Although extinct, C. waiparensis is now one of the world's oldest and largest known penguin species - weighing up to 176 pounds and standing nearly 5'3" – about the average height of an American woman. It is much larger than the Emperor Penguin, the tallest and heaviest of all living penguin species.
"A team comprising Canterbury Museum curators Dr. Paul Scofield and Dr. Vanesa De Pietri, and Dr. Gerald Mayr of Senckenberg Natural History Museum in Frankfurt, Germany, analyzed the bones and concluded they belonged to a previously unknown penguin species," the Canterbury Museum .
Amateur paleontologist Leigh Love discovered the fossils in North Canterbury, New Zealand, in 2018 at the Waipara Greensand fossil site. Local fossil experts helped decipher the discovery, their findings were published this week in Alcheringa: An Australasian Journal of Palaeontology. It was the fifth ancient penguin species discovered in the famous fossil site; many of the discoveries are stumbled upon by amateur paleontologists such as Love.
The closest known relative to "C.waiparensis is a fellow Paleocene species, Crossvallia unienwillia," whose fossils were found in the Cross Valley of Antarctica in 2000. This shows the connection that New Zealand and the icy Antarctic shared millions of years ago, when Antarctica was connected to Australia and New Zealand, until continental drift caused them to part.
“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,” said Scofield. De Pietri added that, "C. waiparensis approaches the size of the Eocene taxa Anthropornis and Palaeeudyptes and provides further evidence that penguins attained a very large size early in their evolutionary history."
The features of both species of extinct penguins were apparently more adapted to swimming rather than standing upright compared to living species of penguins today. Considering the differences in climates, the extinct species would have had a greater need to be more acclimated and reliant on swimming in vast, warm oceans populated by "giant turtles, corals and strange-looking sharks" rather than standing and walking on the natural icy structures of the Antarctic.
There is no clear evidence as to why large species of penguins have for the most part almost completely died out. However, Mayr adds that during the later stages of their existence, the introduction of many large amphibious predators were responsible for their eventual demise.
"At the time giant penguins evolved, the large marine reptiles had just become extinct," which was the reason for the penguins' large growth and size, and lack of competition, Mayr told the BBC. "In Antarctica and New Zealand, there were no large marine competitors until the arrival of toothed whales and pinnipeds [seals] many million years later."
Scofield believes that during this Paleocene Epoch, animals were evolving expeditiously due to ideal water temperatures in New Zealand: 25°C instead of the 8°C waters we have today. He explained further that for 30 million years after the dinosaurs became extinct, "it was the time of the giant penguin."
“The fossils discovered [in the Waipara Greensand] have made our understanding of penguin evolution a whole lot clearer,” Mayr says. “There’s more to come, too – more fossils which we think represent new species are still awaiting description.”
The new findings and fossils will be on display at the Canterbury Museum later this year.