Mammals 3 cm 20 g 30 m 135







































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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