Traveling to a foreign place is tough under any circumstances. But you can bet your bonnet it was a particularly onerous task 2 million years ago, around the time when early humans first left the African continent.
On these early sojourns, our predecessors didn’t just lack the luxuries of modern wayfarers. Upon entering what’s now Europe, they also had to contend with unpredictable food and water sources, sharp-toothed carnivores… and, apparently, some insanely big birds.
Or, at least, that’s what a new fossil find suggests. According to a study published today in the Journal of Vertebrate Paleontology, early Europe may once have been home to a now-extinct species of giant, flightless bird that clocked in at close to 1,000 pounds, at least three times the weight of your savanna-variety ostrich, the largest bird still alive today.
If the finding pans out, this behemoth bird could occupy a fortuitous juncture in space and time. Not only would it be among the first of its kind documented above the equator—but it may also have had the distinct honor of sharing the landscape with ancient humans at a pivotal point in their geographical diversification.
“If you had asked me before this paper if a giant bird could compete with herbivorous mammals on their own turf in an ice age world, I probably would have said no,” says Bhart-Anjan Bhullar, a vertebrate paleontologist at Yale University who was not involved in the study. “But this is quite a remarkable bird...this study could really add to our understanding of the ancient landscape in which some of our earliest relatives lived.”
It’s only once in a blue moon that evolution cooks up a bird the size of a grand piano. As far as we humans know, it’s happened just a handful of times throughout history, perhaps most famously in the mihirungs (Dromornis) of Australia and the elephant birds (Mullerornis, Vorombe, and Aepyornis) of Madagascar, each of which may have weighed close to 1,500 pounds.
After all, it’s not easy being big. Bulk certainly has its perks, but the downsides range from conspicuousness (a problem for predators and prey alike) to extra exposure to the elements. On the whole, researchers still don’t have a good grasp on all the conditions that precipitated the rise and fall of gigantism in most animal lineages, which makes every new instance a potential paleontological goldmine.
So far, this new specimen is represented by only a single, 15-inch femur unearthed from the Taurida Cave on what’s now the Crimean Peninsula. Without more of the skeleton available, it’s tough to make more than a handful of approximations. But by analyzing the thigh bone’s shape and size, a team led by study author Nikita Zelenkov, a paleontologist at the Russian Academy of Sciences, assigned to the species Pachystruthio dmanisensis—a lineage distinct from the Struthio genus that includes the common ostrich (Struthio camelus).
The name also contains a nod to the nearby archaeological site of Dmanisi, Georgia, where several ancient animal remains (including, Zelenkov notes, a couple giant bird femurs described in 1990 that look strikingly similar to this new one) and some of the oldest known Homo fossils outside of Africa have been uncovered.
Using the bone’s dimensions, the researchers estimated the bird’s body mass to be around half a ton—a quantity nearly on par with an adult polar bear. Through sheer weight alone, P. dmanisensis may be the largest known avian in the northern hemisphere, Zelenkov says.
Based on the fossil’s age—about 1.8 or 1.7 million years old—P. dmanisensis likely kept similarly colossal company. At the time, the creatures that stalked the earth included giant hyenas and supersized versions of today’s carnivorous cats, both of which would have gladly noshed on flightless fowl.
Luckily, it seems this bird had some tricks up its wing. Like many other heavyset avians of the past, P. dmanisensis boasted thick, dense bones that kept it from taking to the skies. But compared to its ancient cousins like elephant birds, this bird had a femur that was relatively slender and long. The bone almost looks like a stockier, more robust version of something you’d find in a modern ostrich—a bird that can sprint at speeds near 45 miles per hour, says Jessie Atterholt, a vertebrate paleontologist and comparative anatomist at the University of California, Berkeley who was not involved in the study.
This similarities hint that P. dmanisensis might have been a pretty capable runner, Zelenkov says.
Of course, with a few hundred extra pounds on its massive frame, P. dmanisensis was almost certainly not dashing about at the same speeds as its distant modern cousin, and probably couldn’t sustain long bouts of continuous movement, says Delphine Angst, a paleobiologist and fossil bird expert at the University of Bristol who was not involved in the study. “It could probably run when it had to,” she says, “but this might not have been [its] favorite way of locomotion.”
But even if the bird was cornered by a particularly dogged carnivore, Bhullar says, it probably had enough heft to hold its own. Though it lacked the ability to fly, he adds, this bird was clearly able to coexist with some of the most formidable foes of the era—including, perhaps, the most dangerous predators of all: early humans.
At least, for a time. P. dmanisensis eventually went the way of the dodo (though if we’re getting technical, it’s really the other way around). What’s not known, however, is why.
Given P. dmanisensis’ placement in time and space, early humans might seem an obvious culprit. (If so, it wouldn’t be the first time a Homo species has driven a big bird to extinction.) But the story might be more complicated than that. Zelenkov thinks there’s a decent chance the birds disappeared without any help from the genus Homo, instead succumbing to a combination of pressures from a changing climate, predation, and disease.
Without more fossils, it’s unclear if these birds interacted much with humans at all, says Julia Clarke, a vertebrate paleontologist at the University of Texas Austin who was not involved in the study. Though the archaeological evidence places the two groups in the same geographic region and date range, more data to suggest they occupied the same sites would strengthen the case, she says.
But all that has to start somewhere, Atterholt says. “It’s exciting that these birds made it into this part of Europe,” she adds. “Now that they know where these fossils are, hopefully field work will continue in this area.”