Colours of Wildlife: Pelagornis sandersi: Longest Wings of All
Created | Updated Nov 29, 2015
Pelagornis sandersi: Longest Wings of All
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!"
Again a Prehistoric Special, and a very special one! Pelagornis sandersi ('Sanders' Ocean Bird' – what an unimaginative name!) was the bird that, as far as we know, had the greatest wingspan of all: estimates range from 6.1 to 7.4 m, making its wingspan about twice that of the largest bird that survives at present, the Wandering Albatros. I have here reconstructed Pelagornis imaginatively. We do not really know what it looked like in real life, having only its bones. I took inspiration from living birds like albatrosses and tropicbirds in deciding how to colour it. Pelagornis was actually not closely related to albatrosses; we're not exactly sure which modern species are its closest relatives, but they might be pelicans, storks, or wildfowl.
The False-tooth Birds
You can see this bird's 'teeth' in my reconstruction. They make it look a bit like a pterosaur – which it is not at all! It was a real bird indeed, for all purposes as fully and modern a bird as any that live today. Actually, those are not real teeth! They're 'false teeth' or pseudoteeth … bony projections from the margins of the bill, in life covered by the keratinous sheath or rhamphotheca, which covers the bills of all birds. There are today still a few birds that have similar 'teeth', though ones not quite as spectacular: the mergansers (relatives of duck and geese which I'll feature here soon), most particularly.
Pelagornis had pseudoteeth of different sizes, large ones interspersed with smaller ones. It most likely used these teeth for grabbing fish and other aquatic critters from the water. It might have done this in mid-flight. With its huge wings, and using the wind currents forming over the waves, it might have been able to fly slowly over the ocean, sometimes even able to hover in one place. That would allow it to scan the water and grab what appealed to it.
It also probably would have been able to land on the water. Like living albatrosses, it had fairly short legs, but webbed feet. When the winds were not right for flying, it might then have settled onto the sea and floated and bobbed on the waves and paddled itself about; it might still have hunted like this, while waiting for the winds to return so it could fly again.
Being an ocean bird, and a superlative soarer, Pelagornis was able to go pretty much where it pleased, and its fossils have been found all over the world: North America, South America, Europe, Africa, and perhaps even New Zealand. The genus included other, smaller species. Pelagornis sandersi was one of the oldest species, occurring in the Oligocene, about 25 million years ago. Its fossils were found in North Carolina, in a place that was inundated by the ocean back then. The global climate was warmer then than it is now, and with less ice existing at the poles, the sea level was comparatively higher than it is today. Other species of Pelagornis might have survived up till as recently as 2.5 million years ago.
Pelagornis was not the only known false-toothed bird. Its relatives include Osteodontornis and Odontopteryx. All of them were generally large birds, Osteodontornis coming close to it in size. They all must have lived in a similar manner.
Not quite the largest
Although Pelagornis has the longest known wingspan of any bird, it wasn't the largest flier. Among the birds, that distinction goes to the monster-bird Argentavis magnificens, which I am going to feature here soon! While Argentavis had a wingspan of about 6 m and thus perhaps only a bit less than Pelagornis, it was much more heavily built. Pelagornis is estimated to have had a bodyweight of between 22 and 40 kg/about 50 to 90 lbs, but Argentavis reached a weight of perhaps as much as 80 kg/175 lbs. Argentavis had wings that were much broader, while Pelagornis had extremely long and narrow wings.
But not even Argentavis was the largest flying creature ever. Back in the days of the dinosaurs, there were the pterosaurs, which were NOT dinosaurs as some people think, but an entirely different group of flying creatures. It's also not really accurate to call them 'flying reptiles' since, like dinosaurs, they were not really very reptilian or closely related to modern reptiles such as lizards or snakes. They were most likely warmblooded, many of them covered in fuzz, energetic and active. They were capable of powered flight. The largest pterosaurs known are the genera Quetzalcoatlus and Hatzegopteryx, both of which had wingspans of up to 10-11 m. What's more, these pterosaurs were huge-bodied, perhaps weighing as much as 250 kg, and with enormous skulls, about 3 m in length! Unfortunately, we still know very little about those giant pterosaurs, how they lived, how they flew, and how they were able to become so big. The heaviest flying creature of our time is the Kori Bustard, which, with a wingspan a bit over 2 m, reaches 18 kg/40 lbs in bodyweight. Aerodynamic calculations can't account for how things like Pelagornis, Argentavis or Quetzalcoatlus were able to fly at all! (Even though today, in spite of a widely believed myth, we do understand how a bumblebee can do it.)
I generally end my articles with a note of the existence status of the species I treat. In this case, sadly, Pelagornis has the status of 'extinct'. Not only it, but all of the false-tooth and bone-toothed birds are extinct today. It's not clear why they went extinct, but they all went extinct long before humans became the biodiversity-destroying phenomenon that resulted in so many recent extinctions. When they went extinct, about 2.5 million years ago, 'we' were still at the Australopithecus stage, just on the verge of learning to use fire and to make stone tools, and still confined to Africa, and at the mercy of many predators. So we can't be blamed for their extinction. But that time was the start of a period of global climatic instability, that soon led to the Ice Ages of the Pleistocene. Something caused these great ocean birds to go extinct, and today the albatrosses are their ecologic replacements. But it is sad that we can no longer see these immense toothy-billed birds soaring over our oceans.
