New Zealand's ancient monster penguins had northern hemisphere
doppelgangers

Date:
June 30, 2020
Source:
Canterbury Museum
Summary:
New Zealand's monster penguins that lived 62 million years ago had
doppelgangers in Japan, the USA and Canada, a new study has found.



FULL STORY ==========================================================================
New Zealand's monster penguins that lived 62 million years ago had doppelgangers in Japan, the USA and Canada, a study published today in
the Journal of Zoological Systematics and Evolutionary Research has found.


========================================================================== Scientists have identified striking similarities between the penguins' fossilised bones and those of a group of much younger Northern Hemisphere birds, the plotopterids.

These similarities suggest plotopterids and ancient penguins looked very similar and might help scientists understand how birds started using
their wings to swim instead of fly.

Around 62 million years ago, the earliest known penguins swam
in tropical seas that almost submerged the land that is now New
Zealand. Palaeontologists have found the fossilised bones of these
ancient waddlers at Waipara, North Canterbury. They have identified
nine different species, ranging in size from small penguins, the size
of today's Yellow-Eyed Penguin, to 1.6 metre-high monsters.

Plotopterids developed in the Northern Hemisphere much later than
penguins, with the first species appearing between 37 and 34 million years
ago. Their fossils have been found at a number of sites in North America
and Japan. Like penguins, they used their flipper-like wings to swim
through the sea. Unlike penguins, which have survived into the modern era,
the last plotopterid species became extinct around 25 million years ago.

The scientists -- Dr Gerald Mayr of the Senckenberg Research Institute
and Natural History Museum, Frankfurt; James Goedert of the Burke Museum
of Natural History and Culture and University of Washington, USA; and Canterbury Museum Curators Dr Paul Scofield and Dr Vanesa De Pietri --
compared the fossilised bones of plotopterids with fossil specimens of
the giant penguin species Waimanu, Muriwaimanu and Sequiwaimanu from
Canterbury Museum's collection.



==========================================================================
They found plotopterids and the ancient penguins had similar long beaks
with slit-like nostrils, similar chest and shoulder bones, and similar
wings. These similarities suggest both groups of birds were strong
swimmers that used their wings to propel them deep underwater in search
of food.

Some species of both groups could grow to huge sizes. The largest known plotopterids were over 2 metres long, while some of the giant penguins
were up to 1.6 metres tall.

Despite sharing a number of physical features with penguins both ancient
and modern, plotopterids are more closely related to boobies, gannets
and cormorants than they are 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 large plotopterid species would have looked very similar to the ancient
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 in the evolution of the bird groups hint at an explanation for why birds developed the ability 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 giant penguins, including Waimanu
and Sequiwaimanu are currently on display alongside life-sized models
of the birds in Canterbury Museum's exhibition Ancient New Zealand:
Squawkzilla and the Giants, extended until 16 August 2020.

This research was partly supported by the Royal Society of New Zealand's Marsden Fund.


========================================================================== Story Source: Materials provided by Canterbury_Museum. Note: Content
may be edited for style and length.


========================================================================== Journal Reference:
1. Gerald Mayr, James L. Goedert, Vanesa L. De Pietri, R. Paul
Scofield.

Comparative osteology of the penguin‐like mid‐Cenozoic
Plotopteridae and the earliest true fossil penguins, with comments
on the origins of wing‐propelled diving. Journal of Zoological
Systematics and Evolutionary Research, 2020; DOI: 10.1111/jzs.12400 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/06/200630155747.htm

--- up 23 weeks, 2 hours, 39 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1337:3/111)