When I was a small child, it was traditional in rural Ireland to go round neighbouring churches and view their nativity cribs. The ones I was always more impressed by were the ones with huge plaster animals – the oxen, donkey, sheep, and tiny lambs in shepherds’ arms. One church outshone all of them. It had a set of life-sized plaster camels, decked in tassels and saddles, resting from the Magi’s long ride across the Levant. At five, that makes a pretty big impression on you. So, if I’m honest about it, I’ve been a fan of camels ever since. Love their attitude and endurance, and I do find them immensely beautiful creatures when you get up close – oh those big fluttery eyelashes!

Those plaster camels, and the subsequent real ones I’ve cantered across the sands of Egypt, Sudan and Tunisia would be dwarfed by the biggest camel of them all, an early Twilight Beast, Gigantocamelus spatulus. This early Pleistocene giant lumbered across the plains of North America up until about 300,000 years ago, although details are sketchy on that date at best. Single humped, at a height of over 3.5 metres, about 4 m in length and weighing up to 2500 kg, these were true megafauna similar in size to the familiar Woolly Mammoth.

Gigantocamelus was just what the name suggests: a giant camel. Image by Roberto Diaz Sibaja

The evolution of Gigantocamelus straddles the late Pliocene era (around 4 million years ago) and the early climate fluctuations in North America, from the Nebraskan glacial phase around 700,000 BP to the warmer Yarmouth phase, around 300,000 BP. Because of the species’ survival through these early fluctuations of temperature, it’s likely these camels had thick, warm coats– think giant fluffy critters with a whole lot of ‘tude out on the openness of the great grass plains of pre-Ice Age landscapes.

What we can tell from bone deposits in Nebraska is that there was considerable sexual dimorphism in these perhaps-not-so-gentle-giants. The females were about 20% smaller than the males, which had rather large canines most likely used in rutting battles. (One journal suggests they were about the same size as a small Tyrannosaurus rex tooth!) They travelled in herds and they travelled fast – way out in the desert lands of Santa Fe, preserved hoof prints show an animal which was no slouch with speed.

The enormous head of Gigantocamelus from the Upper Pliocene/Lower Pliocene, Garden Co., Nebraska, fossil. Those enormous canines are similar in size to the teeth of Tyrannosaurus rex! Photo © Phil Degginger

So, if you will, imagine we are walking across an early Pleistocene plain, somewhere in New Mexico, perhaps. We have our cameras (we brought them in our TARDIS) and hiking boots on. The air is cool, the grassland an ocean of earthy green. We catch sight  of a herd of G. spatulus grazing, but they’ve caught sight of us too – suddenly there’s a mob of irate,  3.5m (12ft) high camels, weighing in at over a ton each, snorting their rage (because even giant camels have short fuses) while running rapidly for us, fangs bared. Sorry, gentle reader, but it’s every man and woman for themselves on this one!

While we all acknowledge that nature is red in tooth and claw, so are palaeontologists when it comes to nomenclature and taxonomies. There’s been a somewhat prolonged discussion about whether the equally massive camel Titanotylopus and our friend Gigantocamelus were really the same critter. The first Gigantocamelus were discovered at the end of the 19^th century, and categorised into a genus in the 1930s. But, palaeontologists (just like archaeologists) love a good decades long ‘debate’. It’s really not so long ago that it was finally decided they were actually two very similar, but different camels. This was all based on those teeth. Gigantocamelus’s teeth were hypsodontic, meaning that its long teeth had enamel beyond the gum line to allow for wear and tear while eating rough and gritty vegetation, very similar to grazing of horses and cattle. Now, before anyone jumps to the conclusion of climate=grasslands=hypsodontic evolution, don’t. Stop right there! That theory was tested and it looks as though these grazing animals just need a little grit in their bellies. This actually has a name; the ‘Grit, Not Grass Hypothesis’. Sometimes, I swear, I love palaeontology and palaeoenvironmentalism!

These giant camel genera developed through the late Pliocene some 4 million years ago. Grasslands flourished at this time, although just as the Pliocene was reaching its end, ice caps in Greenland were getting bigger, and glaciation events were waiting in the wings to start changing the face of the earth as it was known. The Pleistocene Big Freeze was arriving, with all the associated changes….

The extent of the glaciers in Northern America. Image © Encyclopaedia Brittanica

Although they survived for over 2 million years from the late Pliocene into the Pleistocene, this hugely variable Epoch may have the beginning of the end of the giant camels of North America.  This is one of the rare extinctions in which humans almost certainly had no part. The Kansan glacial event, which pretty much coincides with the UK’s Anglian equivalent, around 480,000 to 230,000 BP. While the regions of North America inhabited by the giant camels – Nebraska, New Mexico, Kansas and others – were not covered in ice, vegetation would have been likely depleted due to the changes in climate. Very recent research has shown that Gigantocamelus was a leaf browser, but most likely of smaller shrubs and bushes, in keeping with those long teeth. All it would take would be one prime species of shrub or bush to decline and populations would suffer. There again, we are currently witnessing the decimation of the Saiga, due to bacterial imbalances, possibly caused by a lethal combination of pollutants and climate change. Populations could have been on the slide from the climate shifts at the end of the Pliocene into the Pleistocene. There’s simply insufficient evidence to offer conclusive reasons as to what brought the reign of the giant camel to an end, yet allowed their smaller cousins to continue for another 200,000 years.

To the best of our knowledge, humans never got to witness these creatures; there are no petroglyphs carved on cavern walls, no images painted in ochre – in fairness, we aren’t even quite sure when they become extinct, the date of around 300,000 being an estimate simply because no later bone assemblages have been found – yet. That caveat of ‘yet’ being the thing each scholar of the past literally lives for. Most fossils have been found around the Lisco bone beds of Nebraska, with a few at Clovis and El Paso, New Mexico, and these particular specimens have been presumed to date to the middle of the Pleistocene. It may be that the mighty camels survived later into the Pleistocene. The truth, as they used to say in the 90s, is out there!

So, as the Festive Season is almost upon us I’m going to re- imagine those cribs of childhood, only with a menagerie of Twilight Beasts. Magi on Gigantocamelus, shepherds with Myotragus tucked under their arms and Hippidion instead of donkeys, side by side with sleepy aurochs. It’s a stretch of imagination (and almost certainly heresy) to suggest the angels in attendance– perhaps one called Jan, another Ross and… well, I might need some R and R from writing to flap my wings and keep an eye on all those animals!

From me, to you, whatever way you celebrate this winter holiday, have a wonderful one – keep safe, be kind, and we shall look forward to finding more wonderful creatures for you in 2016. Peace.

Written by Rena Maguire (@JustRena)

Further Reading:

Breyer, J. (1976). ‘Titanotylopus (= Gigantocamelus) from the Great Plains Cenozoic.’ Journal of Paleontology. 50 (5). pp 783-788. [Full article]

Farmer, G. T., & Cook, J. (2013). ‘Pleistocene glaciations’. In Climate Change Science: A Modern Synthesis Springer Netherlands.  pp 407-427. [Book]

Harrison, J. (1985). ‘Giant camels from the Cenezoic of North America.’ Smithsonian Contribrutions to Paleobiology. [Full article]

Jardine, P.E., et al. (2012). ‘Grit not grass: Concordant patterns of early origin of hypsodonty in Great Plains ungulates and Glires’. Palaeogeography, Palaeoclimatology, Palaeoecology. 365-366. pp1-10. [Abstract only]

Kukla, G. (1978).  ‘The classical European glacial stages: correlation with deep-sea sediments’ University of Nerbraska – Lincoln. [Full article]

Mendoza, M. & Palmqvist, P. (2008).  ‘Hypsodonty in ungulates: an adaptation for grass consumption or for foraging in open habitat?” Journal of Zoology 274 .2: pp.134–142. [Abstract only]

Railsback, L. B., et al. (2015). ‘An optimized scheme of lettered marine isotope substages for the last 1.0 million years, and the climatostratigraphic nature of isotope stages and substages’. Quaternary Science Reviews.111: 94-106. [Full article]

Rybczynski, N., et al. (2013). ‘Mid-Pliocene warm-period deposits in the High Arctic yield insight into camel evolution’. Nature communications. 4. pp.1550. [Full article]

Semprebon, G & Rivals, F. 2(010). ‘Trends in the paleodietary habits of fossil camels from the Tertiary and Quaternary of North America’ Palaeogeography, Palaeoclimatology, Palaeoecology, 295. pp 131-145. [Full article]

Strömberg, C.E. (2006). ‘Evolution of hypsodonty in equids: testing a hypothesis of adaptation.’ Paleobiology. 32:  pp 236–258. [Full article]

Thompson, M. E., White, R. S., & Morgan, G. S. (2007). ‘Pace versus trot: can medium speed gait be determined from fossil trackways.’ In Spielmann L and Lockley MG (eds), Cenozoic Vertebrate Tracks and Traces. New Mexico Museum of Natural History and Science, Bulletin, 42: pp 309-314.

Tucker, S. T., et al. (2014). ‘The geology and paleontology of Ashfall Fossil Beds, a late Miocene (Clarendonian) mass-death assemblage, Antelope County and adjacent Knox County, Nebraska, USA’. Field Guides. 36:  pp 1-22. [Abstract only]

Warnica, J. M. (1966). ‘New discoveries at the Clovis site’. American Antiquity. pp 345-357.

Waters, M. R., et al. (2015). ‘Late Pleistocene horse and camel hunting at the southern margin of the ice-free corridor: Reassessing the age of Wally’s Beach, Canada. Proceedings of the National Academy of Sciences, 112.14: pp 4263-4267. [Full article]