That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information

While working at the Bronx Zoo some years ago, I was delighted to receive a surprise shipment of New Guinea Snake Lizards (Lialis jicari).  Also known as the Long Headed Scaly-foot or Flap-Footed Lizard, it and the related Burton’s Snake Lizard (Lialis bertoni) have long fascinated herpetologists and hobbyists alike.  As you’ll see below, their similarity to snakes goes way beyond a limbless body; indeed, many consider the Snake Lizards to be an example of convergent evolution (unrelated species evolving similar characteristics).  Today I’d like to summarize my experiences and some of what is known about these amazing, little-studied creatures.

Classification

The 2 species mentioned above are the sole members of the genus Lialis. They are classified in the family Pygopodidae, along with approximately 38 other legless relatives. Their distribution is limited to Australia, New Guinea, and some nearby islands.

Snake Lizards have been described by one taxonomist as “legless geckos”, and appear most closely related to that group.  Actually, Snake Lizards do sport remnants of their rear legs, which appear as small skin flaps (hence the name “Flap-Footed Lizard”).  Read More »

Pythons and boas bear small spurs, used by males during courtship, near the cloaca (please see photo).  These vestigial legs provide us with evidence that snakes may once have walked about on 4 limbs, but until recently we could only speculate as to further details.  However, new technology has now enabled us to fill in some of the blanks, and may offer insights into other creatures that seem to be “losing their legs”, such as Worm Lizards and Sirens.

Snake Ancestors

Utilizing a developing technology known as Synchrotron-Radiation Computed Laminography, researchers at the Paris Museum of Natural History were able to microscopically examine snake fossils in new detail.  They concluded that swimming or burrowing lizards were the most likely ancestors of modern-day snakes. Read More »