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 19^th century, including Richard Owen and Charles Darwin, had no idea how to classify remains of this beastie.

A small herd of the strange looking litopterns. It is not difficult to imagine groups of these creatures dotted around the hot plains of South America. Art by Tabitha Paterson.

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.

Two big South American Terror Birds (Phorusrhacidae). These were the apex predators of the isolated South American continent until around 2.5 million years ago. (Image by Roberto Díaz Sibaja. Image from here)

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.

The Great American Interchange. North and South America were separate continents for millions of years. When they joined together, creatures from the north and south travelled freely to new lands.  (Image from here)

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)

Further Reading:

Adams, D. 1979. The Hitch-Hikers Guide to the Galaxy. London: Pan. [Full book]

Alvarenga, H., Jones, W., & Rinderknecht, A. (2010), ‘The youngest record of phorusrhacid birds (Aves, Phorusrhacidae) from the late Pleistocene of Uruguay’. Neues Jahrbuch für Geologie und Paläontologie-Abhandlungen.  256.2. 229-234. [Full article]

Bayón, C., et al. (2011), ‘Following the tracks of the first South Americans’. Evolution: Education and Outreach. 4.2. 205-217. [Full article]

Cid, A. S., et al. (2014), ‘ Na, K, Ca, Mg, and U-series in fossil bone and the proposal of a radial diffusion–adsorption model of uranium uptake’. Journal of Environmental Radioactivity.  136. 131-139. [Abstract only]

Chichkoyan, K V, (2013), South American Extinctions, a case study: the Rodrigo Botet Collection of the Museum of Natural Science in Valencia, Spain. Assemblage 12. pp. 28-42. [Full article]

Darwin, C. (1862), The Correspondence of Charles Darwin:, Volume 10. Cambridge: Cambridge University Press. [Full online correspondence]

Deschamps, C. M. (2013), ‘Late Cenozoic mammal bio-chronostratigraphy in southwestern Buenos Aires province, Argentina’. Ameghiniana. 42.4. 733-750. [Full article]

Dillehay, T., et al. (2008). ‘Monte Verde: seaweed, food, medicine, and the peopling of South America’. Science. 784-786. [Abstract only]

Fariña, R. A., Blanco, R. E., & Christiansen, P. (2013). ‘Swerving as the escape strategy of Macrauchenia patachonica Owen (Mammalia; Litopterna)’. Ameghiniana. 4. 751-760. [Abstract only]

Flegenheimer, N., Miotti, L., & Mazzia, N. (2013). ‘Rethinking early objects and landscapes in the Southern Cone: Fishtail-point concentrations in the Pampas and Northern Patagonia’. Chapter 21. [Full chapter]

Guérin, C., & Faure, M. (2004).  ‘Macrauchenia patachonica’, Owen (Mammalia, Litopterna) de la région de São Raimundo Nonato (Piauí, Nordeste brésilien) et la diversité des Macraucheniidae pléistocènes’. Geobios. 516-535. [Abstract only]

Huxley, T. H. (1861). ‘On a new species of Macrauchenia (M. Boliviensis)’. Quarterly Journal of the Geological Society. 1-2.  73-85. [Abstract only]

Lynch, T. (1999).  ‘The earliest South American lifeways’ in  Salomon, F and Schwartz, S (eds) The Cambridge History of the Native Peoples of the Americas Volume 3: South America, Part 2. Cambridge: Cambridge University Press. 188-206. [Book]

Marshall L G, et al. (1982). ‘Mammalian evolution and the Great American Interchange’. Science.4538. 1351-1357. [Abstract only]

Martínez, G., Gutiérrez, M. A., & Prado, J. L. (2004). ‘New archaeological evidences from the late Pleistocene/early Holocene Paso Otero 5 site (Pampean region, Argentina)’. Current Research in the Pleistocene. 21. 16-18. [Full article]

Martínez, G., Gutiérrez, M. A., & Tonni, E. P. (2013). ‘Paleoenvironments and faunal extinctions: Analysis of the archaeological assemblages at the Paso Otero locality (Argentina) during the Late Pleistocene–Early Holocene’. Quaternary International. 299. 53-63. [Abstract only]

McFadden, B.J and Shockey, B. (1997). ‘ Ancient feeding ecology and niche differentiation of Pleistocene mammalian herbivores from Tarija, Bolivia:morphological and isotopic evidence’. Palaeobiology. 23. 1. 77-100. [Full article]

Prado, J. L.,and Alberdi, M. T. 1999. ‘The mammalian record and climatic change over the last 30,000 years in the Pampean Region, Argentina’. Quaternary International. 57. 165-174. [Full article]

Politis, G. G., & Messineo, P. G. (2008). ‘The Campo Laborde site: new evidence for the Holocene survival of Pleistocene megafauna in the Argentine Pampas’. Quaternary International. 191.1. 98-114. [Abstract only]