This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: A lizard making a dramatic escape, leaving its tail wriggling behind as it darts to safety, is an image familiar to many. Tail-shedding is one of the most widespread defenses against predators among living lizards, yet tracing the origins of this extraordinary ability has proved to be surprisingly difficult—how can we tell when this escape tactic first arose in lizards?
A new Tel Aviv University study has found answers to this enigma inside a piece of amber just 18 millimeters (0.7 inches) long—the size of a fingertip—discovered in northern Myanmar. Trapped within it is a lizard's tail that detached from its body approximately 99 million years ago. According to the researchers, it represents the best-preserved direct fossil evidence of a voluntarily dropped lizard tail through a defensive mechanism known as autotomy.
The study was led by Dolev Fabrikant, a Ph.D. candidate at Tel Aviv University's New Environmental School, and his supervisor, Dr. Leonidas-Romanos Davranoglou of the university's School of Zoology and Steinhardt Museum of Natural History, in collaboration with researchers from the National and Kapodistrian University of Athens and Israel's Volcani Institute. The findings are published in Palaeontologia Electronica.
The researchers explain that previously studied reptile fossils have offered evidence of tail-shedding through natural fracture planes in tail vertebrae and regenerated tails. Such features suggest an animal could shed its tail, but in the case of fracture planes, they do not always establish that it did so voluntarily. In the new fossil, the end of the detached tail contains the best-preserved telltale features that allowed the team to investigate precisely how the separation occurred.
For years, the significance of the amber went unnoticed. What initially looked like a tiny twig or a fragment of an insect caught Fabrikant's eye as he examined the specimen more closely. "I realized that what seemed to be a twig was covered in tiny scales," he recalls.
"It was a lizard's tail." When Fabrikant told his supervisor, the response was immediate. "I nearly jumped out of my chair," says Davranoglou. "I instantly realized that this tiny fossil could open an extraordinary window into the past, helping us understand the history of one of the most widespread survival strategies among reptiles.
Extract — continue reading at the source.
