Jurassic

The Jurassic was a period of Earth history in which the dinosaurs thrived.

Fauna
The red leeches, known as Crimson Horror, were a species that were supposed to live in the Jurassic era. The Eleventh Doctor expressed intention to return a specimen who was infesting Sweetville in 1893 to the Jurassic era. (TV: The Crimson Horror)

The Brontosaurus was native to the Jurassic period, (TV: Time-Flight) as were the Allosaurus, Pterodactyl, Stegosaurus, (AUDIO: The Monstrous Menagerie) and Tyrannosaurus rex. (PROSE: Made of Steel, COMIC: Invasion of the Mindmorphs)

Megalosaurus and Diplodocus were two dinosaurs that went extinct in the Jurassic due to environmental changes. (PROSE: The Last Dodo)

Timeline
In circa 150,000,000 BC, 63rd century time travellers, including Roger Baskerville and Laura Lyons, arrived to collect Jurassic flora and fauna samples. On the return trip, Baskerville had sabotaged the time machine, leading to the deaths of all party members but himself and Laura, and connecting the Jurassic with 1894 London. Several dinosaurs travelled to that year from there, while Jago, Litefoot, and Arthur Conan Doyle accidentally travelled to in the opposite direction, and encountered Baskerville. After capturing them, and setting his hounds on them, Baskerville was taken down by an individual from the 63rd century, who had discovered their predicament through a message eventually left in the novel The Hound of the Baskervilles by Conan Doyle. (AUDIO: The Monstrous Menagerie)

A Concorde designated Golf Victor Foxtrot mysteriously disappeared from Heathrow Airport in 1982, inadvertently travelling down a time corridor to the Jurassic period. The Fifth Doctor used a second Concorde, designation Golf Alpha Charlie, to investigate the first Concorde's disappearance and followed it back 140,000,000 years through the time corridor. At one point the Master's TARDIS was temporarily disguised as Concorde Golf Victor Foxtrot, and materialised around it. Eventually, Concorde Golf Alpha Charlie was repaired using parts taken from Concorde Golf Victor Foxtrot and returned to 1982, leaving Concorde Golf Victor Foxtrot buried in the past. By 1982 Concorde Golf Victor Foxtrot was fossilised and buried beneath Heathrow. (TV: Time-Flight)

The end of the Cretaceous Period was 50 million years after the upper Jurassic. (PROSE: Blood Heat)

Undated events
According to the Fourth Doctor and his geologic evaluations, the hand of the Kastrian Eldrad landed on Earth during this age. (TV: The Hand of Fear)

Professor Saurian tried to change Earth history using a "roll-back machine" that saw Times Square in New York being evacuated as the city was overrun by dinosaurs from the Jurassic. The Eleventh Doctor defeated Saurian this time by resetting his machine via "reversing the polarity of the neutron flow". Saurian was taken along with his machine and the dinosaurs back to the Jurassic Age. (COMIC: Dinosaurs in New York!)

The Tenth Doctor once visited the Jurassic with new companion Martha Jones, escaping an attack from a Tyrannosaurus rex just in time. Pressured by Cybermen survivors of the Battle of Canary Wharf to reopen the Void in 2008, the Doctor instead opened a space-time portal to the Jurassic at the exact place and time that the TARDIS had departed. The lunging T-Rex came through the portal where it attacked and destroyed two of Cyberman, dragging the remains of one back through the portal to its home time. The Doctor noted how it would drop the Cyberman remains around the Jurassic period. (PROSE: Made of Steel)

The Twelfth Doctor once visited the Jurassic Era with Val Kent and Sonny Robinson. The trip came to a fast end when they were chased back to the TARDIS by a Tyrannosaurus rex who tried to eat them. (COMIC: Invasion of the Mindmorphs)

The Doctor once went on a trip to the Late Jurassic where he encountered Pterodactylus antiquus. (PROSE: Something Borrowed)

Other references
When the Seventh Doctor and Ace encountered dinosaurs — such as Seismosaurus — after landing on Earth, the Doctor believed they had landed in the upper Jurassic, but had actually arrived in an alternate timeline where Silurians ruled over humanity. (PROSE: Blood Heat)

After defeating the red leech known as Mr. Sweet, the Eleventh Doctor suggested returning him to the Jurassic era as a possible solution for what to do with the creature. However, he was instead killed by an enraged Ada Gillyflower. (TV: The Crimson Horror)

The Sontaran Strax defined "Jurassic emergency" the incongruous appearance of a Tyrannosaurus rex in London, during the Victorian era. (TV: Deep Breath)

Majenta Pryce offered Tony to see the Jurassic era if he were to stay at Hotel Historia. (COMIC: Hotel Historia)

Jurassic era orchids grew in the Inner World of Tyler's Folly. (PROSE: Down)

When Ace was trying to persuade the Doctor to take her to prehistoric Earth, she imagined going back to the late Jurassic. (PROSE: Prime Time)

Behind the scene
PROSE: Made of Steel and COMIC: Invasion of the Mindmorphs indicate that the Tyrannosaurus rex was native to the Jurassic period. In the real world, it was native to the late Cretaceous.

The Fifth Doctor says around 140,000,000 years is definitely in the Jurassic in TV: Time-Flight. In the real world, it was in the early Cretaceous, with the Jurassic spanning from about 200 to 145 million years ago.