Cenozoic

• Paleogene Period


  66 million years ago to 23 million years ago

  • Means "old arising" in Greek

  • Includes:

  • Paleocene—66 million years ago to 56 million years ago • "Oldrecent"

  • Eocene—56 million years ago to 34 million years ago • "Dawnoftherecent"

  • Oligocene—34 million years ago to 24 million years ago • "fewrecent"
• Neogene


  23 million years ago to 2.6 million years ago

  • Means "new arising" in Greek• Interval of time when the modern world takes shape

  • Includes:

  • Miocene—23 million years ago to 5.3 million years ago • "Less recent"

  • Pliocene—5.3 million years ago to 2.6 million years ago • "Morerecent"
• Quaternary


  2.58 million years ago to present. Includes

  • Pleistocene—2.58 million years ago to 12 000 years ago • "Mostnewest"

  • Holocene—last 12 000 years • "Entirelynew"
• Paleogeography


  The continents were moving closer to their modern positions by the end of the Cretaceous
• A few major movements of the plates would occur in the Cenozoic


  • Collision of India with Asia

  • Rifting of North America from Europe

  • Creation of the Caribbean plate and connection between North and South America
• Miocene


  Central America and the Caribbean started to look much like it did today by the ________. Himalayan Mountains were created during this as well.
• Eocene


  Rifting of North America from Europe would connect the Arctic and Atlantic oceans in the
• Laramide orogeny


  began on the western margin of North America in the latest Cretaceous and would continue through to the end of the Eocene
• Climate


  In general, the Cenozoic was much cooler than the Paleozoic or Mesozoic
• Two main climatic trends


  1.Warming through the Paleocene and Eocene ended by a sudden interval of

  cooling in the Oligocene

  2.A warming in the Miocene but then cooling until today
• 1. An interval of warming through the Paleocene and Eocene


  Arctic had a climate similar to the subtropical zone today

  Deep waters became dysoxic
• Paleocene-Eocene warming event


  was a sudden warming event within the overall warming trend. Marked by a sudden shift in stable oxygen isotope ratios in foraminifera
• 2. A gradual cooling through Miocene to today


  pulse of cooling through the Oligocene followed by a more gradual trend starting in the Miocene

  Became drier as well
• Younger Dryas


  Period of global cooling that occurred 12,000 years ago
• Example of positive feedback


  Isotope analyses suggests that Greenland may have warmed by as much as 7 degrees in only 3 years
• Angiosperms (flowering plants)


  became more diverse than gymnosperms as the Cenozoic continued
• Radiation of mammals


  With the disappearance of large terrestrial reptiles, there were empty niches

  in the ecosystem

  • Mammals evolved to fill these niches quickly in the early Cenozoic through an adaptive radiation
• Odd-toed ungulates


  diversified before even-toed ungulates

  • E.g.Hyracotherium• Related to horses, tapirs, and rhinoceroses

  today
• Even-toed unglulates


  didn't diversify until the end of the Eocene and into the Oligocene

  • E.g.Diacodexis

  • Cattle, deer, antelopes, sheep, goats, pigs, bison, camels
• Great American Biotic Interchange


  occurred when the Isthmus of Panama formed, allowing organisms from North and South America to disperse out of their continent of origin.
• Human evolution


  Some primates were becoming increasingly terrestrial in the Miocene, but still retained monkey-like features (e.g. Proconsul)
• Miocene


  Apes (Family Hominidae) diversified in the
• Australopithecus


  the earliest humanlike creature that flourished in eastern and southern Africa 3 to 4 million years ago
• Homo eructus


  Definition: "upright walking humans", which existed from 2 million to 200,000 years ago; used cleavers, hand axes and learned how to control fire

  Importance: domesticated fire for food and protection
• Homo antecessor


  An extinct human species (or subspecies) dating from 1.2 million to 800,000 years ago found in 2 caves (sima del elephante for the older & gran dolina for the younger) in atapuerca, spain; these are the oldest hominin found in western Europe.
• Homo heidelbergensis


  A transitional species between Homo erectus and Homo sapiens
• Homo neanderthalensis


  the species before us homo sapiens; lived form 30,000 to 300,000 years ago; they were stronger and had bigger brains
• Homo sapiens


  modern humans
• Cro-Magnon


  a species also referred to as Homo Sapiens; seem to have replaced Neanderthals
• Anthropocen


  A new epoch defined as the point at which humans started to have an effect on the planet, rather than the first/last occurrence of a fossil