A rare skink and a case of mistaken identity

By Patrick Couper, Senior Curator of Reptiles and Amphibians, Queensland Museum

Tryon’s skink (now Karma tryoni) was described in 1918 by Heber Longman at Queensland Museum. Its description was based on two specimens collected by Henry Tryon in the McPherson Range on the Queensland/New South Wales border. However, until recently this species was overlooked because taxonomists regarded it as conspecific (the same species as) with Murray’s Skink (Karma murrayi), which has a similar appearance and also occurs in the McPherson Range.

In 1998, Ross Sadlier from the Australian Museum demonstrated that Tyron’s Skink is a valid species and resurrected it from synonymy with Murray’s Skink. The two skinks are readily distinguished by variations in colour pattern and by differences in their head and body scales. Although both species occur together above 800 meters, Tryon’s Skink is restricted to these higher altitudes while Murray’s Skink is more abundant at lower elevations.

Tryon’s skink remains poorly known and there is little information on its biology. It probably gives birth to live young and is likely to be a generalist arthropod feeder (although frog eggs were found in the gut of one museum specimen). It is active on warm afternoons and can be seen perched on rocks and logs on the forest floor. When disturbed, it seeks shelter beneath these perching sites or within cavities in fallen logs.

Recognising Tryon’s Skink as distinct from Murray’s Skink has profound conservation implications and illustrates the importance of taxonomic studies for assessing biodiversity, defining species distributions and driving land management decisions. Whilst Murray’s Skink has a broad distribution extending from Barrington Tops in NSW to the Conondale Range in South East Queensland, Tryon’s Skink only occurs on the Queensland/New South Wales border, in rainforests of the Lamington Plateau. This species has a tiny, high elevation distribution that is likely to be further reduced by the impacts of climate change.

The holotype of Tryon’s Skink (described as Lygosoma (Hinulia) tryoni) by Heber Longman in 1918. The description appears in Memoirs of the Queensland Museum, volume six.