Back to Lecture 24

BACK TO DINOSAURS 2001 HOME PAGE

Lecture 25
Cenozoic, the Evolution of Humans, and our Present Condition

THIS IS AN OUTLINE, MORE TO COME

I. Terminal Cretaceous A. Extinction of the non-bird Dinosauria B. At the time small dinosaur niche was occupied by birds So the large dinosaurs died out C. Mass extinctions in Ocean

D. Pattern and causation described in the next lecture.

 II. Paleogene (65 - 25 Ma) A. Mammals, crocodilians, frogs, salamaders, apodans, lizards, snakes, turtles, sphenodontians (and champsosaurs), as well as birds were the only survivors of terrestrial vertebrates.

B. Suriving mammals were all insectivores, smally animal carnivores, or omnivores.

C. Mammals quickly evolved into a large variety of forms - some quite large.

D. Some birds became very large and flightless - Diatryma. Perhaps a return to the large dinosaur niche.

E. By end of Paleogene all major groups of mammals well established.

F. Some mmmals attained saurpod dimensions (e. g. Indricitherium).

G. Paleogene warment time in Cenozoic, parts probably warmer than Cretaceous.
 
 

 III. Neogene (25 Ma - Present A. Evolution of grasses - super-plants.
 
 

B. Herbivores follow with specialized grazing adaptations.

C. Possible implications for climate, which headed into Ice House conditions, where we remain today (for now).
 
 

D. Final separation of continents leads to evolutionary divergence on island continents and much parallel evolution of body forms in marsupial and placental mammals.

These are natural experiments in which, from the same starting points, different, even distantly related linages (e. g., placentals vs. marsupials) evolve along separate paths with surprisingly similar results. E. Hominoids present by 4.0 Ma. IV. Noosphere

V. Current Crises

A. CO2 and Global warming

B. Biodiversity Crisis
Go to Lecture 26 - The Practice final and Review

BACK TO SYLLABUS

BACK TO THE DINOSAUR AND THE HISTORY OF LIFE HOME PAGE