60 Million Years Ago 'Monster' Penguins the Size of an Average Human Dominated New Zealand’s Seas

Sixty million years ago, a towering creature once loitered through the waters of New Zealand, a ‘monster’ penguin that stood as tall as an average human. This discovery adds to New Zealand’s impressive history of gigantic, now-extinct fauna, which included towering moa birds, huge eagles, burrowing bats, and even an ancient giant parrot known as 'Squawkzilla,' stated Smithsonian magazine.

This gigantic bird, scientifically named Crossvallia waiparensis, was a formidable sight, measuring around 1.6 meters (5 feet 3 inches) in height and weighing up to 80 kilograms (176 pounds). The discovery of its fossilized leg bones in North Canterbury has shed new light on an era where penguins, not mammals, ruled the seas. Paul Scofield, senior curator at Canterbury Museum shared, "This is one of the largest penguin species ever found…Then, for 30 million years, it was the time of the giant penguins…This site is pretty much unique...It's a river bed cutting into a cliff," according to BBC. The reign of these huge penguins came shortly after the Cretaceous period when dinosaurs and large marine reptiles had vanished.

This event of extinction cleared the way for penguins to evolve to massive sizes, dominating the Southern Hemisphere’s waters for nearly 30 million years. Unlike their modern relatives, Crossvallia waiparensis likely relied more on its powerful feet for swimming rather than just its flippers. This anatomical distinction indicates how these early penguins adapted to their warm predator-free environment. Scofield shared, "We think that at the time, animals were evolving very rapidly…Water temperatures around New Zealand were ideal back then, around 25C (77F) compared to the 8C we have now," stated BBC.

Back then New Zealand was still connected to Australia, and, both were linked to Antarctica. This geographical connection explains why the newly discovered species bears a shocking resemblance to Crossvallia unienwillia, a prehistoric giant penguin found in Antarctica. The similarities indicate that New Zealand and the Antarctic once shared not only climate but also wildlife. Scofield explained, "When the Crossvallia species were alive, New Zealand and Antarctica were very different from today—Antarctica was covered in forest and both had much warmer climates." Despite their dominance, the reign of giant penguins eventually came to an end. Theories suggest that the emergence of marine mammals—such as toothed whales and seals—led to the extinction, stated The Guardian.

Another researcher, Gerald Mayr shared, "At the time giant penguins evolved, the large marine reptiles just had become extinct. In Antarctica and New Zealand, there were no large marine competitors until the arrival of toothed whales and pinnipeds (seals) many million years later." The Waipara Greensand site, where Crossvallia waiparensis was unearthed, continues to be a treasure trove for paleontologists. Leigh Love, the amateur fossil hunter who discovered the leg bones, has contributed to one of the most significant findings in avian paleontology. The study authors noted, "[T]he extinction of very large-sized penguins was probably due to competition with marine mammals," stated Smithsonian magazine.