Colours of Wildlife: Copepteryx
Created | Updated Aug 9, 2015
Willem is a wildlife artist based in South Africa. He says "My aim is simply to express the beauty and wonder that is in Nature, and to heighten people's appreciation of plants, animals and the wilderness. Not everything I paint is African! Though I've never been there, I'm also fascinated by Asia and I've done paintings of Asian rhinos and birds as well. I may in future do some of European, Australian and American species too. I'm fascinated by wild things from all over the world! I mainly paint in watercolours. . . but actually many media including 'digital' paintings with the computer!"
Another prehistoric special! Today I have for you a bird called Copepteryx, which is Greek for 'oar wing'. It is an appropriate name: Copepteryx was a flightless bird that nevertheless used its wings to propel itself with underwater. It lived in the ocean waters around Japan and Eastern Asia.
Plotopterids: The Giant Cormorant-Penguins of Old
Copepteryx was a member of the Plotopteridae. This is a family of birds that is now extinct. The plotopterids were relatives of the pelicans, cormorants and gannets that still exist today. Overall, they must have seemed very much like hybrids between cormorants and penguins. They had the small but functional wings, that they could use to swim with, but they also had large, webbed feet – so they could use both sets of limbs for swimming. They had long and flexible necks with which they could dart their heads out to snatch fish in their bills. Their heavy, dense-boned bodies were not very buoyant, and so they could likely dive down to considerable depths. The plotopterids were very large birds. The smallest were around the size of the largest of our present-day cormorants, while the largest, Copepteryx among them, reached 2 m/6'6" in overall length!
Life in the North Pacific
The plotopterids were restricted to the northern parts of the Pacific Ocean. Their fossils have been found in Japan and the states of California and Washington in the USA. Being flightless, they most likely were dependent on islands on which to nest and breed. They would have sought out islands without any large predators present. Fully-grown plotopterids would have been able to defend their chicks against anything smaller than themselves. Luckily, there are many islands off the shores of the northwestern USA and eastern Asia – although back then they lived, the coastlines and islands would have looked quite different from today!
A Mirror-Scene in the South
What is very interesting is that there existed at the same time a group of birds that were extremely similar to the plotopterids, but in the South rather than the North. They were – the penguins! Penguins originated at about the same time as the plotopterids, and the early penguins were indeed very similar to them. So the plotopterids held sway in the north, while the penguins lived off in the cold Antarctic waters. The penguins back then also evolved into giant forms, not quite as long in body as the plotopterids, but some of them were stouter-bodied and heavier.
Death of a Family
The first fossils of plotopterids are known from the Eocene, the second-oldest epoch of the so-called 'Age of Mammals', the Cenozoic. Of course, many other groups flourished in the Cenozoic as well, birds not at all being the least among them. The Eocene was followed by the Oligocene, but the heyday of the plotopterids was the next epoch, the Miocene. The Miocene lasted from 24 to about 5 million years ago. But the plotopterids went extinct before the end of the Miocene. What happened?
Very large, flightless, swimming birds had existed before, an example being the Hesperornithids which already were highly adapted for an oceanic lifestyle in the Cretaceous, when the dinosaurs were still around. By the time the plotopterids turned up, much had changed. The great sea-living reptiles, which lived with the dinosaurs, such as the fish-like ichthyosaurs, the long-necked plesiosaurs and the lizard-like mosasaurs, were all gone. Sea turtles still existed, but they had specialized ecological needs, leaving room for mid-sized to large, fast-swimming hunters. Plotopterids filled this niche. Being birds, they were warm-blooded and could sustain high levels of activity even in the cold northern waters. They could hunt small to medium-sized fish, and retreat to their nesting and roosting islands when not hunting.
But as I've said, the Cenozoic was not without good reason called the Age of Mammals. When the dinosaurs died out, the mammals that were left, were mostly small, forest-living critters. It took them many millions of years to evolve to the point where again there were large living things lumbering around on the land. But the seas were also open to receive them. Several groups made the transition, the foremost being the Cetaceans, the whales and dolphins. The Sirenians, the group that today includes the manatees and the dugongs also became fully aquatic, but they were mainly slow-moving vegetarians. But one group of carnivorous animals, close relatives of bears and dogs, also went back to the seas – the Pinnipeds, which today include the seals, sea-lions and walruses.
All of this took time. Whales evolved from land-living, hoofed mammals. The very first whales were amphibious and could live on land or in the water. In time they became fully aquatic and unable to leave the water. They rapidly diversified into big, medium and small species. The pinnipeds never became as fully aquatic as the whales, but became very proficient at swimming, all the same. They, too, rapidly evolved into species of various sizes, and making use of a variety of marine food sources.
What we suspect happened, is that these new sea-living mammals, most specifically the smaller whales and dolphins, as well as many of the seals and sea-lions, competed with the plotopterids for the same food sources. Somehow they must have been better at the way of life, causing the plotopterids to dwindle and eventually die out.
At the same time in the Antarctic, the dolphins and seals competed with the giant penguins as well! And the same thing happened: the giant penguins all died out. BUT the small and medium penguins survived! There were no seals or dolphins of a similar size exploiting a similar food source – although some dolphins and seals ate the penguins themselves. But it is better to be preyed upon than to face competition for the same food source from a rival that is better equipped. After all, a predator needs its prey to remain around or it will die from starvation! So, many smaller penguins survived the spread of the seals and dolphins, and today the family is still with us.
Unfortunately there were no small plotopterids. Their place was taken by the much smaller auks, a family that also became adapted for wing-propelled underwater swimming, but most members of which retained the power of flight. And so when the big plotopterids died out, the family in its entirety was gone forever.
And so ended the story of these big swimming birds of the northern seas. Today we know them only from the bones they left behind. As with all my prehistoric reconstructions, the colours and details of the plumage are all my own invention. We don't really know exactly what they looked like. We also don't really know exactly what they lived like, although we can get many clues from the nature of their bones and the places where we find them. Still, being extinct, without living examples to study, we are left with a great many questions about them. We still know very little about the living world around us, of which we too are a part. The species that survive today are still mostly riddles to us. Conserving them is vital for us to learn what they are all about. And in the process we learn more about ourselves and our own potential as living members of this profoundly diverse and creative planet.