Palaeoloxodon: Little and Large

An artists reconstruction of Palaeoloxodon namidicus, aka; the Asian Straight Tusked Elephant
Image Credit: Baperookamo, https://commons.wikimedia.org/wiki/File:Palaeoloxodon_namadicus-bpk.jpg

“Look, Look! It’s a Straight Tusked Elephant! No one at home will believe this!”

I may have adapted that quote from The Lord of the Rings: The Two Towers, but I like to think that Samwise Gamgee’s quote about the gargantuan Oliphant’s (or Mûmakil as they were also known) could apply to what members of our own species thought when they ventured into the depths of Central/Southeast Asia and encountered a Straight Tusked Elephant far greater and mightier than anything they had ever seen before. Meanwhile, far away on a Mediterranean island, there were Straight Tusked Elephant species far, far smaller than could ever have been imagined. Both would’ve been wonders of their respective habitats. But what exactly were Straight Tusked Elephants? And how could there be both so small and so large?

Straight Tusked Elephants were part of a Mammalian order known as the “Proboscideans”, a group of (mostly) large mammals that are represented today by African Bush Elephants, African Forest Elephants and Asian Elephants. I think everyone reading this piece will know what an Elephant looks like; a huge, quadrupedal mammal with a dexterous trunk, fearsome tusks and a vegetation diet (including grasses, leaves and woody material). But this family has a long history stretching back roughly 60 million years, and up until relatively recently it included now extinct members such as Mammoths, Mastodons and Gomphotheres. All Straight Tusked Elephants were part of the Elephant family within the Proboscidean order, rather than the Mammoth or Mastodon families, with all Straight Tusked Elephants united under the genus; Palaeoloxodon (meaning “old oblique-sided tooth”). Despite their superficially similar appearance Palaeoloxodon differed anatomically from modern elephants in a few ways. For one, they had a large crest of bone that ran across and around their foreheads like a headband. This crest provided anchoring points for large muscles that supported their heavy heads. Interestingly, these crests were not proportionally the same. A study conducted by Larramendi et. al. and published in 2020 has shown that different species and subspecies of Straight Tusked Elephants can be distinguished by the proportional size of this bony crest. Just like Mammoths, Straight Tusked Elephants are thought to have behaved similarly to Modern Elephants, right down to females and juveniles living together in herds led by a matriarch. We have evidence for this from a site in Huelva in Southwest Spain, where fossilized tracks belonging to juvenile and young adult Straight Tusked Elephants have been found together. Interestingly Neanderthal tracks are also found at this site, showing that our own species weren’t the only humans to encounter these animals! Further Neanderthal/Palaeoloxodon associations come from tools made from Palaeoloxodon bone that were discovered at Castel di Guido, a site near Rome, Italy. The site dates to 400,000 years ago; around the time when Neanderthals were living in Southern Europe, so it reasonable to think that Neanderthal hands made these tools. It is unknown whether the Neanderthals got the bones from hunting the Straight Tusked Elephants, or whether they scavenged them from a carcass, but Straight Tusked Elephants were certainly a key facet of these Neanderthals lives.

Footprints made by Straight Tusked Elephant (Palaeoloxodon antiquus) calves from Huelva in South-West Spain. These incredible trace fossils literally preserve their baby steps!
Image Credit: Carvalho et al. 2021, https://www.nature.com/articles/s41598-021-96754-1

As already mentioned, there wasn’t just one Straight Tusked Elephant. Instead, there were a grand total of seven species. The first species that we know of from the fossil record, and the first that human species encountered, was Palaeoloxodon recki, which lived roughly 3.5-1 million years ago during the Pliocene and early Pleistocene period and stood roughly 4.27 metres tall at the shoulder. This species was THE main Elephant species during its time, and was the precursor of all other Palaeoloxodon species, evolving as they spread out of Africa during migration events. Heading into Eurasia our ancestors would’ve seen the European Straight Tusked Elephant; Palaeoloxodon antiquus. This species lived across Europe and Asia, reaching as far west as the UK during the interglacial periods. These were periods of time during the Ice Age when the ice temporarily retreated, and temperatures were warmer on average. We are currently in an interglacial period right now; the Ice Age isn’t over yet! These Eurasian species of Palaeoloxodon exhibit an interesting change from their African ancestors. Palaeoloxodon recki was predominantly a grazer. However, Palaeoloxodons in Eurasia switched to a browsing diet. This switch is thought to have occurred to avoid competition with Eurasia’s other resident trunked, tusked proboscideans, the Mammoths. This difference in diet allowed Straight Tusked Elephants and Mammoths to co-exist and exploit different environmental niches. Mammoths preferred the colder grasslands of the great Mammoth steppe, whilst Straight Tusked Elephants frequented the warmer open woodlands. In the UK, Straight Tusked Elephant fossils have been found in places such as Sussex and Cambridgeshire, and they would have even roamed what’s now London! (alongside Hippos, Narrow nosed Rhinos, Lions, Terrapins and more). Fossils dating from this time have been found beneath Trafalgar Square! But how did these warm weather animals get here? At different times during the Ice Age there was a land bridge connecting the UK and rest of Western Europe. This included a land mass known as “Doggerland”, which is now submerged under the North Sea. This, combined with warmer temperatures and a riverine, open woodland habitat, meant that animals now considered to be native to sub-tropical Africa lived freely in Britain. These “African” animals co-existed with animals that still exist in smaller numbers in Europe today, such as Wolves, Deer, Bison and Bears. Other human species also lived in this world, such as Homo Heidelbergensis, and from about 400,000 years ago, the Neanderthals. So, in this very recent geological past, the UK was once an extremely biodiverse landscape, with Straight Tusked Elephants being its mightiest residents.

A map showing the distribution of the European Straight Tusked Elephant (Palaeoloxodon antiquus). The dots represents sites where their fossils have been found.
Image Credit: DagdaMor, https://commons.wikimedia.org/wiki/File:Palaeoloxodon_antiquus_map.png

As Homo sapiens migrated into Europe, they also spread further east into Asia. As they reached India, China and Southeast Asia they would’ve encountered the spectacular Asian Straight Tusked Elephant, Palaeoloxodon namidicus. Now, Palaeoloxodon species had been big before, but Palaeoloxodon namidicus was in a different league altogether. Estimates have suggested that it could have attained a mighty 4.5-5 metres at the shoulder and weighed between 14 and 22 tons! This makes it not only the largest Palaeoloxodon, but possibly the largest animal to have walked the planet since the extinction of the non-avian dinosaurs! No other land mammal has matched it (though the older, hornless, giraffe like rhino Paraceratherium came close). This sheer size along with herding behavior (in females and adolescents) and likely bad temperament (especially during “musth”, which is when bull elephants are in a highly aggressive state due to looking to fight other males for the right to mate) would’ve protected it from any hunter. Even humans, the planets most destructive predators with our big pointy sticks and intelligence, might’ve thought better than to take on a full-grown adult. P.namidicus’ sheer size would’ve made them the most dangerous animal that our species has ever encountered. This is really something considering the other dangerous animals we’ve encountered throughout our history, such as Short Faced Bears, huge Monitor Lizards, Sabre-Tooth Cats, Giant Ground Sloths and more (not to mention modern day animals such as Lions, Sharks, Hippos, Buffalos, Crocodiles and, well, other Elephants!). P.namidicus is thought to have gone extinct roughly 22,000, years ago. However, if a controversial study published by Li et. al. in 2012, which studied ancient man-made Elephant statues with weird, twin lipped trunks, and preserved teeth is to be believed (and it really needs to be taken with a grain of salt), they or a similar species may have existed in Northern China as recently as 3,000 years ago! It really was the closest thing to the Mûmakil of Tolkein’s epic!

A size comparison between a human, Palaeoloxodon namidicus (right) and Paraceratherium (left). The material we have for Palaeoloxodon namidicus is fragmentary (only the partial femur shown in its silhouette) but upper size estimations from these indicate that it may have been the largest ever land mammal.
Image Credit: Larramendi, A. 2015, https://www.app.pan.pl/article/item/app001362014.html

Meanwhile on the other side of the Eurasian landmass, tucked away within the Mediterranean, we had Straight Tusked Elephants that were an awful lot smaller, (and a lot less dangerous), than the titans that roamed Asia. On the Mediterranean islands of Malta, Cyprus, Crete, Sicily and more, there lived two dwarf species of Straight Tusked Elephant: Palaeoloxodon falconeri and Palaeoloxodon cypriotes. P.cypriotes was about as tall as a person, (which is small enough for an Elephant), however P.falconeri was even smaller, only as big as a sheep! The reason these Straight Tusked Elephants were so small was due to their island homes. On islands, there is a trend for evolution to favour the smaller individuals within large species as they are better adapted to cope with the lack of food and living space. Smaller animals need less food; therefore, they are more likely to survive, reproduce and pass on their diminutive size to their offspring. So, over thousands to millions of years, the ancestors of these dwarf elephants (most likely a population of Palaeoloxodon antiquus that had made their way to the islands when sea levels were lower) steadily shrunk and became genetically different enough to become a new species. Despite their small size these Straight Tusked Elephants shared similar behaviors with their larger cousins, browsing on the island’s vegetation, females and young living in herds and bulls roaming alone. But while these Palaeoloxodon were smaller, some other island residents grew larger. This can create some very amusing scenarios. For example, alongside the dwarf elephants on Malta and Sicily there was also a species of giant swan (Cygnus falconeri) that grew to a whopping 2 metres long from bill to tail (reaching an average person’s shoulder!), had a wingspan of 3 metres and weighed 26 kilograms. This meant that it was taller than P.falconeri! On Malta, the Swans dwarfed the Elephants!

A skeleton of a Dwarf Sicilian Elephant (Palaeoloxodon falconeri). It has been suggested by some that the bones of Elephants found within the Mediterranean and in Southern Europe may have partially inspired the myths of Cyclops. Their skulls, as seen in this skeleton, do have a hole in the middle that could be mistaken for a single large eye socket. In life it was the nasal cavity at the base of the trunk.
Image Credit: James St. John, https://www.flickr.com/photos/jsjgeology/32552806631/

The Straight Tusked Elephant lineage was incredibly successful, spanning across Africa and Eurasia, from the UK and Spain to Japan (where the species Palaeoloxodon naumanni lived). They evolved varying body sizes, diets and appearances as a response to the environments they found themselves in. This enabled them to cope with whatever they encountered. That is; as long as it wasn’t too cold and there was plenty of their preferred open woodland. However, despite this, their preferences would contribute to their end. The last of the lineage would go extinct roughly 21,000 years ago, near to the end of the last ice age. It is thought (like a lot of other megafauna) that their extinction was linked to dramatic climate changes and human hunting. The changing climate reduced the preferred forested habitats of these Elephants in favour of less suitable expansive dry grasslands. Meanwhile those efficient, ruthless humans may have put further pressure on populations, with some sites in Southern and Central Europe showing human butchering of Straight Tusked Elephants. Young, old and injured Elephants would’ve been most at risk, and while a full grown P.namidicus might have been safe, other Straight Tusked Elephants may not have had the same luxury.

It’s a shame that they never made it into recorded history. Palaeloxodon falconeri’s bizarrely small size would’ve made it an internet sensation, while a full grown Palaeoloxodon namidicus would’ve made for an incredible war elephant!

References/Further Reading

Larramendi et. al. 2020. Study that looked traced the evolution of Palaeoloxodon skulls, and what this tells us about the different Straight Tusked Elephant species.

Asier Larramendi, Hanwen Zhang, Maria Rita Palombo, Marco P. Ferretti, The evolution of Palaeoloxodon skull structure: Disentangling phylogenetic, sexually dimorphic, ontogenetic, and allometric morphological signals, Quaternary Science Reviews, Volume 229, 2020, 106090, ISSN 0277-3791, https://doi.org/10.1016/j.quascirev.2019.106090.

An article written by Josh Davis and published on the Natural History Museum website about Palaeoloxodon and the study by Larramendi et. al. on on the variation of their headband like bony crests.

Davis, Josh “Weird skulls of straight-tusked elephants reveal just how many species there were”, Natural History Museum, www.nhm.ac.uk, 18th February, 2020, https://www.nhm.ac.uk/discover/news/2020/february/weird-skulls-of-straight-tusked-elephants-reveal-how-many-species.html

Neto de Carvalho et. al. 2021 paper describing the fossilized trackways at Huelva, which included the tracks of young and young adult Palaeoloxodon, Neanderthals and other animals

Neto de Carvalho, C., Belaústegui, Z., Toscano, A. et al. First tracks of newborn straight-tusked elephants (Palaeoloxodon antiquus). Sci Rep 11, 17311 (2021). https://doi.org/10.1038/s41598-021-96754-1

Villa et. al. 2021 paper studying the Palaeoloxodon bone tools, likely made by Neanderthals, from Castel di Guido in Italy

Villa P, Boschian G, Pollarolo L, Saccà D, Marra F, et al. (2021) Elephant bones for the Middle Pleistocene toolmaker. PLOS ONE 16(8): e0256090. https://doi.org/10.1371/journal.pone.0256090