New Zealand’s monster penguins that lived 62 million years in the past had doppelgangers in Japan, the USA and Canada, a research printed at present within the Journal of Zoological Systematics and Evolutionary Analysis has discovered.
Scientists have recognized putting similarities between the penguins’ fossilized bones and people of a gaggle of a lot youthful Northern Hemisphere birds, the plotopterids.
These similarities recommend plotopterids and historical penguins appeared very comparable and may assist scientists perceive how birds began utilizing their wings to swim as an alternative of fly.
Round 62 million years in the past, the earliest recognized penguins swam in tropical seas that just about submerged the land that’s now New Zealand. Paleontologists have discovered the fossilized bones of those historical waddlers at Waipara, North Canterbury. They’ve recognized 9 totally different species, ranging in dimension from small penguins, the scale of at present’s Yellow-Eyed Penguin, to 1.6 meter-high monsters.
Plotopterids developed within the Northern Hemisphere a lot later than penguins, with the primary species showing between 37 and 34 million years in the past. Their fossils have been discovered at plenty of websites in North America and Japan. Like penguins, they used their flipper-like wings to swim by means of the ocean. In contrast to penguins, which have survived into the trendy period, the final plotopterid species turned extinct round 25 million years in the past.
The scientists – Dr. Gerald Mayr of the Senckenberg Analysis Institute and Pure Historical past Museum, Frankfurt; James Goedert of the Burke Museum of Pure Historical past and Tradition and College of Washington, USA; and Canterbury Museum Curators Dr. Paul Scofield and Dr. Vanesa De Pietri – in contrast the fossilized bones of plotopterids with fossil specimens of the large penguin species Waimanu, Muriwaimanu and Sequiwaimanu from Canterbury Museum’s assortment.
They discovered plotopterids and the traditional penguins had comparable lengthy beaks with slit-like nostrils, comparable chest and shoulder bones, and comparable wings. These similarities recommend each teams of birds had been robust swimmers that used their wings to propel them deep underwater searching for meals.
Some species of each teams might develop to very large sizes. The biggest recognized plotopterids had been over 2 meters lengthy, whereas a number of the big penguins had been as much as 1.6 meters tall.
Regardless of sharing plenty of bodily options with penguins each historical and trendy, plotopterids are extra intently associated to boobies, gannets and cormorants than they’re to penguins.
“What’s remarkable about all this is that plotopterids and ancient penguins evolved these shared features independently,” says Dr. De Pietri. “This is an example of what we call convergent evolution, when distantly related organisms develop similar morphological traits under similar environmental conditions.”
Dr. Scofield says some giant plotopterid species would have appeared similar to the traditional penguins. “These birds evolved in different hemispheres, millions of years apart, but from a distance you would be hard-pressed to tell them apart,” he says. “Plotopterids looked like penguins, they swam like penguins, they probably ate like penguins – but they weren’t penguins.”
Dr. Mayr says the parallels within the evolution of the hen teams trace at an evidence for why birds developed the power to swim with their wings.
“Wing-propelled diving is quite rare among birds; most swimming birds use their feet. We think both penguins and plotodopterids had flying ancestors that would plunge from the air into the water in search of food. Over time these ancestor species got better at swimming and worse at flying.”
Fossils from New Zealand’s big penguins, together with Waimanu and Sequiwaimanu are presently on show alongside life-sized fashions of the birds in Canterbury Museum’s exhibition Historical New Zealand: Squawkzilla and the Giants, prolonged till 16 August.
Reference: “Comparative osteology of the penguin-like mid Cenozoic Plotopteridae and the earliest true fossil penguins, with comment on the origins of wing-propelled diving” by Gerald Mayr, James L Goedert, Vanesa De Pietri and R Paul Scofield, 29 June 2020, Journal of Zoological Systematics and Evolutionary Analysis.
This analysis was partly supported by the Royal Society of New Zealand’s Marsden Fund.