Mammals 3 cm 20 g 30 m 135 Slides: 39 Download presentation Mammals 3 cm 20 g 30 m 135, 000 kg Mammals ROUSs Mammals Myotis grisescens Mammals Mammals Mammals Mammals Mammals Mammal s Evolution of the mammals the Triassic… Evolution of the amniotes ? ? anapsids synapsids diadectomorphs Seymouria amniotes reptilomorph ancestor Evolution of the mammals pelycosaurs “mammal-like reptiles” synapsid ancestor Evolution of the mammals Mammal-like reptiles… Thecodont Synapsid Short but tall skull braincase… Q-A jaw articulation Initially… Pelycosaurs: Edaphosaurus Pelycosaurs: Dimetrodon Evolution of the mammals “non-cynodont” pelycosaurs therapsids “mammal-like reptiles” synapsid ancestor Evolution of the mammals squamosal quadrate articular non-cynodont therapsids: Lycaenops dentary partially heterodont minimal secondary hard palate larger temporal fenestra shorter, taller postorbital skull Quadrate - articular jaw joint Intermediate posture Mostly carnivores Relatively large body size Evolution of the mammals “non-mammalian” “non-cynodont” pelycosaurs cynodonts therapsids “mammal-like reptiles” synapsid ancestor Evolution of the mammals Cynodonts: Thrinaxodon Evolution of the mammals incisors, canines, molars partial secondary hard palate large temporal fenestra shorter, taller postorbital skull Turbinate bones Upright posture Carnivores Smaller body size Hair? E/H? pelycosaur cynodont Evolution of the mammals “non-mammalian” mammals “non-cynodont” pelycosaurs cynodonts therapsids “mammal-like reptiles” synapsid ancestor Evolution of the mammals heterodont hard palate temporal fenestra Mammals: Morganucodon short, tall postorbital skull upright posture small body size late Triassic… Evolution of the mammals Dentary-squamosal 3 “middle ear ossicles” articular=malleus quadrate=incus hyomandibular=stapes mammary glands diphyodont dentition alveolated lung 4 -chambered heart hair E-H Evolution of the mammals 3 “grades” Monotremes Evolution of the mammals Monotremes Evolution of the mammals Marsupials Choriovitelline placenta: Bilaminar omphalopleure mesoderm of area vasculosa Evolution of the mammals Eutherians Chorioallantoic placenta: chorionic ectoderm and mesoderm, allantoic endoderm and mesoderm