Have you ever wondered where walking comes from? It’s something most of us do every day, And new fossil evidence adds some serious twists and turns to our understanding of the evolution of human mobility. Let’s get the confusing part out of the way first: humans are taxonomically classified in the family Hominidae. This is also the family that includes Neanderthals, or Homo neanderthalensis, as well as other human species like Homo habilis, Homo erectus, the genera Ardipithecus and Australopithecus. But this family also includes modern day non-human great apes and their ancestors. So that’s what we refer to as hominids: all ancient and modern day primates. Within the hominids, there’s a group we refer to as hominins, which refers to only modern humans, extinct humans, and our immediate ancestors. You and me, Homo sapiens, are the last living member of this group. And ever since we started sorting organisms into taxonomic classifications, one of the key defining features that separates us hominins from other primates has been bipedal locomotion: simply put, our ability to walk around on two feet. Non-hominin primates—because yes, humans are also primates—do not demonstrate this behavior as their primary form of locomotion. Our closest living relatives use their long arms and knuckles for quadrupedal walking. And by looking at the structure of a primate’s pelvis, shoulders, elbows, hands and other anatomical features, we can learn a lot about the way an animal moved, even if we only have their bones. Studying the characteristics of several ancient primate fossils has indicated that these ancestors may have used many different methods of locomotion, which has left paleontologists with a bunch of questions. When did walking exclusively on two feet become the primary boogie for hominins? Or what about the knuckle-walking that we see in modern great apes, when did that appear? It’s been difficult to tell from the fossil record so far… until a recent discovery added a significant new piece to the puzzle. A team of paleoanthropologists just unearthed a new ancient ape species, which they’ve named Danuvius guggenmosi. Very catchy. This species lived in what’s now Germany approximately 11.6 million years ago and its anatomy suggests that it moved in a really exciting way. It’s a dryopithecine ape, an ancestor of modern day humans, and it was probably about the size of a baboon. The fossil has long arms, flexible elbows and strong hands, all of which indicate that it most likely did a lot of swinging from trees. This is similar to bonobos, chimps and gorillas, whose anatomy allows them to walk on their knuckles on the ground and occasionally do some tree swinging. But D. guggenmosi’s lower limbs, specifically its hips and knees, were different. They were extended, meaning its legs could have straightened to a full standing position, and its knees and ankles were capable of bearing weight. All of this indicates that the animal probably got around using a movement method previously unheard of in paleoanthropology— what these researchers are calling ‘extended limb clambering,’ or the equal use of both its upper and lower limbs. Arms to hang and swing, legs to walk upright. This essentially represents a missing link in the evolution of primate movement. Up until very recently, we’ve been pretty much in the dark about exactly when and how bipedalism may have evolved. This discovery pushes the development of walking on two feet to way before the time we had in mind: about 5 million years earlier, in fact. It totally upends the way we’ve been thinking about all of this. Because most lines of thinking in primate evolution have gone down the route that hominins evolved bipedalism when splitting off from a quadrupedal ancestor, but this newly discovered fossil is a common ancestor of both bipedal hominins and modern-day knuckle-walking great apes. Which then means that modern apes may have evolved their knuckle-walking after this common ancestor had already developed an early bipedal mechanism. In addition to giving us brand new data points to inform our understanding of human evolution and our relationship to our living cousins, this discovery is also cool because the fossil was found in Germany. Many of us may picture ancient apes exclusively wandering around the African continent, but many of our ancestors were living in Europe and Asia in the mid- to late Miocene epoch. And here’s the most exciting part to me: between this fossil in Europe and the earliest evidence of early human development in Africa, there’s a couple million years missing. We don’t know what happened in between: how does bipedalism get from a species like D. guggenmosi in Germany to the next earliest bipedal hominin species in the fossil record, found in Africa? There’s still a lot to unearth. So much of human history, the very beginnings of where we come from, just waiting to be dug up out of the dirt. What are you interested to see paleontologists dig up next? Let us know down in the comments below, and for more on upturned evolutionary ideas check out this one on dinosaur development. Subscribe to Seeker for all your breaking news on ancient stuff, and I’ll see ya next time. Thanks for watching.