Cyber-Silurian

Cyber-Silurian was the name given by the Eleventh Doctor, among the alternatives Cyberlurian, Cybersilon, and Cyber-Reptilia, to a variant of Cybermen that were created through the cyber-conversion of Silurians on prehistoric Earth. They rode cyber-converted dinosaurs and utilised converted Cyber-Arks.

The cybercircuitry used on their dinosaurs was weak to the sonic screwdriver. (COMIC: Supremacy of the Cybermen)

History
When the Cybermen allied with Rassilon to take over history, prehistoric Earth was among the periods they invaded, upgrading Silurians and dinosaurs alike. These converted Silurians were encountered by the Eleventh Doctor and Alice Obiefune, who had visited the period to collect a fruit as a gift for their Silurian friend, Vastra.

Turning against the Cybermen, Rassilon used the regeneration energy he gathered with the Twelfth Doctor to restore the universe, with cyber-conversion the Silurians had undergone being eliminated. Ultimately, the universal regenerative process resulted in the Silurians' conversion never having occurred in the first place. (COMIC: Supremacy of the Cybermen)