Millions of years ago, the world was crawling with “mega penguins” like the Palaeeudyptes klekowskii, which stood nearly seven feet tall, and the Kumimanu fordycei, which weighed some 350 pounds — but why did they go extinct?
Nature Picture Library / Alamy Stock PhotoAn illustration of the extinct mega penguin Palaeeudyptes klekowskii (right) with a human and Emperor penguin Aptenodytes forsteri (center) for scale.
In prehistoric times, the Earth was crawling with several giant versions of the animals we know today, including sloths the size of elephants, 50-foot-long snakes, and armadillos the size of cars. Researchers have theorized that these megafauna species evolved to be large in order to better capture prey, defend themselves against predators, access hard-to-reach food sources, or regulate their body temperatures. And penguins were no exception.
In 1990, scientists in Antarctica discovered a mega penguin species called the Palaeeudyptes klekowskii. Before it went extinct some 37 million years ago, this colossus penguin stood nearly seven feet tall — towering over many famous basketball players.
For years, Palaeeudyptes klekowskii held the record for the largest penguin species in history. Then, in 2017, researchers in New Zealand discovered yet another mega penguin species called the Kumimanu fordycei which weighed nearly 100 pounds more than the Palaeeudyptes klekowskii.
While there’s some debate as to which species was the biggest, in 2023, Guinness World Records recognized the Kumimanu fordycei as the largest penguin to ever waddle the Earth. But whichever species was larger, one thing is certain: These mega penguins offer fascinating insights into our planet’s prehistoric past.
Discovering The Palaeeudyptes Klekowskii
Google MapsSeymour Island, the location of the first Palaeeudyptes klekowskii discovery.
Between 1901 and 1903, the Swedish South Polar Expedition discovered the first penguin fossils on Seymour Island, one of 16 islands near the tip of Graham Land on the Antarctic Peninsula. Since then, more researchers have flocked to the island to study prehistoric penguin species.
In 1990, a team of researchers discovered the fossils of Palaeeudyptes klekowskii on the island. This mega penguin species was previously unknown — and it wasn’t until several new bones were identified in 2014 that scientists realized just how big this mega penguin really was.
Piotr Jadwiszczak / University of Bialystok
Patella and tibiotarsus bones from Palaeeudyptes klekowskii.
The bones revealed that the Palaeeudyptes klekowskii stood at roughly 6’8″ and weighed about 250 pounds when it roamed Antarctica 37 to 40 million years ago, making it the largest penguin species known to history at the time.
The Life Of A Palaeeudyptes Klekowskii In The Eocene
The Palaeeudyptes klekowskii lived in modern-day Antarctica during the Eocene, a period 56 to 33.9 million years ago when carbon levels were remarkably high. Not only had dinosaurs gone extinct by this time, but climates across the globe were warm, humid, and relatively steady, allowing prehistoric animal species to thrive.
Various penguin species appear in Antarctica’s fossil record during this time, including the impressive Palaeeudyptes klekowskii. Back then, about 40 million years ago, the region’s climate was similar to that of present-day Tierra del Fuego, the archipelago at the southern tip of South America.
This was “a wonderful time for penguins, when 10 to 14 species lived together along the Antarctic coast,” Carolina Acosta Hospitaleche, a researcher from La Plata Museum in Argentina, told New Scientist in 2014. According to a 2002 study, climate cooling and other environmental changes gradually led to the diversity among penguin species in this area.
The Palaeeudyptes klekowskii’s impressive size allowed it to hunt larger prey, conserve its body temperature in cold water, and dive deeper and stay underwater longer than its modern counterparts. In fact, Hospitaleche estimates that this mega penguin species could stay underwater for up to 40 minutes, giving it an evolutionary advantage that enabled it to thrive until its extinction.
Other Mega Penguins Impress The Scientific Community
Simone Giovanardi / Bruce MuseumAn artistic rendition of Kumimanu fordycei on a New Zealand beach with the Petradyptes stonehousei, another prehistoric penguin species.
The Palaeeudyptes klekowskii wasn’t the only mega penguin species to shock the scientific world in recent years.
In 2017, a team of researchers led by Alan Tennyson from Museum of New Zealand Te Papa Tongarewa were excavating boulders on a beach of New Zealand’s South Island when they unearthed the fossils of Kumimanu fordycei.
This mega penguin species lived near modern-day New Zealand around 57 million years ago, near the end of the Paleocene epoch.
“New Zealand is (and has been) a great place to be a penguin,” Daniel Ksepka, a paleontologist and curator at the Bruce Museum in Connecticut, told Live Science in 2023. “There are good feeding grounds offshore for marine birds, and there were no land mammals other than bats in New Zealand before humans arrived, which makes for safer nesting areas.”
The Kumimanu fordycei weighed about 350 pounds — more than basketball player Shaquille O’Neal at the peak of his career. On Feb. 8, 2023, Guinness World Records recognized the Kumimanu fordycei as the largest penguin to ever exist.
However, incomplete fossils have made it difficult to pinpoint exactly how tall this prehistoric penguin species stood, leaving some debate as to whether it really was bigger than the Palaeeudyptes klekowskii. Researchers estimate that it stood anywhere between five and six feet, making it shorter than the largest known Palaeeudyptes klekowskii specimen despite being an estimated 100 pounds heavier.
Bruce MuseumCurator Daniel Ksepka standing next to a life-size cutout of the Kumimanu fordycei.
Like the Palaeeudyptes klekowskii, the Kumimanu fordycei would have been an excellent underwater hunter and thrived alongside several other penguin species until it went extinct millions of years ago.
It’s not exactly clear why these mega penguins died out. However, experts have theorized that they went extinct when predatory marine mammals began ruling the seas and either started hunting the penguins or competing with them for food and resources.
After reading about the mega penguins, dive into the story of the megalodon, the largest shark ever to exist. Then, learn about 10 prehistoric creatures that were as terrifying as dinosaurs.
