sign in sign up
<<
Home , Repenomamus, Tritheledontidae

Tracking Human Evolution: Where Do We Fit on the Tree of Life? Geology 230 Fossils and Evolution Amniota http://tolweb.org/Amniota/14990 Crocodiles hatching from their amniote eggs Pennsylvanian anapsid or stem Amniote Family Tree

Prothero, 2007 Skull: one Diapsid Skull: two opening behind the openings behind the orbit (eye) orbit (eye) Synapsida http://tolweb.org/Synapsida/14845 , Germany synapsid : or -like reptiles Therapsida, and extinct relatives http://tolweb.org/Therapsida/14973

Biarmosuchia Eotitanosuchia Dinocephalia Anomodontia Theriodontia Gorgonopsia Therocephalia Cynodontia Diviniidae Mammalia Procynosuchidae Galesauridae Thrinaxodontidae Cynognathidae gomphodonts Chiniquodontidae Probainognathidae Tritheledontidae (Ictidosauria) A Gallery of Therapsids From Synapsids to Mammals, a well documented transition series

Prothero, 2007 Carl Buell Prothero, 2007 Multiple bones in the lower jaw of the dino T. rex. Yanoconodon, Lower Mammal from China Yanoconodon, Lower Cretaceous of China, retains ear bones attached to inside lower jaw

Morganucodon

Yanoconodon Human Ear Bones, or Auditory Ossicles

Cochlea Mammalia http://tolweb.org/Mammalia/15040 Class Mammalia - to Recent Superorder Tricodonta - Late Triassic to Late Cretaceous Superorder - Late to Early Oligocene Superorder Monotremata - to Recent Superorder () - Late Cretaceous to Recent Superorder (Placentals) - Late Cretaceous to Recent Evolution of Mammalian Superorders

Metatheria Eutheria (Marsupials) (Placentals)

. Live Birth

Extinct: U . .. Mammary Glands? Mammals in the Age of , a lower Jurassic mammal with a “large” brain (6 mm brain case in an 8 mm skull) Lower Cretaceous mammal from China Jawbones of a Cretaceous from Mongolia Mammal fossil from the Cretaceous of Mongolia Early Cretaceous mammal ate small dinosaurs

Repenomamus robustus fed on psittacosaurs. Image: Xu Xiaping, 2005 Repenomamus robustus Repenomamus robustus with psittacosaur in the gut Modern Elephant Shrew Weasel hunting at night Bats, such as this vampire bat, hunt at night

Monotremes: adult

The Platypus baby egg

Monotremes: The Echidna Typical Marsupial, a Kangaroo Poorly developed newborn kangaroo attached to a nipple in the pouch. Eutheria http://tolweb.org/Eutheria/15997 Primate Classification- 1980’s

Order Primates Suborder Prosimii: tarsiers and lemurs Suborder Anthropoidea: monkeys, apes, and hominids Superfamily Hominoidea Family Pongidae: great apes Family Hominidae: Homo and hominid ancestors Primate Classification – 2000’s Order Primates Suborder Prosimii: tarsiers and lemurs Suborder Anthropoidea: monkeys, apes, and hominids Superfamily Hominoidea Family Hominidae: all hominoids except gibbons Subfamily Ponginae: orangutans Subfamily Homininae: gorillas, chimps, Homo and hominin ancestors 100% % genetic similarity 96% with humans 95% 98%

84%

58%

91%

Prothero, 2007 Tarsiers, a primitive Primate (Prosimian) from Southeast Asia. Tarsier sanctuary, Philippines A Galago or bush baby, a primitive Primate (Prosimian) from Africa. A Slow Loris, a primitive Primate (Prosimian) from Southeast Asia. Check out the fingers. Lemurs, primitive Primates (Prosimians) from Madagascar. Monkeys, such as baboons, have tails and are not hominoids. Proconsul, the oldest hominoid, 18 MY Hominoids The Orangutan, a Great Ape from Southeast Asia. Gorillas, Great Apes from Africa. Chimpanzees, Great I’m cool Apes from Africa. Neoteny in Human Evolution. Humans resemble baby apes more than adult apes. Humans are said to be paedomorphic. Chimp skull on the left, human skull on the right Chimp

Homo sapiens

Consequences of Neoteny

• Large brain and cranium • Small jaws and teeth with small face • Retention of juvenile growth patterns • Long juvenile period = extended learning • Retardation of onset of puberty • Longer life span • Naked skin Next: The Hominid Fossil Record