La Palma giant lizard


The La Palma giant lizard is a giant lacertid historically living on the island of La Palma ; its habitat ranged from sea level up to altitudes of 800 m.
It probably lives in xerophytic vegetation and is presumably an egg-laying species.
Generally considered extinct in historic times, there were sightings of a large lacertid in 2007 which may possibly correspond to this species, although these sightings have been assessed as doubtful.

Taxonomy

Working on fossil and subfossil evidence, this giant lizard was originally described as a subspecies of the El Hierro giant lizard. Later, it was elevated to full species rank. Specimen remains from La Palma assigned to G. goliath seem to belong to this taxon instead; if this is correct, they indicate that the average size of this species had been decreasing over the last millennia, possibly due to humans preferring to hunt larger lizards. The recently sighted La Palma giant lizard individual was slightly more than 30 cm long and had an estimated age of four years. New expeditions to the area of the rediscovery are planned in the hope of finding more individuals and possibly a breeding population.
However, scientists have not had the chance of studying any living specimen and the present fossil and subfossil material of G. auaritae does not allow for sufficiently detailed analyses of its phylogenetic status. Probably it belongs to the simonyi clade like the other giant Gallotia species from the western islands, but whether it actually was as close to G. simonyi as presumed remains unverified. The reason for this is also that it was only discovered after the present species' description that G. goliath was not another local representative of G. simonyi, as was previously assumed, but a more distantly related species.

Status

Its decline may have started 2000 years ago with the arrival of humans on La Palma. Until its recent sightings, it was believed to have become extinct in the last 500 years. The main causes of this presumed extinction were believed to have been introduced cats, consumption by the original human population of the Canary Islands, and habitat destruction for agriculture. It is not the only lizard from the Canary Islands to have been considered extinct only to be rediscovered later: This happened with other giant lizards of the Canary Islands, like the El Hierro giant lizard and La Gomera giant lizard ; the somewhat smaller Tenerife speckled lizard was only discovered for the first time in 1996.
At this point, not a single living individual has been captured and any remaining population, if existing, is assumed to be tiny.