origin and evolution of species [3]![click to hear](/images/speaker.jpg)
Since its formation some 4.6 billion years ago, the Earth has witnessed the genesis of continents and oceans and the appearance of animals and vegetation.
Permian ![click to hear](/images/speaker.jpg)
Geological period marked by the predominance of reptiles and amphibians. The continental mass now formed into a great protocontinent: Pangea.
mesosaur ![click to hear](/images/speaker.jpg)
First aquatic reptile with long sharp teeth and a powerful tail allowing it to propel itself in shallow water.
dimetrodon ![click to hear](/images/speaker.jpg)
Carnivorous reptile fossil with dorsal spines connected by a membrane to regulate its internal temperature; dominant in the Permian period.
Jurassic ![click to hear](/images/speaker.jpg)
Geological period during which the dinosaurs ruled the world. The Atlantic Ocean was formed at this time.
ichthyosaur ![click to hear](/images/speaker.jpg)
Swift carnivorous marine reptile; it had certain dolphin characteristics and reached 33 feet in length. It disappeared during the Cretaceous period.
archaeopteryx ![click to hear](/images/speaker.jpg)
Animal fossil capable of flight; it had certain characteristics of a reptile (claws, teeth, long bony tail) and others of a bird (wings, feathers).
plateosaur ![click to hear](/images/speaker.jpg)
One of the largest dinosaurs of the Jurassic period. This long-necked herbivore stood upright on its hind legs to reach the leaves of trees.
Triassic ![click to hear](/images/speaker.jpg)
Geological period marked by the breaking apart of the great protocontinent, the formation of today’s continents and the appearance of mammals.
nothosaur ![click to hear](/images/speaker.jpg)
Carnivorous amphibious dinosaur fossil with short finlike limbs adapted to move on land and in the water.
coelophysis ![click to hear](/images/speaker.jpg)
Two-legged carnivorous dinosaur, extremely agile and fleet of foot, with powerful claws.
megazostrodon ![click to hear](/images/speaker.jpg)
About the size of a mouse, one of the first mammals to appear on Earth was a mainly nocturnal insectivore.