ZOOLOGY STUDY GUIDE - Ye. O. Nevedomska - 2013
LECTURE 1. DIVERSITY OF THE ORGANIC WORLD
3. A Brief History of the Animal Kingdom
A BRIEF HISTORY OF the animal kingdom is presented in Table 3.
Class="center">Table 3
A BRIEF METABOLISM/13.html">History of the ANIMAL KINGDOM
Era and its duration (in million years) |
Period and its duration (in million years) |
Epoch and its duration (in million years) |
Life forms |
1 |
2 |
3 |
4 |
Precambrian (3500) |
Origin of prokaryotes (3.5 billion years ago), Unicellular Eukaryotes (about 1.5 billion years ago), multicellular eukaryotes (about 700 million years ago): Coelenterates. |
||
Cambrian (70) |
Origin of polychaetes, Arthropods, and Chordates. |
||
Ordovician (60) |
Flourishing of giant Mollusks and trilobites; appearance of coral polyps, eurypterids, and jawless chordates — ostracoderms. |
||
Paleozoic (330) |
Silurian (30) |
Appearance of the first fish — placoderms and acanthodians. Flourishing of oligochaetes, arachnids, and myriapods. |
|
Devonian (50-70) |
Cartilaginous fish appear in the seas, and bony fish (lobe-finned and lungfish) in fresh waters. Colonization of land by vertebrates. Appearance of the first amphibians. |
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Carboniferous (70) |
Flourishing of amphibians. Appearance of insects, terrestrial gastropods, and reptiles. |
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Permian (45) |
Increase in reptile diversity (squamates, turtles, pelycosaurs, therapsids). Extinction of trilobites and acanthodians (due to a drier and colder climate), as well as a significant portion of lungfish, lobe-finned fish, and primitive amphibians. |
||
Triassic (45) |
Diversity of cartilaginous and bony fish, and mammal-like reptiles (dinosaurs) increases. Appearance of mammals. Extinction of primitive amphibians. |
||
Mesozoic (173) |
Jurassic (58) |
Flourishing of cephalopods (ammonites and belemnites) and reptiles. Appearance of anurans, caudates, and birds. |
|
Cretaceous (70) |
Flourishing of marine foraminifera. Appearance and dominance of insects. Extinction of dinosaurs at the end of the period. Appearance of marsupial and placental mammals. |
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Paleocene (8) |
Dinosaurs went extinct. Appearance of carnivorous mammals, rodents, lagomorphs, and ancestors of ungulates. |
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Paleogene (40) |
Eocene (20) |
Wide adaptive radiation of mammals and birds. |
|
Oligocene (12) |
Most modern bird orders appear. Flourishing of ungulates, proboscideans, and monkeys. |
||
Cenozoic (60-70) |
Neogene (23) |
Miocene (15) |
Appearance of the first hominoids (apes). |
Pliocene (8) |
Formation of a fauna that closely resembles the modern one. |
||
Quaternary (2) |
Pleistocene (2) |
Appearance of Homo erectus. |
|
Holocene (0.01) |
Appearance of modern humans. Their active economic activity has shaped the modern appearance of planet Earth. |
Last update: 14/08/2026
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