Carboniferous

The Carboniferous, meaning "coal-bearing", was a period of Earth history spanning from 359 to 299 million BC.

It was during the Carboniferous period that the great coal beds of the planet were laid down. Coal was made from the compressed remains of the vast forests that dominated the supercontinent of Pangaea. The huge forests boosted the oxygen content of the atmosphere, allowing larger animals to thrive. Insects and arthropods grew to tremendous sizes, as did the descendants of the lobe-finned fish, which evolved into four-legged amphibians like Hylonomus and Archaothyris. (PROSE: Prehistory Repeating Itself ^[+]Loading...["Prehistory Repeating Itself (feature)"])

When a Fire-God entered the Doctor's TARDIS, it persuaded the TARDIS to go back in time to the "dawn of Earth" to experience the "pure elemental powers of creation". The TARDIS sank in the mud but returned to Wells Wood in response to built-in safety features. Observing the corals of the limestone, the Fifth Doctor dated the limestone to the Carboniferous Period, or around 500,000,000 BC. The impression of the TARDIS in the limestone was unearthed by quarry workers in the 1980s. (COMIC: The Stockbridge Horror ^[+]Loading...["The Stockbridge Horror (comic story)"])

According to one account, the Silurians first emerged on Earth around 350 million BC, when the planet was "a world of carboniferous tropical jungles and swamps". (PROSE: The Monster Vault ^[+]Loading...["The Monster Vault (novel)"])

The Seventh Doctor observed Carboniferous limestone in France in 1242. (PROSE: Sanctuary ^[+]Loading...["Sanctuary (novel)"])

Behind the scenes

In actuality, the Carboniferous was 298,900,000 to 358,900,000 years ago. 500,000,000 years ago was the Cambrian era.