Fossils of this lizard have been found in volcanic caves, where they often appear with those of other animals, like the Tenerife giant rat.

Prehistoric Gallotia remains have been assigned to the taxa G. maxima and G. goliath, the former supposedly occurring only on Tenerife, the latter on several islands.

[4] Based on DNA sequence analysis of mummified remains, G. goliath is a valid species that probably was restricted to Tenerife, and apparently was closer to the Tenerife speckled lizard (Gallotia intermedia) than to the El Hierro giant lizard.

Bone remains of this species have been found in different archaeological sites with marks that show that they were consumed by the aborigines of the island (Guanches).

There is written documentation about its existence in the fifteenth century, so its extinction must have occurred in the years after the conquest of the Canaries by the Castilians.