Monster penguins that roamed New Zealand 62 million years ago had dopplegangers thousands of miles away in the northern hemisphere.
Paleontologists have long known about the hefty penguins of ancient New Zealand, which fossilised bones found in North Canterbury suggest stood at 1.5metres tall and weighed 80 kilograms.
Now evidence of a group of birds which lived in modern day USA, Canada and Japan have also been uncovered.
The plotopterids had a striking resemblance in bone structure to the monster penguins, despite not actually being part of the same species.
Just like penguins the plotopterids used their wings to swim instead of fly and had long beaks with slit-like nostrils.
Unlike penguins, the species became extinct 25 million years ago, having first appeared around 12 million years before that.
A fully grown adult plotopterid could grow up to 2m long in exceptional circumstances - a full half a metre bigger than the biggest giant penguin.
While they may have similarities, the extinct species was more closely related to gannets and cormorants.
Evidence of the plotopterids was written about in the Journal of Zoological Systematics and Evolutionary Research this week.
Although they would have been difficult to tell apart from one another from a distance, giant penguins and plotopterids evolved millions of years and thousands of miles apart.
Paul Scofield, a Canterbury Museum curator in New Zealand, said: "These birds evolved in different hemispheres, millions of years apart, but from a distance you would be hard-pressed to tell them apart.
"Plotopterids looked like penguins, they swam like penguins, they probably ate like penguins -- but they weren't penguins."
