Timeline of the Evolution of the Major Groups of Organisms

Evolutionary Biology (BI 25) Lecture Notes



Timelines, Origin of Life and Other General Resources



Scientific American Explorations: Bugs in the Data?: 8/96

Summary Table of the Evolution of the Major Vertebrate Groups


Era Period (years) Epoch Plants Animals Geology/Climate Electronic Resources for the Major Groups Electronic Resources for Extinctions
Cenozoic Quatenary (2.5 MYA) Recent Increase in herbaceous plants Appearance of humans Ice Ages - Glacial Periods   The Holocene Mass Extinction?
          Continents in    
        Mass extinctions of large mammals and birds present positions    
  Tertiary (65 (MYA) Pleiostocene Mass extinctions   Continents still drifting    
        First Homo      
    Pliocene Grasslands replace forests Primitive hominids   Fossil Hominids  
        Bird Radiation   Introduction to the Aves  
    Miocene   First Apes      
    Oligocene   Mammal Radiation   The Hall of Mammals  
        groups present      
    Eocene   Age of bony fishes      
    Paleocene Radiation of First Placental      
      flowering plants Mammals      
        Pollinating Insects      
Era Period (years) Epoch Plants Animals Geology    
Mesozoic Cretaceous (135 (MYA)   First flowering Dinosaurs - extinction,

Marsupial Mammals

Mountain building Dinosaur Volcano Greenhouse Extinction by Dewey McLean

Alvarez asteriod theory - off Yucatan Peninsula

Marsupial Mammals

The End-Cretaceous (K-T) Extinction
      plants Ammonite Extinction Continental Drift    
  Jurassic (195 MYA)   Gymnosperms and First birds, Primitive Mammal Radiation Continents separated and Fossil Record of the Aves

Introduction to Multituberculates

      Ferns disperse Age of Dinosaurs are drifting Introduction to the Ichthyosauria  
  Triassic (240 MYA)   Gymnosperms - Radiation of dinosaurs   Pterosauria  
      dominant First Dinosaurs

dinosaurs - herbivores

dinosaurs - carnivores

Continents first


Ischigualasto Formation, Argentina

The Dinosauria

        First Primitive Mammals

earliest mammals

early mammals - herbivores

early mammals - carnivores

        Reptile Radiation   See the Archosaurs  
        Marine Arthropods      
        First beetles      
Era Period (years) Epoch Plants Animals Geology    
Paleozoic Permian (285 MYA)   Mass Extinctions Mass Extinctions Violent Geologic and The Paleozoic Era The Permian Mass Extinction
        of Marine Life      
      Decline of Decline of Amphibians Climate disturbances    
      non seed plants Appearance of Therapsid Pangea    
        Increase in Reptiles      
        and Insect      
  Carboniferous (375 MYA)   First Gymnosperms Early Reptiles Gondwanaland    
      Spread of non-seed First winged Insects      
      plants, ferns and allies        
  Devonian (420 MYA)   First seed plants Origin, diversification of   Tetrapods: Fossil Record The Devonian Mass Extinction
      Example of higher terrestrial plants Amphibians, bony fishes   Actinopterygii: Fossil Record  
  Silurian (450MYA)   First vascular plants Golden Age of fishes      
        Origin - jawed fishes   Introduction to the Chondrichthyes  
        radiation of Agnathans      
      First terrestrial plants - primitive terrestrial plants, fossil example First terrestrial invertebrates      
  Ordovician (520 MYA)     First vertebrates - fishes   Introduction to the Petromyzontiformes-Lampreys and their Allies The Ordovician Mass Extinction
        Diversification of marine invertebrates - Echinoderms      
  Cambrian (570 MYA)   Algae - dominant Trilobites dominant


  Introduction to the Trilobita

Introduction to the Brachiopoda

Burgess Shale fossils

The Cambrian Mass Extinction
      plants Explosive marine diversification   Plantae: Fossil Record - Chart of First Appearances of Major Groups  
        Cambrian explosion - First appearance of most phyla      
Era Period (years) Epoch Plants Animals Geology   The Precambrian and Vendian Mass Extinctions
Proterozoic .6 BYA   Plant-like protists   Continental Drift The Proterozoic Era  
  2 BYA   First eukaryotes     Fossil Record of the Bacteria  
  3.5 BYA - 2 BYA   Photosynthetic bacteria and stromatolites   Oxygen Atmosphere    
  3.5 BYA   First prokaryotes        
  4 BYA            
  4.5 BYA   None   Formation of the earth    


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Copyright © 2001 Jay Pitocchelli. All rights reserved. The contents of this page are the intellectual property of Dr. Jay Pitocchelli for distribution to students enrolled in Evolutionary Biology BI 25 at Saint Anselm College. These pages may not be copied, photocopied, reproduced, translated, or published in any electronic or machine-readable form in whole or in part without prior written approval of Jay Pitocchelli. Students enrolled in Evolutionary Biology BI 25 at Saint Anselm College have permission to print this material for their lecture notes.