Now that my thesis is nearly at the end, I can tell you all this secret. I have been so tiddled off at the archaeological paradigm that all ancient horses were wee tiny ponies. Victorian zoologists like Ridgeway and Ewart made up stuff about types, which certainly were not formalised breeds, linking everything they liked, and very much approved of, to the exquisite Arabian horse, and sometimes they made up a whole new species for themselves (like Equus caballus celticus – a totally tiny Celtic pony!) because it seemed like a good idea at the time. However, they were two smart cookies for their time, so I will forgive them, as any horsie person knows, horses get under your skin somewhat, and if we can imagine unicorns, we can imagine special Celtic ponies!

However, way out east in the Iron Age, horses were horses, with the ‘fossil’ breed of the Akhal Teke, and the bigger cold bloods, as they call them in equestrian circles. Now, don’t get me wrong – there were indeed very little ponies in the past. Insular breeds, such as the British Exmoor and Scottish Eriskay, tend to be small, and humans across Europe and Eurasia bred the wildness out of the true wild horse, the Tarpan, making the overall size of equids smaller and narrower and presumably easier to control. The now-extinct Lofoten island pony was likely the ancestor of the real Shetland pony, the ones which haven’t been bred up with new bloodlines chucked in every now and then. The Lofoten was a very small, hairy pony breed, like a pure white teddy bear, which came to a rather instant extinction, when the very last one was shot deliberately in 1897 to preserve its body for science. I know, right?  The poor little thing has been on display since then, in Bergen Museum.

The last of his line – the Lofoten pony, which was made extinct to be a museum piece – Victorians, eh! ( image from Ridgeway 1905)

Nature, however, loves diversity – life forms adapt and grow, or shrink depending on a whole host of environmental factors. If you went back to the Pleistocene, you’d find lots of wild equids of all sizes and all shapes….Equus alaskae, E. nevadanus, E. taeniopus… the list is massive. But among them, there was a giant, possibly bigger than a Clydesdale –  Equus giganteus. There are some pretty large gaps of knowledge about E. giganteus, because most of the evidence is based on just teeth. There was supposedly also a full mandible or skull found by ‘Mister Bones’, the 19th century fossil hunter Barnum Brown.

The early days of fossil collecting was often met with a flurry of new species. With just a few fragments to go on, later palaeontologists have since noticed that many fossils of ‘new species’ actually all belong to just one species. There’s confusion over whether the fossils of  E. pacificus might be a variation of E. giganteus, and there might even be a larger horse,  E. enormis, although there is even less evidence for it, being confined to some West Coast USA fossils detailed in Murray’s 2008 thesis. They’ve been primarily found where there were Pleistocene prairies – Texas, Kansas, Oklahoma, California and Nevada. Imagine how stunning it would have been to watch herds of these creatures grazing and galloping. Mind you, with their considerable size, they would need a fair bit of space to gallop wild and free.

Now, we measure horses at the withers – the little lump at the base of the neck, not the tops of their heads and we call it hand high, usually abbreviated to hh. E. giganteus likely measured over 20 hands, or 2m (6’7”), as simply, we don’t even know if the few scant remains of teeth we have are from juvenile specimens. (Estimates on total height are 10 feet!) However, we know enough to speculate on  E. giganteus to make it a creature of a Tolkeinesque dreamtime, bigger than a Shire Horse, and weighing in between 700 and 1600 kg depending on which reconstruction model you choose to go with (palaeontology is, in this respect, every bit as bad as archaeology- everything has a ‘but what if’ added!).  Much good, solid horse sense was written on this by Gidley in 1901, who stated that the superior molar tooth found in Texas in the 19^th century was bigger by over a third of the diameter than that of an equivalent modern draft horse.

The ginormous size of the North America giant horse, Equus giganteus.

While we can pretty much reconstruct the big, dignified head of E. pacificus, another giant Pleistocene horse of the Wild, Wild West, we cannot yet do so for E. giganteus. But we can make some pretty good guesses. So-called ‘primitive’ types and breeds usually have certain distinctive markings, fingerprints from the deep past, carried on shoulders and soft muzzles to remind us of their ancestors, who existed before humans domesticated them. Have a look at the Przewalski horse, with its big solid head, so like cave drawings of Chauvet, or the Dulmen from Germany, or the wee English Exmoor. They have what we call a ‘mealy muzzle’, in that their soft noses are often paler than their coat colouring while their hocks, or lower legs , are darker. Across their withers, running down their backs, is a dark line of hair called a dorsal stripe, although I think of it as a time line, proudly stating the ancient ancestry of the breed. On occasions, with very old breeds, you may even get a hint of stripes on the lower limbs. I’d suspect that Equus giganteus had all of the above, loud and proud. They do say everything is bigger in Texas!

Our giant horses were present in the great Pleistocene grasslands of the western USA, but probably took their first leggy steps in the Pliocene, around 2.5 million years ago. Horses are believed to have evolved in the North American continent, moving into South America about 1.5 million years ago. All American species of wild equids became extinct by 10,000 years ago, and the prairies and grasslands were empty of neighs and thundering hooves until the reintroduction of Equus caballus by the Spanish conquistadores of the 1500’s. Some of their horses escaped and reclaimed the land as mustangs, the iconic feral mixed-breed types. But they were, and are, normal-sized horses, unlike the big beauty of E. giganteus.

A friend of mine, Maximus, a fjord pony, who happens to be showing off his  ancient ancestry rather well, with his lovely mealy muzzle and hog mane (he’d like to be your friend too if you head up Armoy direction)

So, what brought the reign of these giant, wild spirits of the grasslands to an end? And when exactly did it happen? The truth is, we really don’t know yet. Regular readers will know that there were huge climate changes occurring during the Pleistocene, which were responsible for some of the megafaunal extinctions. The climate shift resulted in vegetation changes, from higher protein plants ( known as C3 vegetation) to coarser, harder to digest grasses ( known as C4 grasses) resulted in the grasslands being incapable of sustaining many megafaunal species.This is usually considered the reason for  extinctions of smaller horses of the Americas, and it may be that E giganteus  left the land earlier. After all, there was a whole lot of horse to feed.

However, the time we estimate the great horses vanished coincides with the arrival of the Clovis people in North America, probably around 13,000 years ago. Clovis points, the lethally sharp lithics used by these ancient people have been found in Texas although, so it is anyone’s guess as to whether the horses were hunted into extinction. We know humans hunted horses in Europe, so while there is no definite early  evidence yet, it wouldn’t be so surprising if a future excavation in the southwest states turns up something more conclusive than ‘maybe’.  An indirect possibility is that fires caused by humans could well have destroyed much of the original grasslands. Remember, with large numbers of herbivores on such grasslands, you tend to get predators too, and they will be quite happy to pick off an unwary human as much as any other smaller creature on the prairie.Short-sighted solutions of slash and burn may have hastened the end of our lovely horse.

So, we have no idea when Equus giganteus became extinct. Recently, in the name of research, I had the chance to gallop out on a Clydesdale, which is still smaller than E. giganteus. Her name was Niňa, which, meaning little girl, was a bit of a joke. She was huge. I’m an experienced horsewoman, but galloping her felt as if I were strapped to the outer engine of an aircraft taking off, like straddling thunder.  While all wild horses are enchanting, triggering something deep inside us as humans, I can’t help thinking of  what perhaps dozens or hundreds of horses, well over 20 hh, would be like – storm-clouds made flesh, whinnying and snorting across the grasslands. What I’d give for a TARDIS ( and probably a saddle and bridle) !

Written by Rena Maguire (@JustRena)

Further reading:

Baskin, J. A., 1991. ‘Early Pliocene horses from late Pleistocene fluvial deposits, Gulf Coastal Plain, South Texas’.  Journal of Paleontology. 65. pp. 995-1006. [Abstract only]

Cantalapiedra, J.L., Prado, J.L., Fernández, M.H. and Alberdi, M.T., 2017. Decoupled ecomorphological evolution and diversification in Neogene-Quaternary horses. Science, 355(6325), pp.627-630. [Full article]

Cope, E. D., 1891. ‘On a skull of Equus excelsus Leidy, from the Equus beds of Texas’ American Naturalist. 25. pp 912-913.

Cope, E. D., 1885 ‘Pliocene horses of southwestern Texas’  American Naturalist. 19. pp1208-1209.

Dalquest, W.W., 1977. ‘Mammals of the Holloman local fauna, Pleistocene of Oklahoma’. The Southwestern Naturalist, pp.255-268. [Full article]

Dingus, L and Norel. M 2010. Barnum Brown; the man who discovered Tyrannosaurus Rex. Berkley: University of California Press

Eisenman, V. n.d Giant Horses. (Full article)

Gidley. J.  1901. Tooth Characters and Revision of the North American Species of the Genus Equus. Bulletin of the American Museum of Natural History 14(9):1-60. [Full article]

Grayson, D.K. and Meltzer, D.J. 2003. ‘A requiem for North American overkill’. Journal of Archaeological Science, 30(5), pp.585-593. [Full article]

Haynes, G., 2014. ‘North American Megafauna Extinction: Climate or Overhunting?’. In Encyclopedia of Global Archaeology  New York: Springer. pp. 5382-5390. [Abstract only]

Hill ME, Hill MG and Widga CC. 2008. L’ate Quaternary bison diminution on the Great Plains of North America: Evaluating the role of human hunting versus climate change’. Quaternary Science Reviews 27(17-18). pp 1752-1771. [Full article]

Lambert WD and Holling CS. 1998. ‘Causes of ecosystem transformation at the end of the Pleistocene: evidence from mammal body-mass distributions’. Ecosystems 1(2) pp 157-175. [Abstract only]

Lyons RK and Hanselka CW ‘Grazing and browsing: how plants are affected’. Texas Cooperative Extension. Texas A&M University System. [Full article]

Murray, L. K. 2008. Effects of taxonomic and locality inaccuracies on biostratigraphy and biochronology of the Hueso and Tapiado formations in the Vallecito Creek–Fish Creek Section, Anza-Borrego Desert, California. PhD Dissertation, University of Texas at Austin, pp. i-xxiii, 1-532. [Full dissertation]

Owensby CE. 1998. ‘Role of grasslands as modifiers of global climate change’. Proc. 18th International Grassland Congress. pp 9-12 [Full article]

Ridgeway, W. 1905. The Origin and Influence of the Thoroughbred Horse. Lofoten pony reference  pp 119-121.  [Full article]

Stromberg MR, D’Antonio CM, Young TP, Wirka J, Kephart PR. 2007. ‘California grassland restoration’. in: Stromberg MR, Corbin JD and D’Antonio CM(eds) California grasslands: Ecology and management. Berkeley, Los Angeles, London: University of California Press. pp 254-280. [Book]