Meet Heracles Inexpectatus: The Giant Prehistoric Parrot That Lived 19 Million Years Ago

Researchers have discovered an extinct species of bird in New Zealand which they say is the heaviest known parrot to have ever lived.

Known as Heracles inexpectatus, the bird may have grown to just over 1 meter (3.3 feet) in height and weighed around 7 kilograms (15 pounds,) according to a study published in the journal Biology Letters.

Its name refers to Heracles—a figure in Greek mythology who is known for his adventures with large mythical beasts—and the unexpected nature of the bird's discovery.

"Heracles, as the largest parrot ever, no doubt with a massive parrot beak that could crack wide open anything it fancied, may well have dined on more than conventional parrot foods, perhaps even other parrots," Mike Archer, from the University of New South Wales (UNSW) Sydney, said in a statement.

The fossils were found at a well-known site in the Central Otago region of New Zealand's South Island in a deposit that dates back to around 19 million years ago—a time when the area would have experienced a subtropical climate.

"This was a very different place with a fauna very unlike that which survived into recent times," Vanesa De Pietri, from the Canterbury Museum, said in the statement.

As well as numerous other species of fossil birds, the area is rich in the remains of ancient crocodiles, turtles, bats, and other animals.

"We have been excavating these fossil deposits for 20 years, and each year reveals new birds and other animals," Trevor Worthy, from Flinders University, said in the statement.

"While Heracles is one of the most spectacular birds we have found, no doubt there are many more unexpected species yet to be discovered in this most interesting deposit," he said.

The researchers say that Heracles likely lived in subtropical forests which were rich in laurels, palms and podocarp trees.

"Undoubtedly, these provided a rich harvest of fruit important in the diet of Heracles and the parrots and pigeons it lived with," Suzanne Hand, also from UNSW Sydney, said in the statement. "But on the forest floor Heracles competed with adzebills and the forerunners of moa."

Heracles belongs to a group of ancient parrots native to New Zealand, which includes the kakapo—a critically endangered flightless bird which still exists in the country. The kakapo is the heaviest parrot alive today although it is about half the weight of Heracles.

Kakapo are nocturnal parrots that live on the ground and are found only in New Zealand. They are critically endangered, with only 144 known individuals remaining, all of which are named.

Like many birds that are native to one island—or a set of islands—the kakapo has a number of unusual characteristics. For example, it is the only flightless parrot and researchers think it may be one of the world's longest-lived birds. In fact, the oldest known kakapo—dubbed "Richard Henry" after a pioneering conservationist—is thought to have died at the grand old age of 80.

It is not unusual for large birds to evolve on islands. Notable examples are the dodo in Mauritius, giant pigeons in Fiji and giant storks in the Indonesian island of Flores.

"New Zealand is well known for its giant birds," Worthy said. "Not only moa, but giant geese and adzebills shared the forest floor, while a giant eagle ruled the skies. "But until now, no-one has ever found an extinct giant parrot—anywhere."

Heracles inexpectatus
Reconstruction of the giant parrot Heracles inexpectatus. Brian Choo, Flinders University