Africa has chimpanzees, bonobos, gorillas, Asia, the Orangutans and gibbons. yet the New World primates are mostly vert small-why is this?
Is there any reason why the S. American ecosystem cannot support great apes?
There’s lots of large primates in South America. They’re known, taxonomically, as H. sapiens.
Just because an ecosystem ***can ***support large primates, doesn’t make them magically evolve that way. If there was no advantage in becoming larger, why would they?
No doubt South American ecosystems could support large primates, but it just so happens none ever evolved. No mostly terrestrial primates such as baboons or Patas Monkeys seem to have evolved either.
You might as well ask why Old World primates, even the arboreal ones, never evolved prehensile tails. (The only primates with prehensile tails are in the New World).
South America has many kinds of arboreal animals - opossums, sloths, anteaters, primates, some carnivores, porcupines, squirrels, many other rodents - but oddly enough has no gliding forms. Africa, Asia, Australia, and North America all have a variety of gliding mammals which have developed independently from different lineages - flying lemurs, flying squirrels, scaly-tailed squirrels, Australian gliders, etc.
Essentially, Ralph’s examples suggest that by “large primates” he is talking apes. And it’s important to realize that since the Pliocene, apes have been a declining group. Even in Africa, only about a third of the continent supports any of the three or four species of ape indigenous to that continent. The gibbons, siamang, and orangutan together are the Asian apes, grouped geographically instead of taxonomically, and their combined ecological area is a fairl small portion of SE Asia and a few adjacent large islands in the Malay Archipelago.
Large-bodied catarrhine monkeys, mostly terrestrial in habitat, occupy the plains and savannah areas of Africa, South Asia, and various habitat areas scattered around other parts of Asia. Likewise, the large-primate econiche is occupied, such as it is, by large-bodied platyrhine ‘monkeys’, the Cebids, in South America, e.g., the howlers. They are nowhere as large as the apes, but, outside Africa, neither are the catarrhines. And because South America has almost no tropical plains and savannah, no known large terrestrial Cebids evolved. (Plenty of plains and savannah, but it’s mostly warm-temperate in climate, if not necessarily geographically.)
It is worth noting that cryptozoology mentions a supposedly-photographed ground-living large form, looking for all the world like a refugee from the opening scene of 2001 but predating it. Most likely a hoax, but if not it would likely be an extremely rare aberrantly large Cebid. It is, however, very unlikely to be an actual undescribed species, as a viable population, no matter how secretive of habit, would be able to survive in the moderately-populated area where the supposed photographs were taken. (By comparison, this is not “there might be a Sasquatch in the wilds of the Canadian Rockies” but “there are ape-men running around Mississippi.”)
Why I made an issue of the two kinds of monkeys (actually the marmosets and tamarins constitute a third major group) is that, contrary to popular terminology, the catarrhine “Old World” monkeys are more closely related to the apes and man (which which they form a large clade) than they are to the platyrhine “New World” monkeys.
Final issue is what evolutionary force would produce a large primate? It needs to evolve to fill a niche – what niche would it fit into at a competitive advantage to what’s already in that niche?
It’s hard to say, but the fact that they have evolved independently at least three times suggests that there is a fairly strong advantage. In addition to the apes, Madagascar also produced at least two lines of large lemur. The largest of these was considerably larger than the biggest gorilla, and the smaller was comparable with a human.
It seems that these giant priimates evolve because primate intelligence when combined with a low quality diet of leaves favours an extreme K-strategy, ie an extremely long lifespan, prolonged juvenile phase, minimla mortality etc. The most effective way to do that is to get as big as possible.
As for why these animals have an advantage over what is already in the niche, there are two possibilities. The first is that nothing is in that niche. Every niche isn’t occupiied in any environment and it may be that the niche of browser and opportunistic forager simply isn’t occupied in may systems. But even if the niche is occupid by something like a tapir or panda then the ability of primates to climb and their intelligence may provide sufficent advantage to allow them to be competitive even if the niche is already filled.
Maybe you are talking about the 1917 DeLoys expedition into the Sierra de Perijaa, between Columbia & Venezuela?
This area
is still pretty wild, and in 1917 an unknown species was certainly possible. Or perhaps a then rare species which is now extinct?
It doesn’t appear to be a hoax.
*"Between 1917-1920, de Loys and his men were searching for oil around the River Tarra and Rio Catatumbo at the Venezuelan - Colombian border in South America (Heuvelmans, 1959). This mountainous region, the Sierra de Perijaa, was heavily forested, and that time was inhabited by the ‘dangerous’ Motilone Indians.
One day, while de Loys and his crew were resting near the Tarra River deep in the jungle, two monkeys suddenly stepped out of the woods, screaming and shaking branches. They were holding onto bushes, walked upright then broke off several branches, waving them like weapons. When the monkeys threw their own excrement at the terrified de Loys and his exhausted companions, they grabbed their guns and fired at the more aggressive-looking male, but killed the female. The male stepped aside, though wounded, but disappeared in the forest.
Since de Loys and his people had never seen such large monkeys, he wanted to preserve the carcass. When finally de Loys returned home with the only remaining evidence, the picture, which he had placed into his travel-notebook, he basically forgot about his encounter with the unknown monkeys. Years later his friend, French anthropologist Georges Montandon flipped the pages of de Loys’ notebook, and discovered the photo. Montandon got an idea.
Although Professor Montandon was familiar with most of the monkeys discovered to that date, he had never seen one like that in de Loys’ picture. Montandon speculated that the large monkey on the picture was a very human-like creature. It had no tail. Its size according to de Loys was 4 feet 5 inches. It had 32 teeth. It had all the features like the anthropoids in the Old World have and, therefore must be an anthropoid Ape. Not just any Ape, but an ‘American’ Ape – a ‘Missing Link!’ He asked de Loys for more details, calculated some measurements by estimating and comparing the size of the box with the body on the picture, and in 1929, convinced de Loys to tell the story to the Illustrated London News (Loys, 1929 op. cit.: Keith, 1929; Heuvelmans, 1959; Hill, 1962) Shortly thereafter, Montandon published his statement in the Journal de la Societe des Americanistes (Montandon, 1929a); then wrote another note which he presented at the French Academy of Sciences in Paris. (Montandon, 1929b). ‘Montandon went so far as to create a new genus Amer-anthropoides for the reception of the new animal, giving it the specific name loysi in honor of its discoverer.’ (Hill, 1962).
At the meeting of The French Academy of Sciences Montadon tried to present some convincing ‘evidence’ about his major discovery of the American Ape, a so far unknown ‘American version’ of the African chimpanzee and gorilla, and the Asian orangutan. He and de Loys, - who under Montandon’s pressure also tried to support the new discovery hypothesis, - had to face with numerous questions at the Academy. Naturalists and anthropologists questioned them very suspiciously. They raised many questions about the photograph: the size of the monkey sitting on the box, about her ‘missing’ tail, her set of only 32 teeth, her spider-monkey-like face (Joleaud, 1929), her female sex organ - that resembled that of a male spider monkey. (Female spider monkeys have a long, bulbous clitoris, that people, even today often mistaken for the male sex organ).
The skepticism and some of the criticisms resulted in heated debates, often ridiculing Montandon’s alleged hypothesis as a fraud (Keith, 1929 op. cit.; Heuvelmans, 1959). When Montandon ran out of more convincing arguments in order to support his fancy hypothesis, he tried to bring up some anecdotes based on stories of Indian tribes like about the guayazi, the di-di, and the vasitri or ‘big-devil’ that believed to attack women."
*
If it was a hoax, then why would de Loys just put the photo aside, to be discovered by chance later?
Note that Heuvelmans devotes an entire chapter to South American apes (or tailess monkeys) in “On the Track of Unknown Animals”, there is some other evidence. :dubious:
My WAG is just that this was a just single weird aberrant spider monkey.
Dr Deth: Yep, that’s the creature. It’s been decades since I read any Heuvelmans, and I misremembered the DeLoys account as “just another yeti/bigfoot sighting” – not out of the realm of posibility, but to be taken with a large block of rock salt.
On cryptozoology, my position is unclassifiable – I believe many of the “native traditions” and “sober sightings” stories justify further investigation in the field, when someone wants to underwrite it, but I’m far from being a True Believer in the hypercredulous sense. In the interim, I think they deserve reporting as just what they are, unconfirmed evidence suiggesting that something worth investigating and being either described or debunked is there.
Just by coincidence, I read an old story (in “WHEN MAN IS PREY”; ed. by Michael Tougias, 2008. He relates the story of two American adventurers, who were traveling in the southern part of the Mexican state of Zacatecas, in the year 1824. One night, camped in the valley of Oaxaca, they were attacked by several large ape-like monkeys, of an unknown species. The local indians called these monkeys “zambos”, and the American drove them off, after firing several shots at them. According to the locals, these zambos had killed several men.
Anybody know if these stories were true?
Since there is no evidence beyond hearsay for any “large ape-like monkey” anywhere in the Americas, and certainly none that might be capable of killing a human under normal circumstances, one can say pretty surely that this story is bunk.
Regarding the “de Loys Ape” cited by DrDeth, I concur that it is nothing more than a spider monkey. For one thing, it lacks thumbs - this lack is a key spider monkey characteristic.
Not anymore, now that we ourselves are classified as apes. We keep the simian flag flying high. Go apes!
Yet another wonderful username/post juxtaposition! 
Agreed, in the same sense that I enjoy watching the dinosaurs on my lawn, pulling up worms and chirping to each other.
There aren’t many large animals in South America of any sort, period, are there?
Not many extant large mammals (llamas, tapirs, and cougars come to mind), but there have been more large mammals in the past, like the giant sloth. If we consider birds and reptiles, that expands the set a bit, too.
The largest one still remaining is the tapir. But in the Pleistocene the place teemed with big mammals, including many species of ground sloth (some as large as an elephant), glyptodonts, several species of mastodonts (gomphotheres), horses, large llamas, giant short-faced bears, saber-toothed cats, lions (the same species as the modern African Lion, but a different subspecies), rhino-like toxodonts, and weirdies like the Machrauchenia, not to mention giant flightless predatory birds.
Many of these were probably killed off by humans after their arrival a bit before 12,000 years ago.