In the Hitch-Hikers Guide to the Galaxy, landscape manufacturer Slartibartfast likes to take elements of his favourite geological features and pop them together to make something extra special – allegedly how Scandinavia came about! On finding out about Macrauchenia, the last of the ancient and indigenous South American litopterns, I reckon old Slartibartfast must have had a bit of input in the creation of this seemingly impossible, wonderful creature.
Imagine a creature with the height (around 3m) and body of a humpless camel, legs that basically don’t match (the elongated upper portions of the front legs were made for high speed running, while the back legs were shorter, making it look as if it were crouching), terminating in cute little triple toed rhino-like trotters. Now, let’s add a long elegant neck, and a delicately pretty llama-like face (the name Macrauchenia means ‘elongated llama’, funny enough), ending in what some believe to be a little muscular trunk, not too dissimilar to that of an anteater. It’s not entirely surprising that most eminent scientists of the 19th century, including Richard Owen and Charles Darwin, had no idea how to classify remains of this beastie.
Charles Darwin sent the first fossils of these strange creatures back to England from South America during his adventures on board HMS Beagle. His notes mention that he found some large bones at Port St Julian, which he fancied as belonging to a Mastodon. He was right to compare these fossils with specimens that were known to him: Darwin wasn’t a comparative anatomist, so he could only compare fossils to what were known at the time. The experienced and highly intelligent Richard Owen was able to identify these fossils as belonging to something entirely new. Owen described and named the fossils as Macrauchenia patachonica and placed them as having affinities with the Ruminantia, with closer ties to the Camelidae (Owen was saying they were relatives of the camel).
Today we know of at least four species within the Macraucheniidae, which were the last of the now extinct Order of litopterns. These were an odd Order of animals belonging to the hooved mammals (ungulates), which had reduced toes (most had three, and one had just one toe like a horse). Fossils of this group have only been found in South America and Antarctica, showing it’s very small geographical range.
The skull of this creature reveals something fascinating: it may have had a trunk. The nasal opening high up on the head is known from animals with trunks (like elephants). It had been long believed that a long, prehensile snout had been used in a similar way to elephants, pulling down arboreal foliage for fodder. However, using carbon isotopes taken from dental enamel of skeletal remains show that Macrauchenia ate both grasses and leaves from trees; it appears a long snout may have allowed this animal to be more of a generalist eater. Likewise, those mismatched legs are thought to have maximised nimbleness on all territories, for this drama-llama needed to be able to twist and turn at high speed, on all terrains to avoid the predators of South America. And there were some impressive carnivores, including the nightmarish carnivorous ‘Terror-Birds’ or Phorusrhacidae, who it’s reckoned were Public Enemy Number 1 for Pleistocene herbivores.
These incredible animals were perfect evidence for Darwin’s theories, where evolution enables an adaptation to survive and thrive in a specific environment. That funny-looking trunk meant it could consume any sort of vegetation – Macrauchenia was not meant to go hungry. We now suspect that those legs were made for swerving and fast stops to evade anything with large teeth and an even larger appetite for pretty quadrupeds. Those powerful hind legs probably could also deliver quite a kick too.
Macrauchenia was an indigenous South American creature, existing from the earlier phases of the Miocene. As such, it was part of the complex ecosystem and food chain which predated the stream of migrating North American creatures to South America across the Isthmus of Panama, some 2.5 million years ago, in what we now call the Great American Interchange. Climate changes were occurring rapidly, and the great Quaternary megafaunal extinction event was happening. The populations of the last of the litopterns could cope with the ‘usual suspect’ predators – but soon found the environment populated by new predators, and increased competition from newly arrived herbivorous animals.
There was of course another creature which was crossing from continent to continent, perhaps the most lethal and destructive known on this planet – Homo sapiens. They did not need the Panamanian Isthmus to cross from one land mass to another, as their ingenuity and curiosity kept extending their territories regardless of any barrier in their way. Archaeologist Tom Dillehay’s relentless research at sites such as Chile’s Monte Verde shows that humans inhabited South America much earlier than once thought. Bone assemblages found at archaeological sites such as Argentina’s Campo Laborde and Paso Otero sites 4 and 5 from around 10,000 years ago include random bones of Macrauchenia which appear to be considerably older than the settlement sites themselves. However, there are petroglyphs in caves at Bahia, Brazil, which are considered to represent the unique Macrauchenia, which certainly would suggest humans did gaze upon this oddity of evolution. If they saw these creatures, it would be almost certain they also hunted them, so perhaps the conventional extinction date of c. 20,000 years ago is a bit too long ago for the last of their line. Two ribs of Macrauchenia have been found with cut marks (evidence of butchery) showing that the last small herds of this amazing creature may have survived until as recently as 10 to 15,000 years ago. More evidence is needed.
The land bridge of the Panamanian Isthmus between North and South America heralded catastrophic changes. Land displacement, sea current alterations, climate change, invasive species all created pressures on both the environment and native species of fauna of South America. The chill of the approaching Ice Age did not help the survival chances of a herbivore so perfectly adapted to its environment, not did the megafaunal-Malthusian stresses on resources caused by the migration of North American creatures. It simply may be that the arrival of humans, with even limited amounts of hunting and land management finally tipped the scales against the last of the fabulous Macraucheniidae.
Written by Rena Maguire (@JustRena)
Art by Tabitha Paterson (@TabithaPaterson)
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