It’s no tall tale. An Argentinian lizard has set a record when it comes to regeneration: it has regrown six tails following an injury.

Many lizards can regenerate their tails after being injured or shedding them as a defence strategy to escape predators. In response to a threat, tails can be voluntarily detached at a specific fracture plane in vertebrae. Bleeding is quickly shut off, the tail stubs heal rapidly and regeneration begins.

In some cases, the tail breaks but doesn’t detach completely, leading to the regenerated tail having two or even three tips.


But “this is the first case of ‘hexafurcation’ ever reported”, says Nicolás Pelegrin, who has reported the discovery along with Suelem Muniz Leão. Both are at the Institute of Animal Diversity and Ecology (CONICET-UNC) in Córdoba, Argentina.

“It is not difficult to find scientific reports on lizards with two and even three tails, but there is no information available on cases like this,” Pelegrin says.

The young black and white tegu, Salvator merianae, was brought to Pelegrin by environmental police officers because of its injuries. “I was very surprised when I saw it,” Pelegrin says. “This was the first time I saw a lizard with more than three tails.”

The tegu had a severe injury along the tail. The wound, probably from a sharp object, wasn’t deep enough for the tail to detach completely, but it seems to have been deep enough to stimulate several points in the animal’s vertebrae where regeneration occurs.

While the benefits of living through a potentially deadly attack are obvious, the costs of regrowing multiple tails are uncertain. Such tails can probably hamper a lizard’s movement, social signalling and reproduction, says Pelegrin.

Journal reference: Cuadernos de Herpetología

Read more: “The matrix: The secret to superhealing regeneration”

Image credit: Nicolás Pelegrin