Silurian

The Silurians, later known as Earth Reptiles were Earth's first known sentient species. Technological advanced, they lived during prehistoric times.

Physical Appearance


Silurians are a very diverse species, with at least two known phenotypes. In general, Silurians are roughly the size of humans, with a large head, four digits on each hand and green scaly skin. Their mouths are small and somewhat sucker-like. The noticeable features of the Silurians are their three eyes. Their main eyes are bright yellow with cat-like pupils. The third eye is red and on their foreheads. They can use this third eyes for a variety of purposes. The Silurians from their first appearance used them for stunning or killing their opponents, signaling each other, or opening Silurian made doors. (DW: Doctor Who and the Silurians) The Silurians from 2084, on the other hand, had eyes that merely glowed whenever they spoke. (DW: Warriors of the Deep) The Silurians seen in their first encounter had green, lumpy skin, a large mouth, rectangular ears and an inset third eye. They were active creatures who spoke quickly in a deeper voice. (DW: Doctor Who and the Silurians) The Silurians seen in 2084, on the other hand, had a stockier build, brown skin, a smaller mouth and the third eye on top. They also had ornate spikes on their head and wore thick armour. They were also slower and spoke in a higher pitched voice. (DW: Warriors of the Deep)

The Sea Devils are also closely related to Silurians, though far enough apart genetically to create problems for the offspring. (MA: The Scales of Injustice)

Technology
The Silurians aren’t much more advanced then the Humans of the 1900s, though they still had many advancements unknown to the Humans. They have simple cryogenic technology, though it had a faulty timer and relied on nearby energy sources. Though they could use their genetic technology to create such creatures as the Myrka, they were still having problems with Silurian/Sea Devil hybrids’ deficiencies. They had some holographic technology as well. The Silurians processed their own food and didn’t rely on harvesting animals or plants. (MA: The Scales of Injustice)

Though the Sea Devils used sonic weaponry, the Silurians relied on the Sea Devils and their third eye for defensive purposes. As such, the Silurians tended not to use weaponry, though they used a Battlecruiser for transportation and offensive purposes. (DW: Warriors of the Deep)



History
At some point in Earth’s history, the Silurians were the rulers of the planet. They were led by the Triad and used the Sea Devils as soldiers. Eventually, they discovered a large planet coming dangerously close to Earth. This panicked the Silurians, who sent themselves into hibernation to protect their species. Though this planet was actually just the Moon, the hibernation technology was faulty. After millions of years, some, but not all of the shelters have been awakened. (DW: Doctor Who and the Silurians)

Re-awakenings
Charles Darwin and the HMS Beagle expedition, along with the Doctor and Evelyn Smith encountered a rogue Silurian group in the Galápagos Islands. It was revealed that the leader of this group had been responsible for creating humanity's prehistoric ancestors via a forbidden breeding program. (BFA: Bloodtide)

In the late 20th century a group of Silurians were awakened from hibernation by the energy from the nearby nuclear power research centre at Wenley Moor. After disagreement between Okdel K'to and Morka over this course of action, Morka won out and the Silurians then attempted reclaim the planet from Humanity by releasing a deadly virus. This plan was stopped by UNIT and the Doctor. Despite the Doctor's best efforts to broker a peaceful solution, the Silurian base was bombed by UNIT on Brigadier Lethbridge-Stewart's order. (DW: Doctor Who and the Silurians)



Shortly afterwards, a different base of Silurians was found. They too wanted to take back Earth, and there was also a schism of power leading to the eventual second invasion. (MA: The Scales of Injustice)

A number of decades later, General Sir Lethbridge-Stewart, the Silurians attempted to finally make peace in the humans, though the general public believed it to be a stunt involving men in rubber suits. (UNIT: The Coup). Later, the Silurians aided UNIT in finding a cure for a deadly plague. (UNIT: The Wasting)


 * How this peace eventually breaks down into the open hostility some eighty years later at Seabase 4 is not known.

Circa 2084, a group of Silurians allied themselves with the Sea Devils, invaded Seabase 4 in another atttempt to provoke war between two human geopolitical power blocs. The Silurians also used a living weapon, the Myrka. (DW: Warriors of the Deep)

Acceptance by humanity
Silurians have also made many minor appearances, as they have been accepted into Terran society by Bernice Summerfield's time, by which time they had spaceflight capacity., when the term "Earth Reptile" was apparently popularized among the Humans. (NA: Love and War).

Alternative histories
In one alternative version of the 1990s, the Doctor having died during the Wenley Moor incident, in his third incarnation. the Silurians rule Earth unchecked, introducing dinosaurs into Earth's ecosystem. (NA: Blood Heat)

In another alternative 1990s, the Doctor died during the same incident. Silurians, Sea Devils and Humans live, however in peace, under the URIC or United Races Intelligence Command, formerly known as UNIT. (DWM: Deadly Genesis)

Other information

 * The Silurians have never been accurately dated. As implied by their names, they were first said to be from the Silurian period (roughly 440 million to 415 million years ago), though this was before the first reptiles had evolved. The Third Doctor stated they were from the Eocene period (roughly 55 million to 35 million years ago), but this was after the extinction of the dinosaurs (which the Silurians were shown using). The Silurians were also seen using a map of Pangea from around 200 million years ago. The PDA The Quantum Archangel suggests that the Moon was orbiting the Earth before 150 million BCE, which means the Silurians ruled before then.
 * One account shows portrays Cybermen on Mondas discovering Silurians and Sea Devils during an unspecified time in the past. Whether these Earth Reptiles evolved on Mondas or were transported there is not clear. The strip also portrays Golgoth, a primordial god-figure, who resembles a Sea Devil and may have some link to the Silurians. (DWM: The Cybermen: The Dead Heart).