A team of researchers from the Canterbury Museum discovered Crossvallia waiparensis after studying fossils found in Waipara, near the city of Christchurch on New Zealand's south island, according to a press release.
The giant penguin, which stood 1.6 meters (5 feet 3 inches) tall, is the latest member of a growing cast of massive fauna that used to call the island nation home. These include the world's biggest parrot, a giant eagle, a giant burrowing bat, and the moa, a kind of large flightless bird.
At 70-80 kilograms (154-176lb), the penguin would have weighed more than the world's average human being, who tips the scales at 62 kilograms (137lb) according to a 2012 BMC Public Health study.
It lived between 66 and 56 million years ago, during the Paleocene Epoch, making it one of the world's oldest known penguin species.
The largest living penguin species is the Emperor Penguin, which stands 1.2 meters tall.
Amateur paleontologist Leigh Love discovered the giant penguin bones in 2018, and they were analyzed by a team from the Canterbury Museum and the Senckenberg Natural History Museum in Frankfurt, Germany.
According to researchers, the giant penguin's closest relative is another Paleocene species, Crossvallia unienwillia, and this second discovery provides further evidence that early penguins were massive.
"It further reinforces our theory that penguins attained a giant size very early in their evolution," said Vanesa De Pietri of the Canterbury Museum.
The fossilized remains of Crossvallia unienwillia were found in Antarctica, and researchers say the discovery provides evidence of a close connection between New Zealand and Antarctica.