Prehistoric Apes

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https://twilightbeasts.wordpress.com/201...ive-giant/  
 
Following in the footsteps of his predecessors the German palaeontologist, Ralph von Koenigswald, scoured Chinese medicine shops and examined their piles of dragon bones before they were ground down to dust. He was searching for more Homo erectus fossils to potentially point to new sites. Amongst the many different fossils he saw, von Koenigswald discovered a molar. A massive molar. He spent 4 more years searching the little obscure pharmacies, and was rewarded with three more massive teeth. These molars were enormous. The teeth had features which were very similar to orang-utan teeth, leading Von Koenigswald to propose these fossil teeth belonged to a new species of extinct ape, which he named Gigantopithecus (literally meaning ‘giant ape’).
At the height of the Second World War, von Koenigswald was held as a prisoner of war on the Island of Java. Luckily, his four teeth were safely buried in a garden. With von Koenigswald and his original fossils safe, but both temporarily out of the picture, a colleague at the American Museum of Natural History, the anthropologist Franz Weidenreich, examined casts of the four teeth. Weidenreich theorised they were the teeth of an extinct species of human. An extinct species of giant human. The theory lasted for nearly twenty years, with Weidenreich even writing a fairly convincing book, Apes, Giants and Humans. For a while, these four teeth were evidence that a giant human thrundled across the Asian landscape, and was the ancestor of modern Asian and Australian humans.
In the 1950s, Chinese palaeontologists sought to find more fossils of these mysterious giants. Teams headed around the provenance in search of the very source of these fossils, talking to villagers and farmers for possible leads. One team found a number of teeth in-situ in reddish cave sediment; the first fossils found linked to stratigraphy. Another team had more luck and discovered over a thousand teeth and a fossilised jaw. Gigantopithecus was a giant ape, not a human ancestor.

Three species of Gigantopithecus have been discovered so far: G. blacki, G. bilaspurensis and G. giganteus. Fossils of this Genus have been found across Nepal, China, India and Vietnam, and in sediments which suggest the group originates around 9 million years ago. These were a very successful group of apes. The largest, and the first species discovered in that Chinese medicine shop, was Gigantopithecus blacki. This ape had some pretty impressive statistics: it may have been around 3 meters tall, and weighed as much as three gorillas. This was the largest ape (so far discovered) ever to have walked the Earth.
As with any extinct creature, clues to the size and lifestyle can be inferred from the fossils (and trace fossils if they exist). Current fossils finds of Gigantopithecus blacki suggest a slightly restricted geographical range to China and Vietnam. With no post cranial bones found so far, and only a handful of jaws and a few thousand teeth, can we really provide an accurate description of this giant, let alone suggest how it lived?
Surprisingly, we can get an awful lot of information from these fossils.
The teeth and jaws show that this creature was an ape. Unmistakably an ape. But an ape of gigantic proportions. We can make a fairly good guess to the size of this animal based on the size of the jaws; it is highly unlikely that this was an average sized ape with a ridiculously oversized head. Keeping it simple, researchers have used measurements from orang-utan skulls to work out the size of G. blacki’s skull, by scaling upwards. (It is thought that orang-utans were close relatives, and the two species had similar feeding habits.) From the estimated head size, you can work out the body size, the head to body ratio of 1:65 (using the gorilla as the model assuming G. blacki didn’t swing through threes like an orang-utan). So with a little maths, and tweaking of ratios to best fit how this big ape would have moved, researchers came up with the height and weight. Admittedly, this method is based on a skull size which is calculated by a very small number of jaws which wouldn’t provide an exact average and we have no idea how G. blacki moved. But from what we have, the estimates are not too bad. More complete fossils will provide more precise data.

The teeth themselves, and there are a lot, provide some really interesting information. The flat surfaces, and the low cusps, of the molars and premolars suggest that it was chewing a lot of tough plant material, such as bamboo. Firing beams of electrons at the teeth with a Scanning Electron Microscope (SEM) shows the smallest scratches, and even tiny particles on the teeth. The SEM highlighted little phytoliths on the teeth, which are tiny secretions made by plants and they remain after the plant has long gone. With phytoliths present and some actually embedded in the surface of a couple, Gigantopithecus blacki was definitely eating grasses. Although these small silica blobs don’t give the species of plant, it is more than likely that they were from bamboo; this grass was in such an abundance, more than enough to sustain the appetite of such a large herbivore.

The sex lives of this big ape can also be worked out by the teeth. A very detailed study of 735 teeth grouped them into two different size ranges, big teeth and smaller teeth. These are not the teeth of different species; this size range is typical for species with sexual dimorphism: male Gigantopithecus blacki were much larger than the females, similar to gorillas today. Male gorillas are much larger than females, and will have several in their harem. Possibly G. blacki had a similar sex life with males using their larger size to compete for females and hold a harem.

Our own relatives, Homo erectus would have seen Gigantopithecus blacki. Two caves in China (Jianshi Cave and Longgupo Cave) and one in Vietnam (Tham Khuyen Cave) have revealed fossils of both G. blacki and Homo erectus. Radiometric dating at Tham Khuyen places the fossils there at around 500,000 years ago and Longgupo Cave has produced an even older date between 1.5 and 1.9 million years ago. Across Asia, one species of human co-existed with these giants for over a million years. But then, around 100,000 years ago, Gigantopithecus blacki, the last in the line of these apes, became extinct. Their demise may have been dues to a series of unfortunate events. At a similar time, giant pandas had moved to the same range, competing for the same food. Another species of ape, Homo sapiens was fairly new to the scene and may have even hunted G. blacki for food (there is no direct evidence for this, but primate meat is a large source of protein in Africa). Their specialist diet may have provided the fatal blow: bamboo are known for their periodic mass die offs, and take the food source away from a specialist eater and it will be in trouble.
Currently no complete skeletons, or even post cranial bones have been found. The acidic soil of forests, along with the many different types of minibeasts living there, break down flesh and bones fairly rapidly leaving nothing left (this is why the fossil record for chimpanzees, gorillas and other forest dwelling animals is so poor). Finding teeth and jaws in caves does not mean these were living in the caves. It is more likely they represent individuals who were killed, or scavenged, and dragged into the caves. More fossils will give us more information on these giants.
Written by Jan Freedman (@Jan Freedman) Reply