Middle Silurian

Middle Silurians were a Silurian subspecies identified by historians who had been allowed access to the "Monster Vaults" of the databanks in the Doctor's TARDIS. (PROSE: )

Biology
Following the early subspecies, the Silurians adapted to a more desert-like environment, gaining a large carapace like a tortoise shell. Their colouring became lighter and more like sand. Their claws were now hands with opposable thumbs. Most significantly, the Silurians' third eye was now used solely for communication; as individual Silurians were now virtually identical, they used it to indicate who was speaking. As their society had become more technology-based, developing computer manipulators and powerful cutting devices, their telekinetic abilities had atrophied through lack of use. (PROSE: )

History
Circa 2084, a group of Middle Silurians allied themselves with the Sea Devils to invade Sea Base 4. They attempted to launch nuclear weapons to provoke a war between the two major power blocs. They were killed when the Fifth Doctor, perceiving no more peaceful option, flooded the base with hexachromite gas in order to kill them. (TV: )

Behind the scenes

 * Dapol released action figures for both classic series variants of the Silurians, with the Warriors of the Deep variant being distinguished by the name "Armoured Silurian".
 * A figurine of a Silurian from Warriors of the Deep was released in issue 125 of Doctor Who: Figurine Collection under the name "Sea Base Four Silurian".