Ancient Lizard Missing Front Limbs - Yahoo! News
Ancient Lizard Missing Front Limbs - Yahoo! News
Remains from a 95-million-year-old marine creature with nubs for legs is clarifying how some lizards shed their limbs as they crept through evolutionary time and morphed into slinky snakes.
Described in the current issue of the Journal of Vertebrate Paleontology, the snake-like lizard had a small head and willowy body. Extending 10 to 12 inches from snout to tail, the aquatic creature also sported a lengthy neck and relatively large rear limbs. Missing were all the bones of its forearms, including the hands and digits found in modern lizards.
The oddball creature, Adriosaurus microbrachis, is a member of a lineage of lizards thought to be snakes’ closest relatives.
“It adds to the picture we have of what was happening 100 million years ago,” said lead researcher Michael Caldwell, a paleontologist at the University of Alberta, in Canada. “We now know that losing limbs isn’t a new thing and that lizards were doing it much earlier than we originally thought.”
The new fossil reveals the earliest record of this limb-shedding in a lizard and gives scientists a rare glimpse back to the time when terrestrial lizards evolved to be limbless and returned to their watery origins. In fact, the ancestors of all animals lived in aquatic and marine environments.
