Jamaican giant galliwasp

Last seen in 1851

The Jamaican giant galliwasp, endemic exclusively to the Caribbean island of Jamaica, belongs to the family of diploglossids (Diploglossidae)—lizards with small but well-developed legs. A report written around 1850 by the English naturalist Philip H. Gosse indicates that the Jamaican giant galliwasp was still commonly found at that time. The reptile was last sighted in 1851 in the Jamaican Hellshire Hills, which is why herpetologists assume that the lizard species is now extinct.

The international conservation organization IUCN lists the Jamaican giant galliwasp as “critically endangered (possibly extinct).” Since the remaining swamp areas in the Black River region of Jamaica are difficult to access, there is hope that the Jamaican giant galliwasp may have survived, even if only in a very small population.

Introduced predators exterminated native species

Since the discovery of Jamaica in 1492, humans have—both intentionally and unintentionally— introduced alien, predatory animal species to the island, above all Javan mongooses (Herpestes javanicus). The intentional introduction of the Javan mongoose in 1872 was actually meant to curb the rat plague. Previously, rats had been unintentionally introduced to Jamaica, causing great damage to the sugarcane plantations.

The small Indian mongooses had no positive effect on the rat plague; instead, they—together with also introduced cats and dogs—led to the extinction of endemic animal species. These included, besides the Jamaican giant galliwasp, the black racer, at least five native bird species (including Gould’s emerald), and one land mammal, the Jamaican rice rat (Oryzomys antillarum).

Jamaican giant galliwasp – fact sheet

alternative names	Jamaica giant galliwasp, sinking galliwasp
scientific names	Celestus occiduus, Lacerta occidua, Scincus gallivasp, Diploglossus shawii, Diploglossus cliftii, Celestes impressus, Diploglossus occidus, Macrogongylus brauni
original range	Jamaica (Caribbean Islands)
time of extinction	after 1851
causes of extinction	animals introduced to the island, habitat loss
IUCN status	critically endangered (possibly extinct)

Historical habitat difficult to access

Gosse reported around 1850 that the Jamaican giant galliwasp was widespread in the 18th century in Bluefields in the swamp area of the Black River. The river once fed the Black River Morass at its estuary. Since then, more intensive search efforts could not take place in the historical range of the lizard species for safety reasons due to extensive cannabis cultivation.

The conversion of forested swamps for timber extraction and the creation of agricultural land and housing has taken place on a large scale in the Black River Morass over the past two centuries. It can be assumed that, besides the introduced mammals, the extensive draining of the moorland was responsible for the disappearance of the Jamaican giant galliwasp.

Jamaican giant galliwasp—the largest of its genus

The Jamaican giant galliwasp was a fairly large lizard species; females reached a body length of about 25.6 centimeters, males of 30.5 centimeters. Gosse described the Jamaican giant galliwasp as the largest species of its genus. Its legs were long compared to other anguimorphs (Anguimorpha).

The coloration of the Jamaican giant galliwasp was described as light brown with darker markings. It is said that the lizard could extend these colors with a yellow, which in turn explains its name.

170-year-old museum specimen returns to Jamaica

As part of reparative measures, the University of Glasgow intends to return a 170-year-old museum specimen of the Jamaican giant galliwasp to Jamaica, as reported by Daily Record in April 2024. The animal was probably collected in the 1850s.

The specimen at the Hunterian Museum of the University of Glasgow became part of the collection in 1888, after ethnographic and zoological specimens were transferred from another collection in Glasgow, the Andersonian Museum. The Jamaican giant galliwasp, an adult specimen, is kept in a jar and preserved in 70% ethanol. It is said to be in good condition for such an old wet specimen.

The lizard is to be deposited at the Natural History Museum of Jamaica as a permanent loan in the national flora and fauna collection, to keep it safe and ensure that it is accessible to all Jamaicans.