Airflow comparison between the straightened airway and the ST airway in Euoplocephalus tutus (AMNH 5405).

(A) Dorsal view of the skull of E. tutus with the left ST airway in situ. (B) Dorsal view of the straightened airway with flow lines in place. Airflow lines are color-coded for temperature (hotter colors = hotter temperatures). Inset: Magnified region of nasal vestibule showing evenly spaced, straight flow lines. (C) Dorsal view of the ST airway under the low flow scenario showing the presence of vorticity throughout the nasal vestibule. Note: ST airway in C is not to scale with straightened airway B.