A paper to appear on Biology Letters shows the results relating to the analysis of two-legged fossilized bird found near Saint Bathans, a region of Otago, New Zealand.
The latter belonged to a species of parrot today extinct that could be considered as the largest parrot ever known, with double dimensions of the largest parrot currently existing. The new species was named Eracle inexpectatus and the same scientific name underlines how unexpected the discovery was.
The fossil remains were found near a river in the southern part of New Zealand. These are not complete remains but from what they have been able to analyze the researchers have understood that it was a bird belonging to the order of the Psittaciformes, that is the order that includes all the present species of parrots.
The remains belonged to an animal that lived about 20 million years ago, a parrot that weighed about 5 pounds and was unable to fly. Currently, the largest parrot in existence is the kakapo (Strigops habroptila), which is roughly half the size of the Eracle inexpectatus.
This is an example of insular gigantism, a phenomenon of evolution in which certain animal species living in circumscribed environments such as those of the islands increasingly increase the size of their bodies, usually due to a lack of predators.
It is the first example, according to the researchers themselves, of a psittaciform that shows insular gigantism in the course of its evolution.