Figure 1. A in The origin of mammalian endothermy: a paradigm for the evolution of complex biological structure

Figure 1. A, reconstruction of the skeleton of the therocephalian therapsid Regisaurus in lateral and dorsal views (from Kemp, 1986). B, internal view of the nasal cavity of the therocephalian Glanosuchus (from Hillenius, 1994). Abbreviations: etht?, possible ethmo-turbinal ridge; mxt?, possible maxillo-turbinal ridge; nt?, possible naso-turbinal ridge.