Table of Contents:
Introduction (0:00)
The First Synapsids In The Paleozoic (0:38)
Mammal Ancestors In The Mesozoic And The First True Mammals(3:47)
Monotremes (9:29)
Eutheria (10:51)
Marsupials (11:45)
Placentals (17:08)
Placentals: Atlantogenata (17:57)
Placentals: Euarchontoglires (20:38)
Placentals: Laurasiatheria (28:15)

Mammals are a fascinating group of animals that can be found everywhere on Earth, from the land to the seas to the skies. From small rodents like mice and rats to behemoths like elephants and whales, mammals are found in all kinds of shapes and sizes, occupying numerous environmental niches. This rich grouping of animals comprises a vast network of different lineages and in this video I want to explain the origins and the spread of mammals. As such this video will be broken up into two parts: in the first I will cover the evolution of mammals, and in the second I’ll be going over the major extant orders and explaining every living mammalian family.

Image Credits:
WillemSVDMerwe
Julio Lacerda

Sources:
Handbook of the Mammals of the World
Steve Brusatte

Twitter:   / animalorigins