The African Megafauna
The Habitat That Birthed Us
Africa is the only continent on Earth that harbours living monsters or megafauna. It’s the only place on Earth where megafaunal abundance and diversity still exist for real. But how did the African giants manage to survive, while the others living elsewhere perished? The key to answering such a perplexing question may come by looking at our own evolutionary history. Humans have lived in Africa in one form or another for millions of years, much longer than anywhere else, meaning that many of the living megafauna such as African elephants, white rhinos and leopards actually evolved alongside us. Our long evolutionary association goes a long way to explaining why Africa is still home to giants, and also why the rest of the world is sadly biologically impoverished.
So, let’s take a step back in time and look briefly at our early evolutionary history. The oldest hominid fossils discovered thus far were uncovered in East Africa and may date to around 4.5 million years ago. These few fragments of bone suggest that the earliest members of our group were already capable of walking upright, albeit in a rather awkward fashion, and it’s likely that they still spent most of their time in the trees. Their ability to walk on two legs is inferred from the structure of the leg and hip bone, but their curved hand bones and huge finger muscle attachments indicate for definite that they remained primarily arboreal.
The oldest known hominid for which we have a good collection of fossil remains is a creature known as Australopithecus, which first appeared some 4 million years ago. They quickly radiated into many different species, but remained surprisingly small, with the largest only reaching 5 feet in height. The males were probably much larger than the females, and it’s likely that they lived in extended family groups similar to modern chimps. They probably ate mostly fruits, plant roots and occasionally scavenged animal carcasses. Their fossils already show clear adaptations for upright walking, though their curved fingers and toes suggest that they still spent time in the trees, essentially they enjoyed the best of both worlds. One of the most fascinating pieces of evidence for upright walking comes from the 3.5 million year old footprints preserved in volcanic ash at Laetoli, Tanzania. These footprints were left by a small group of Australopithecus, probably a mother, father and their tiny child.
These new hominids essentially resembled chimps, except for their upright walking. They were pioneers of a new way of living, striding out into a new kind of habitat, Africa’s predator rich savannah. It’s almost certain that one species of Australopithecus was our direct ancestor. For 3 million years, hominids were exclusive to Africa. This is such a vast amount of time, that it’s difficult for us to truly grasp its scale, or more importantly to understand its implications. Often, we overlook just how dangerous this environment was for our ancestors, and also how it shaped both our bodies and minds. If we truly want to understand ourselves, our relationship with our fellow animals and our current domination, then we need to consider this particular historical period in some depth.
Life in Prehistoric Africa
A Strange Elephant
Deinotherium- A Monster Elephant
Deinotherium was a gigantic cousin of the modern elephants and lived between 20 and 1.4 million years ago and were especially abundant during the era of Australopithecus some 3-4 million years ago. There were roughly three time heavier than any modern elephant and approached modern giraffes in terms of height, with the males standing 13 feet at the shoulder, whilst the slightly smaller females stood 11 feet at the shoulders. Like their modern cousins, they were browsers rather than grazers, feeding on trees and shrubs predominantly. Although they were plant eaters, their sheer size and baby-defending instincts made them very dangerous. They possessed specially shaped tusks and probably fed by felling trees and then stripping their bark. Our Australopithecine ancestors would have been aware of the danger posed by these colossal creatures.
Our transition from tree dwelling apes to walking hominids may sound somewhat glorious or heroic, but in reality it was our biggest nightmare. As our ancestors adapted to a terrestrial lifestyle they must have been extremely vulnerable. Even today, the African savannahs harbour a bewildering menagerie of large, well armed and very dangerous animals, which in turn are preyed upon by some of the most fearsome predators ever to evolve. The savannah was not some wonderful grassy utopia but instead a cold, unforgiving and ultimately lethal evolutionary arena. They were prowled by a wide range of hyena species, including the modern forms, but also among their ranks were giant, lion sized versions. There were also wolf sized, blade-toothed dogs and sabre-toothed cats such as Megantereon and Homotherium, who were actually the ancestors of the American Smilodon and scimitar cat respectfully. Alongside these bizarre feline forms, lived prides of lions, leopards and cheetahs.
You can hardly imagine a worse sort of environment for a small and defenceless hominid to try to enhance their walking skills. It’s likely that patches of trees served as important sanctuaries, but sometimes even these refuges weren’t enough, as some cats such as the leopard were and still are very adept tree climbers. It’s actually quite hard to believe that our ancestors survived at all with so monstrous predators, but they were only half the problem.
Whenever we think of dangerous animals, we often imagine something large and ferocious, but few people realise that in actual fact the most dangerous large animals in Africa are its lumbering vegetarians. Today a tourist visiting an African park is far more likely to be killed or injured by herbivores than carnivores. In fact four out of the five most dangerous African animals are herbivores (elephant, Cape buffalo, hippo and rhino) with the fifth being a predator (the lion). Back in the distant past, before Africa was subjected to the affects of man-made habitat destruction, it’s likely that these large and dangerous animals were even more plentiful than they are today. It makes you wonder and think just how lucky we all are to exist today.
The Cat That Hunted Humans
Dinofelis was a species of sabre-toothed cat that lived on the savannahs of Africa and parts of Eurasia between 5 and 1.5 million years ago. It was an ambush predator that needed to stalk within close range, taking its prey by surprise. The structure of the cat's forelegs suggests that it was a very adept tree climber like the leopard. For our ancestors, this was the creature of nightmares as it was capable of penetrating even our safest hiding places. Several australopithecine skulls have been found with tooth marks on the cranium, possibly made by Dinofelis- chilling evidence of our long history as a prey item.
Predator or Prey?
When the first hominid fossils were uncovered in the 19th and early 20th centuries, scientists felt the need to demonstrate how human like these creatures were, and so a narrative was established that emphasised our ancestors hunting prowess. It seems that the idea of our ancestors skulking in trees and living off vegetation was just not noble enough for the wider world. Paleoanthropologist Raymond Dart took this to the extreme when he interpreted australopithecine fossils found in several South African caves as definitive evidence that we started out life as blood thirsty, meat eating cave dwellers. Alongside the hominid bones were numerous bones from other animals which were interpreted as the remains of kills brought home to be eaten in relative safety. Dart even went as far as interpreting the remains of antelope jaws as possible man-made tools. He postulated that they could have used them as hunting clubs, saws and digging tools. Some of the hominid skulls showed signs of severe fractures which were judged by Dart to have been the result of inter-group warfare using the ‘weapons’ he’d identified.
In recent times though, careful re-examination of these fossils has helped to reveal the horrible truth. Palaeontologist Bob Brain has postulated that in actual fact the hominids were not hunters and did not live in caves. Instead it’s likely that they were dragged into the cave to be consumed by ape eating carnivores and bone gnawing porcupines looking for somewhere safe to enjoy their meal. Trees that often overhang cave entrances serve as perfect ambush and larder sites for cats such as leopards. Their leftovers (including our ancestors) would have dropped into the cave below.
Brain’s theory is vindicated by a gruesome piece of evidence from another South African cave at Swartkrans. Here a young australopithecine skull was found with two holes on the top of the cranium that exactly match the lower canines of a leopard. They were either made during the kill or as the cat dragged its poor victim up a tree. These South African caves have yielded around 140 fossilised hominid skulls, many of which bearing tooth and claw marks from big cats and hyenas. The high proportion of primate fossils in these caves suggests that there was probably a species of predator that specialised in hunting baboons and hominids. It’s clear that ‘Dart’s hunters’ were in fact unfortunate victim. You’ve heard the phrase ‘Man the hunter’. Well, for most of our history we were actually ‘Man the hunted.’
Even today, we modern humans aren’t totally safe from predators, especially those who live in wilderness environments without access to modern rifles. Anthropologists recently estimated that among the Ache people of Amazonia up to 6 per cent of all deaths among young adults were due to jaguar predation. Other scientists have found evidence that nearly 400 people have either been killed or injured by African big cats and hyenas in Uganda over an 80 year period. This is an incredible statistic when you consider that modern humans are substantially bigger than early hominids, have larger brains, are often armed with some kind of weapon and live with a greatly reduced predator population. So, by digesting these facts, you get an idea of just what life was like for our ancestors.
Africa’s megafauna have helped shape not only our bodies, but also our minds. Those millions of years we spent living in fear of monstrous carnivores perhaps explaining phenomena as diverse as our fear of the dark, our proficiency with ball throwing games and our fascination with monsters in general.
The Handy Man
The Turn of the Tide
Often when we watch nature documentaries, we are often subjected to the sight of vultures squabbling over a carcass; we often view such scenes with a degree of distaste. But the ironic thing is that for most of our history, we were right there alongside them fighting for meat scraps. Indeed, our ancestors would have viewed a carcass with relish rather than disgust.
From around 2.5 million years ago our ancestors started using simple stone tools in order to gain access to carcasses. It was a rather simple and modest innovation, but it was an innovation that transformed our fortunes and ultimately transformed our relationship with the Earth’s megafauna. The first animal bones found in association with stone tools date from around 2.5 million years ago. There are several theories about what these associations could mean. Perhaps these clusters of bones and tools represent camps to which food was brought? Or were they the sites of hominid kills? Or perhaps they were simply the remains of animals that our ancestors scavenged. By interpreting their tools, it seems that the latter is more likely than anything else. There is no evidence that these stone tools were used on spears or arrows, and so hunting Africa’s megafauna close up with such artefacts would have been suicidal. It’s possible that these stone edges were used to fashion wooden hunting spears, but evidence for this is nonexistent.
It’s amazing to think that after the invention of sharpened stone flakes, there were no more technological advances for another 1 million years, until Homo erectus invented the teardrop-shaped hand axe 1.5 million years. Such a lack of technological advancement is totally unimaginable to us now and serves to illustrate just how far from us, these early hominids were in their mental and cognitive ability.
The First Human
A Bizarre Herbivore
We often think of Africa’s Serengeti as a beautiful untouched wilderness. A place that serves as the last stronghold for the animals that ruled the Earth before humanity, but this is sadly not the case. The Serengeti is indeed wild, with a primal edge; but it’s not some intact piece of prehistoric wilderness, it is also biologically impoverished, just not as much as the Americas or the Australia. Africa did suffer megafaunal extinction, but it occurred far back in time, long before the emergence of our own species, at a time when another successful human species was abroad in Africa, Homo erectus.
We know that large animals played an increasingly important role in the diet of Homo erectus through examination of their teeth, which show a pattern of wear very different from that of earlier hominids. This small but significant change coincides with the development of butchery. Homo erectus used their stone tools to strip meat from carcasses and to cut through tendons and ligaments, allowing joints to be broken. In some cases, Homo erectus actually had first access to the bones, because carnivore tooth marks appear on top of the marks made by humans, this piece of information is significant because it seems to demonstrate that Homo erectus was capable of hunting large game.
Africa’s megafaunal extinction occurred around 1.4 million years ago and is intriguing because it occurred right at that the time when Homo erectus was developing this new stone tool technology. It seems clear, that our ancestors had now shifted their status, from prey to predator. So, which species succumbed and which survived? Well, the survivors are basically the animals that still survive today, they survived because they learnt that they either had a new predator or new competitor in their midst and evolved essential survival behaviour in order to deal with us. This is why the living mega herbivores of Africa are among the most dangerous animals in the world to humans, because they know that among the best ways to deal with an encroaching human being is chase them away, while many of the rest simply run away, another very effective survival strategy.
The number of victims is considerable and includes all of the sabre-toothed cats including Dinofelis, Megantereon and Homotherium, the latter two managed to survive elsewhere for much longer. Indeed, the first modern descendants of Homo erectus who first encountered the Americas beheld variants of these creatures, for Megantereon was probably the direct ancestor of Smilodon, while Homotherium is also known as the scimitar cat and survived in the Americas until 10,000 years ago. It must have been a rather strange reunion, two deadly predators separated from each other for over a million years, suddenly living alongside each other again, albeit for a short time.
Among the herbivores that succumbed were the majority of the elephant family, including the enormous Deinotherium, which was the largest land mammal on the planet at that time, being as tall as a giraffe but weighing fourteen times as much. It was three times bigger than any living elephant. Africa today, still houses two species of hippo, the infamous modern hippo, among the most dangerous animals you’ll ever come across, and the less well known pygmy hippo which lives in the forests of Western Africa. But 1.4 million years ago, there were two more species, which looked remarkably similar to both modern species, but they became extinct at around this time.
Among the strangest creatures to succumb was the Ancylotherium, it was one of those bizarre creatures that seemed to have been assembled by using the body parts of other animals. Its head was similar to a horse, while its huge body was reminiscent of a ground sloth. It possessed short, but powerful hindquarters and long, muscular arms with large claws which were used for pulling down tree branches in order to browse on vegetation. Ancylotherium’s long claws meant that it probably walked on its knuckles similar to that of a gorilla.
The spectacular menagerie also included certain animals that would have look startlingly familiar to human eyes, but those same eyes would have been astonished by their proportions. There were giant versions of warthog and a giant version of wildebeest, plus a much larger zebra species. There was even a bizarre looking relative of the giraffe which possessed two large deer like antlers called Sivatherium. Our ancestors also lived alongside two huge baboon species, with one roughly the same size as us, the other reaching the size and weight of a gorilla.
All of these creatures plus more disappeared just at the time when Homo erectus was developing its sophisticated stone tool technology and also experimenting with fire for the first time. There is archaeological evidence that demonstrates that erectus frequently included large animals in its diet, but not enough to state with total confidence that they were responsible for this prehistoric extinction. The evidence is more circumstantial than concrete, but if the prehistoric megafauna of Africa really did succumb to the growing intelligence of Homo erectus, then it marks the first major environmental impact of our line. It could well be that our domination of the planet and its life started here. If this is indeed true, then in future we need to consider our deep past, if we want to gain a true understanding of our relationship with the natural world.
More to follow...