World's largest gecko renamed with the help LSU Shreveport professor

Makenzie Boucher, Shreveport Times
·2 min read

A Louisiana State University of Shreveport faculty member helped in naming the world's largest known gecko following research.

According to LSUS, Dr. Stuart Nielsen co-authored a study in which DNA was extracted from a 200-year-old museum specimen of the Hoplodactylus delcourti, which is 50 percent longer than the second largest known gecko species the Rhacodactylus leachianius.

Dr. Stuart Nielsen, LSUS Assistant Professor of Biological Sciences, co-authored a study in which DNA was extracted from a 200-year-old museum specimen gecko, the largest known gecko species in human history. Genetic analysis led to the renaming of this species to Gigarcanum delcourti.
Dr. Stuart Nielsen, LSUS Assistant Professor of Biological Sciences, co-authored a study in which DNA was extracted from a 200-year-old museum specimen gecko, the largest known gecko species in human history. Genetic analysis led to the renaming of this species to Gigarcanum delcourti.

The Museum d’Historie Naturelle de Marseille in France collected this specimen in the mid-1800s, but due to incomplete records researchers were unable to locate when and where this species was collected. Through physical characteristics researchers believed it roughly matched the description of the kawekaweau, a giant lizard in Maori folklore.

But, with the help of DNA analysis the species appears to be more closely related to “diplodactylid” geckos from New Caledonia, a French island territory north of New Zealand and east of Australia and home to the other giant gecko, R. leachianus.

Nielsen said, “This is a mystery that could only be solved with modern advances in DNA extraction and sequencing. The result has completely rewritten the history of the island rule with respect to gigantism within this lizard family."

A size comparison of the extinct giant gecko, Hoplodactylusdelcourti, with the largest living gecko species, Rhacodactylusleachianus.
A size comparison of the extinct giant gecko, Hoplodactylusdelcourti, with the largest living gecko species, Rhacodactylusleachianus.

With this discovery Nielsen’s group renamed the giant gecko with the genus name Gigarcanum, which consists of two Latin words that mean “giant secret or mystery.” The gecko’s new name in scientific communities is Gigarcanum delcourti.

“Lizards in the genus Hoplodactylus are restricted to New Zealand, and the closest lineages to H. delcourti are from New Caledonia,” said Nielsen. “Although we can’t 100 percent say this gecko is not from New Zealand, all of the evidence we have at the moment suggests it is probably not the kawekaweau of Maori folklore and probably lived in New Caledonia. This meant we needed to give it a new genus name reflecting this novel finding.”

This research has been published in the journal of Scientific Reports.

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Makenzie Boucher is a reporter with the Shreveport Times. Contact her at mboucher@gannett.com.

This article originally appeared on Shreveport Times: LSUS professor helps rename the world's largest gecko