-
The first humans emerged in Africa around two million years ago, long before the modern humans known as Homo sapiens appeared on the same continent. There's a lot anthropologists still don't know about how different groups of humans interacted and mated with each other over this long stretch of prehistory. -
Sahelanthropus was the earliest hominid, dating 7-6 million years ago. Orrorin lived about 6 million years ago, while Ardipithecus remains have been dated to 5.8-4.4 million years ago, and the genus Australopithecus. Commonly called australopithecines, they had evolved in East Africa by 4.2 million years ago and were also present in South Africa by three million years ago. -
Fossil records suggest that modern birds originated 60 million years ago, after the end of the Cretaceous period about 65 million years ago when dinosaurs died off. -
Guide fossil: Nummulites.
Geological events: The Alpine orogen developed.
Climate event: Glacial and interglacial periods.
Type of envinroment: Land. -
Angiosperms produce a flower containing male and/or female reproductive structures. Fossil evidence indicates that flowering plants first appeared in the Lower Cretaceous, about 125 million years ago, and were rapidly diversifying by the Middle Cretaceous, about 100 million years ago. -
Big reptiles colonized all environments during the Mesozoic, both terrestrial and aquatic -
Guide fossil: Amonites (Cephalopod)
Geological: The Pangea got broken.
Climate events: Dry climate and low sea level. No glaciations.
Type of envinroment: Land. -
The first major groups of amphibians developed in the Devonian period, from lobe-finned fish which were similar to the modern coelacanth and lungfish. -
These plants originated in the Devonian Period and were widespread by the Carboniferous. In habit, seed ferns resembled some progymnosperms in that they were small trees with fernlike leaves (the equivalent of a progymnospermous flattened branch) bearing seeds. -
The Devonian, part of the Paleozoic era, is otherwise known as the Age of Fishes, as it spawned a remarkable variety of fish.
The diversification of jawed and bony fishes occurred during this period. -
Cambrian explosion, the unparalleled emergence of organisms at the beginning of the Cambrian Period.
It happened more than 500 million years ago. It was when most of the major animal groups started to appear in the fossil record, a time of rapid expansion of different forms of life on Earth -
Guide fossil: Trilobites (artrópodos)
Geological event: Cambrian explosion. Permian extintion.
Climate events: Increase in the heat of the earth.
Type of envinroment: Marine+Land. -
From unicellular and prokaryotic organisms, to pluricellular and eukaryotic organisms. -
(unicellular and prokaryotic) -
Guide fossil: Stomatolitos (cianobacterias)
Geological event: Early evolution of the Earth. First orogens.
Climate event: Glaciations. The oxygen increased.
Type of environment: Marine.