Mammals 3 cm 20 g 30 m 135

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