RESEARCHERS have described two new species of bent toed gecko native to Papua New Guinea, identifying one as potentially the largest of all geckos in the world.

Made by a research team led by Paul Oliver of the Australian National University and the University of Melbourne, the discovery was reported in a paper published by peer-reviewed journal ZooKeys.

The researchers were investigating animals in the Cyrtodactylus novaeguineae complex using molecular and morphological data.

On the basis of this data, the researchers have described two new species due to differences in size, build and colouration.

The larger of the two, Cyrtodactylus rex, can grow up to 17 centimetres in length, with the females larger than the males.

It is also characterised with upper body side covered in alternating regions of darkgrey brown and medium brown – and while they are variable in size and shape, it has clearly defined dark grey-brown markings.

All examined specimens are reported to have either four or five dark brown blotches or bands running down their original tails.

The second new species – Cyrtodactyulus equestris – can measure 14 centimetres for the females – above the 13 centimetre length which is common of bent toed gecko species.

Similarly to its larger relative, its head is large and wide, clearly distinct from the neck, while its upper side is coloured with alternating regions of light and medium brown.

While in smaller individuals the patches are visibly defined by dark brown edging, such is missing in the larger ones, giving their pattern slightly faded appearance.

Early findings suggested that the smaller Cyrtodactyulus equestris is seemingly restricted to hill and lower montane forests in the foothill forests of the North Papuan Mountains, while Cyrtodactyulus rex is more widespread across the surrounding lowlands.

While the larger size of the New Guinean bent-toed geckos seems to be an evolutionary trend, the role of potential factors such as competition, ecological diversification, isolation and dispersal remains quite a mystery.