Before an asteroid wiped out non-avian dinosaurs some 65.5 million years ago, supersized penguins breathed the same air as Triceratops. Picture: Maxi Jonas

Before an asteroid wiped out non-avian dinos some 65.5 million years ago, supersized penguins breathed the same air as Triceratops and the flesh-ripping Tyrannosaurus.

The new find, unearthed by an amateur fossil hunter near the Waipara River in New Zealand, does not by itself prove penguin-dinosaur cohabitation.

The eight-centimetre bone dates from about 61 million years ago, well after T-Rex and company faded from the scene.

But the existence of another giant penguin fossil, found earlier nearby, is smoking-gun evidence that a shared ancestor lived millions of years earlier.

“The two penguins — from exactly the same locality — are morphologically quite different,” said Gerald Mayr, an ornithologist at Senckenberg Research Institute in Frankfurt, Germany, and lead author of a study unveiling the discovery.

“This suggests that their last common ancestor lived much earlier, in the time of dinosaurs,” he told AFP.

This handout artwork released by the Geology Museum University of Otago shows giant penguins during the age of dinosaurs. Picture: Chris GaskinSource:AFP

This mother-of-all-penguins probably predated its evolutionary descendants by five to 10 million years, which would have put it squarely in the late Cretaceous period when dinosaurs still flourished, he added.

The results were published in the journal The Science of Nature.

Early penguins probably survived the catastrophic asteroid blast and subsequent change in climate because their food sources were more surf than turf.

By contrast, landlocked dinos that didn’t burn up at impact probably starved to death during the decades-long winter that followed, scientists have speculated.

The Waipara giant penguin stood at least 150 centimetres (five feet) tall, just shy of the average height of a female human.

That’s at least a head taller than the Emperor penguin, the largest of the 17 penguin species — all in the southern hemisphere, and most in Antarctica — alive today.

“It was probably a separate species,” said Mayr. But more bones must be found before it can be declared as such, and formally named.

Only one other prehistoric penguin that lived in Antarctica between 45 and 33 million years ago, Anthropornis nordenskjoeldi, was bigger than Waipara.

All the ancient, giant penguins discovered to date already moved with the upright, waddling gait characteristic of today’s species, the study said.