are found on both continents. Tyrannosaurid fossils have been found in Alaska, which may have served as a land bridge allowing dispersal between the two continents. Non-tyrannosaurid tyrannosauroids like Alectrosaurus and possibly Bagaraatan were contemporaneous with tyrannosaurids in Asia, while they are absent from western North America. Eastern North America was divided by the Western Interior Seaway in the middle of the Cretaceous and isolated from the western portion of the continent. The absence of tyrannosaurids from the eastern part of the continent suggests that the family evolved after the appearance of the seaway, allowing basal tyrannosauroids like Dryptosaurus and Appalachiosaurus to survive in the east as a relict population until the end of the Cretaceous. Basal tyrannosauroids have also been suggested to be present in Australia and South America during the Early Cretaceous. NMV P186069, a partial pubis (a hip bone) with a supposed distinctive tyrannosauroid-like form, was discovered in Dinosaur Cove in Victoria. However, a response suggested that critical tyrannosauroid characters were absent from the fossil. The Australian taxon Timimus, known from a femur, and the Brasilian Santanaraptor, known from a partial juvenile skeleton, have also been suggested to be tyrannosaurs. However, these placements have been considered questionable, with the supposed tyrannosauroid characters of Santanaraptor being widely distributed within Coelurosauria, in other characters having similarities to noasaurids. Paleobiology Facial tissue A conference paper by Tracy Ford states that there was rough bone texture on the skulls of theropods and higher foramina frequency than lepidosaurs and mammals which would be evidential for a sensitive snout for theropods. A study in 2017 study about a new tyrannosaurid named Daspletosaurus horneri was published in the journal Scientific Reports. Paleontologist Thomas Carr analyzed the craniofacial texture of Daspletosaurus horneri and observed a hummocky rugosity which compared to crocodilian skulls and suggesting Daspletosaurus horneri including all tyrannosaurids have flat sensory scales. The subordinate regions were analyzed to have cornified epidermis. However, a 2018 presentation has an alternative interpretation. Crocodilians don't have flat sensory scales but rather cracked cornified epidermis due to growth. The hummocky rugosity in the skulls of lepidosaurs have correlation with scales which this bone texture is also present in tyrannosaurid skulls. The foramina frequency in theropod skulls does not exceed 50 foramina which shows that theropods had lips. It's been proposed that lips are a primitive trait in tetrapods and the soft tissue present in crocodilians are a derived trait