Tracking Human Evolution: Where Do We Fit on the Tree of...
Transcript of Tracking Human Evolution: Where Do We Fit on the Tree of...
Synapsid Skull: one opening behind the orbit (eye)
Diapsid Skull: two openings behind the orbit (eye)
Therapsida, Mammals and extinct relatives http://tolweb.org/Therapsida/14973
BiarmosuchiaEotitanosuchiaDinocephaliaAnomodontiaTheriodontia
GorgonopsiaTherocephaliaCynodontia
DiviniidaeMammaliaProcynosuchidaeGalesauridaeThrinaxodontidaeCynognathidaegomphodontsChiniquodontidaeProbainognathidaeTritheledontidae (Ictidosauria)
Yanoconodon, Lower Cretaceous of China, retains ear bones attached to inside lower jaw
Morganucodon
Yanoconodon
Class Mammalia - Late Triassic to RecentSuperorder Tricodonta - Late Triassic to Late
CretaceousSuperorder Multituberculata - Late Jurassic to
Early OligoceneSuperorder Monotremata - Early Cretaceous
to RecentSuperorder Metatheria (Marsupials) - Late
Cretaceous to RecentSuperorder Eutheria (Placentals) - Late
Cretaceous to Recent
Evolution of Mammalian Superorders
Eutheria
(Placentals)
Metatheria
(Marsupials)
Live Birth
Mammary Glands?.
.
Monotremes
..
Extinct: U
Repenomamus robustus
fed on psittacosaurs.
Image: Xu Xiaping, 2005
Early
Cretaceous
mammal ate
small
dinosaurs
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’sOrder 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
A Slow Loris, a
primitive Primate
(Prosimian) from
Southeast Asia.
Check out the
fingers.
Neoteny in Human Evolution. Humans
resemble baby apes more than adult
apes. Humans are said to be
paedomorphic.
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