Class 02 - Sept 1

E laying eggs when where did it all begin the origin

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Unformatted text preview: pposed to externally, i.e. laying eggs When & where did it all begin? The origin of mammals Chara teristics (hom othermy, heterodontism, lactation, internal gestation) Hadrocodium (China, early Jurassic ~195mya) Monotremes Marsupials Multituberculates Our closest relatives? dermopterans Gliding mammals 4 main groups MONOTREME: egg-laying mammals E.g. Platypus MARSUPIALS: mammals w/ pouches E.g. Kangaroos MULTITUBERCULATES: rodent like mammals; became extinct during Oligocene EUTHERIA: Placental mammals and all extinct mammals more closely related to living placentals than to living marsupials. E.g. Humans 1 IB35ac fall 2009, class #2 "tyranny of the present" tyranny present Always beware the Scotese, C.R., 2002, http://www.scotese.com, (PALEOMAP website). we who live in the present are blissfully unaware of the past ->Extinct Order of Mammals ->Closely related to primates or precursor to them GEOLOGIC TIMESCALE: -> K-T Mass Extinction - (66 mya) -> Paleocene - (66-56 mya) -> Eocene - (55-34 mya) -> Oligocene - (34-23 mya) -> Mioc...
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