postdentary bones (which in early mammals form the middle ear bones) would have needed to become detached from the dentary (jawbone); the gorgonopsian fossil record seems to indicate the postdentary-dentary connection was reduced. Though, given the specialisations required for biting, the condition of an isolating quadrate in gorgonopsians could alternatively be explained as streptostyly (rotatable quadrate) in order to widen the gape rather than facilitate hearing. Thermoregulation A major anatomical shift occurred between earlier pelycosaurs and therapsids, which is postulated to have been related to an increasing metabolism and the origins of homeothermy (maintenance of a high body temperature). The evolution of a secondary palate, and the separation of the mouth from the nasal cavity, may have increased ventilation efficiency associated with high levels of aerobic activity; gorgonopsians did not have a bony secondary palate, but possibly had one of soft tissue. Nonetheless, the secondary palate could have instead aided in eating large quantities of food at once rather than in ventilation. The reorganisation of the skeleton (from a sprawling to a parasagittal gait) has been postulated to be indicative of the presence of a diaphragm, and thus also enhanced ventilation for aerobic activity; but it could have instead been to increase acceleration or agility, which does not necessarily equate to intense aerobic activity, much like in crocodiles. Fibrous lamellar cortical bone, which all early therapsids had, would indicate an increased growth rate, but this may not be linked to metabolic rate. Modern large reptiles naturally give off body heat at a slower rate than smaller ones, and are considered "inertial homeotherms", but they maintain a low body temperature of . If therapsids required a higher body temperature of , they would either have needed to have been endotherms (generating their own body heat) or have had greater control over heat loss (that is, better homeothermy). The parasagittal gait may have aided the latter, as it would have kept most of the body off the ground as well as allowed blood to stay in the abdomen instead of having to circulate through the appendages, both of which would reduce heat transfer to the ground and stabilise core temperature. The reduced tail would have also reduced the total surface area of the animal, further minimising heat loss. Among therapsids, only eutheriodonts (not gorgonopsians) have respiratory nasal turbinates, which help retain moisture while breathing in large quantities of air, and its evolution