 On the inner surface of the nasal section of skull are ridges called nasoturbinals , which may have supported cartilage that increased the area of the olfactory epithelium , the layer of tissue that detects odors . These ridges are much smaller than those of later synapsids from the Late Permian and Triassic , whose large nasoturbinals are taken as evidence for warm @-@ bloodedness because they may have supported mucous membranes that warmed and moistened incoming air . Thus , the nasal cavity of Dimetrodon is transitional between those of early land vertebrates and mammals . 
