While the maxilloturbinates of mammals are located in the path of airflow to collect moisture, sensory turbinates in both mammals and reptiles are positioned farther back and above the nasal passage, away from the flow of air. Glanosuchus has ridges positioned low in the nasal cavity, indicating that it had maxilloturbinates that were in the direct path of airflow. The maxilloturbinates may not have been preserved because they were either very thin or cartilaginous. The possibility has also been raised that these ridges are associated with an olfactory epithelium rather than turbinates. Nonetheless, the possible presence of maxilloturbinates suggests that Glanosuchus may have been able to rapidly breathe without drying out the nasal passage, and therefore could have been an endotherm.The bones of nasal turbinates are very fragile and seldom survive as fossils. In particular none have been found in fossil birds. But there is indirect evidence for their presence in some fossils. Rudimentary ridges like those that support respiratory turbinates have been found in advanced Triassic cynodonts, such as Thrinaxodon and Diademodon. This suggests that they may have had fairly high metabolic rates. The paleontologist John Ruben and others have argued that no evidence of nasal turbinates has been found in dinosaurs. All the dinosaurs they examined had nasal passages that they claimed were too narrow and too short to accommodate nasal turbinates, so dinosaurs could not have sustained the breathing rate required for a mammal-like or bird-like metabolic rate while at rest, because their lungs would have dried out.
In anatomy, a nasal concha (), plural conchae (), also called a nasal turbinate or turbinal, is a long, narrow, curled shelf of bone that protrudes into the breathing passage of the nose in humans and various animals. The conchae are shaped like an elongated seashell, which gave them their name (Latin concha from Greek κόγχη). A concha is any of the scrolled spongy bones of the nasal passages in vertebrates.In humans, the conchae divide the nasal airway into four groove-like air passages, and are responsible for forcing inhaled air to flow in a steady, regular pattern around the largest possible surface area of nasal mucosa. As a ciliated mucous membrane with shallow blood supply, the nasal mucosa cleans and warms the inhaled air in preparation for the lungs. A rapidly dilating arteriolar circulation to these bones may lead to a sharp increase in the pressure within, in response to acute cooling of the body core. The pain from this pressure is often referred to as "brain freeze", and is frequently associated with the rapid consumption of ice cream. The shallowness of the venous blood supply of the mucosa contributes to the ease with which nosebleed can occur. Structure
Conchae are composed of pseudostratified columnar, ciliated respiratory epithelium with a thick, vascular, and erectile glandular tissue layer. The conchae are located laterally in the nasal cavities, curling medially and downward into the nasal airway.