By Neil Bowdler
BBC science reporter
A giant penguin that preferred the tropics to the southern oceans has been discovered by a team of scientists.
The fossilised remains of the animal, which lived some 36 million years ago, were found in what is today Peru.
At 1.5m (5ft) tall, the penguin looked quite different from its modern-day cousins, a report in PNAS journal says.
It had a long protracted skull and what its discoverers are describing as a grossly elongated beak that was spear-like in appearance.
The Icadyptes salasi penguin would dwarf all the penguins who walk the planet today.
It would have stood head and shoulders over the emperor and the king penguins of the southern seas.
Its well-preserved skeleton was discovered in the Department of Ica on the southern coast of Peru along with the remains of as many as four other previously undiscovered penguin species, all of which appear to have preferred the tropics for colder climes.
Indeed, the Icadyptes appears to have lived happily at such warmer latitudes at a time when world temperatures were much hotter than they are today - and long before anyone thought penguins had reached such low latitudes.
Of course, not all modern-day penguins are adapted for life in cold temperatures.
The African or Galapagos penguins, for example, as their names suggest, also prefer warmer waters to the better-known penguins of the southern seas and Antarctica; but they are comparative newcomers, say the researchers, compared with the giant whose discovery they are now announcing.
"That was sort of a dominant hypothesis - that in fact penguins had only reached low latitude regions comparatively recently and after two major periods of cooling in Earth's history," said Dr Julia Clarke, of North Carolina State University, US, and a member of the research team.
"One was around the Eocene-Oligocene about 34 million years ago; and more recently, post 15 million years ago - but in fact we find penguins there now in much warmer periods and much, much earlier."
Full details are reported in a paper published in Proceedings of the National Academy of Sciences (PNAS) of the United States of America.
Icadyptes salasi had a spear-like beak (top). Scale bar = 1cm
It was much longer and more pointed than the skull of the modern-day Peruvian (Humboldt) penguin Spheniscus humboldti (below)