia). Both eutriconodontan dental remains beside tritylodontids