Comparison of North American Camelids with Extant Asian and South American Camelids

Part 1: Camelus vs Camelops 

Recent genetic evidence has shown that, contrary to previous belief, the extinct western camel (Camelops hesternus) of North America was much more closely related to extant camels than to llamas and alpacas. While Camelus and Llama had a common ancestor roughly twenty five million years ago, Camelus and Camelops had a common ancestor as recently as ten million years ago, placing the western camel firmly in the Camelini tribe rather than the Lamini tribe.  

The western camel was about twenty percent larger than modern Dromedary and Bactrian camels. It would have weighed as much as eight hundred kilograms and measured two point two metres at the shoulders. It is not known exactly whether or not Camelops had any humps, but if they did they may have had as many as two. The modern one-humped camel (Camelus dromedarius) has shown to have two humps as an embryo, one of which it loses before birth. Adult male dromedaries will sometimes grow a vestigial front hump as well. This suggest that having two humps (like the Bactrian camel, Camelus ferus and Camelus bactrianus) is the ancestral condition and may possibly have been shared with several ancestors and cousins of modern camels. The western camel has also been shown to have very Camelus-like feet with toes much more spayed than those of a llama. These would give good amounts of traction and support and allowed western camels to be able to travel very long distances efficiently and ergonomically, much like living camels. Their legs were similarly adapted for a long pacing gait. 

Camelops had a diet very similar to that eaten by modern camels. They ate large amounts of shrub and leaf plants, especially brush plants. Similar tooth structure to modern camels, as well as isotopic analyses, show that they were predominantly browsing herbivores, eating tough, abrasive plants avoided by horses, deer, and bison. 

Not much is known about their behaviour, but it is supposed that, like modern camels and llamas, they travelled in herds of between two and twenty animals. They would have been found in grassland, steppe, and even tundra ecosystems and shared habitat with many other herbivore species such as bison, horses, elk, and pronghorn. They would have been preyed upon by wolves, lions, cougars, and several other predators. Modern wild camels (Camelus ferus) are also sympatric with other herbivores and have been historically preyed upon by similar animals. 

All of these similarities suggest that the modern wild Bactrian camel (Camelus ferus) should be a more than adequate ecological surrogate for the extinct western camel. They share the same dietary habits, locomotive adaptations, and may have had similar behaviour. I maintain my stance that wild camels would be an excellent way to enrich Canadian biodiversity and an equally beneficial decision for wild camel conservation. 

Part 2: Lama vs Hemiauchenia 

Not much is known genetically about the large-headed llama (Hemiauchenia macrocephala), but it has been placed in camelidae family as a very close relative of modern guanacos and vicunas. In fact these modern lamine species are thought to be descended from more ancient members of Hemiauchenia.  

The large-headed llama weighed about three hundred kilograms, making it about twice as heavy as the extant guanaco (Lama guanicoe), but still less than half the size of Camelops. It had large legs that would have allowed it to reach leaves and twigs, much like guanacos and gerenuks. It also had a large, striding gait and wide-spread toes that allowed it to cover large distances over open grasslands. It is presumed that, like modern llamas, it did not have a hump or circular foot pads found in camels.  

Like modern wild guanacos and vicunas, it would have been predominantly a browser with occasional grazing habits. Like camels it would have eaten lots of brush plants but would have had more of a focus on leaves and sedge. They had very similar tooth structure to modern lamines. 

Although presumably interfertile with the sympatric western camel (much like modern camels and llamas), the species had size differences that would have prevented them from interbreeding. North American llamas would also have shared territory with many other herbivorous species such as horses, bison, and deer. Fossil evidence shows that they were preyed upon by wolves, lions, and cougars. Modern guanacos are sympatric with other camelids and deer, and are preyed upon mostly by cougars. 

I am still considering guanacos as the best possible proxy for Hemiauchenia, their smaller size being the only truly significant difference. To help alleviate this I believe guanacos from populations with the largest animals should be used. Vicunas are still a possible option due to their superior temperature adaptability, but are not favoured because of their smaller size and more mountainous habits.  

Sources 

A complete mitochondrial genome sequence of the wild two-humped camel (Camelus bactrianus ferus): an evolutionary history of camelidae 

Genomic Data from Extinct North American Camelops Revise Camel Evolutionary History 

Stable isotopes, hypsodonty, and the paleodiet of Hemiauchenia (Mammalia: Camelidae): a morphological specialization creating ecological generalization 

Last interglacial western camel (Camelops hesternus) from eastern Beringia 

http://library.sandiegozoo.org/factsheets/_extinct/camel_extinct_western/extinctcamel.htm 

http://library.sandiegozoo.org/factsheets/_extinct/llama_extinct/llama.htm 

http://library.sandiegozoo.org/factsheets/guanaco/guanaco.htm 

Lost Giants: Large Canadian Mammals That We Cannot Replace

Elephants 

While three species (Elephas maximus, Loxodonta africana, and Loxodonta cyclotis) of elephant survive, there used to be many more across the globe, including three in Canada. These were the American mastodon (Mammut americanum), the Columbian mammoth (Mammuthus columbi), and, most famously, the woolly mammoth (Mammuthus primigenius). Elephants were, as they still are, very important keystone species that had a significant effect on vegetation. While the Americans have entertained the idea of using African and Asian elephants as proxies for these creatures, they have only done so in areas where, importantly, it does not snow. Living elephants do not have much fur, being tropical and desert-adapted creatures. This makes them decent as possible proxies for the Columbian mammoth, at least in warm places. However, even the plains of Canada are probably too cold for free roaming elephants. It might be conceivable that they be used in the warmer parts of the year and housed at others, but that is a less than favourable situation. It seems unfortunately that the only ways to get the same sort of ecological impact created by Canadian elephants are to either bring them back by cloning, modify existing elephants to be able to survive here, or to try and reproduce those effects using heavy machinery. None of these are particularly easy. I briefly entertained the idea of giving the elephants sweaters, not that it would work but how adorable would that be. 

Sloths 

There was one giant ground sloth species present across Canada, from the plains to the arctic. This was Jefferson's ground sloth (Megalonyx jefersoni), which stood about three metres tall and weighed a thousand kilograms. Like elephants, ground sloths were major environmental engineers, tearing down trees and browsing leaves. The closest living relatives of the ground sloths are the tree sloths, which are very small and in no way the ecological equivalent of their giant cousins. The Americans have discussed all sorts of animals as proxies for their ground sloth species, including rhinoceroses, anteaters, and giraffes, none of which are practical or even viable here, due to climatic restraints. It is hoped that the takins being considered as woodox proxies will also fill some of the role of the ground sloth, due to their ability to rear up on their hind legs in order to reach leaves. It is not a perfect solution, but such things are rare. 

Beavers 

Canada was also home to a creature known as the giant beaver (Castoroides ohioensis), a large rodent about the size of a black bear. Not much is known about it's behaviour, such as whether or not it built damns, and so finding an ecological proxy for it is made doubly difficult.