Meet Long Tusk

Some of you may have been lucky enough to see these incredible animals in the wild. Others may have felt a strong tug at your heart seeing one in a zoo. Most, if not all, of us have seen these magnificent creatures on amazing wildlife documentaries. And these are truly magnificent animals. Elephants are the heaviest land animals on the planet: weighing as much as five cars (yes, five cars!), the African elephant is the heaviest land animal on the planet!

When I see these enormous thick skinned, wrinkly mammals, I can easily imagine being face to face with a prehistoric animal. These are real survivors: with fossils of the ancestors of today’s elephants dating all the way back to the Pliocene. Elephants are the last of the true mega-fauna.

A beautiful Asian Elephant (Image by Yathin S Krishnappa, Public Domain)

A beautiful Asian Elephant (Image by Yathin Krishnappa, Public Domain)

There is a surprising amount of variety in these giants. There are two species of African elephants: Loxodonta africana (the African Bush Elephant) and Loxodonta cyclotis (the African Forest Elephant). As for their cousins, the Asian Elephant (easy to identify because of their smaller ears compared to the African elephant), there are three sub-species: Elephas maximus maximus; E. m. indicus; and E. m. sumatranus. Contrary to most of the wildlife documentaries showing elephants slowly trundling across the harsh, dry savannah, they are at home in some funkily diverse environments: savannah, deserts, forests, marshes, and even mountains. You would think big animals would be specialists suited to a particular environment. But elephants, it turns out, are fairly adaptable giants.

All elephants alive today belong to the Family Elephantidae. This Family is the last one surviving within the Order Proboscidea: since their origins around 30 million years ago, the other 9 proboscidean Families (with a whopping 177 species) are extinct. What survives today is just the trimmings of a once hugely diverse group of truly wonderful animals.

The variety of proboscideans (Artworks by Vladimir Nikolov. Editing and digital work by Docho Dochev.)

The variety of proboscideans since their origins around 60 million years ago. (Artworks by Vladimir Nikolov. Editing and digital work by Docho Dochev. Image from here)

And what a diverse group it was. There were giants, such as the enormous Steppe Mammoth and the Columbian Mammoth. There were pygmy mammoths off the coast of California and dwarf elephants living on Mediterranean Islands, as well as dwarf Stegodons on Flores. And some species in this Order were just weird, like Gomphotheres with their shovel-like mouths, and the gigantic Deinotherium with it’s downward facing tusks. There was one Pliocene proboscidean that had the longest tusks of any creature to have ever lived, and may have even rivalled Deinotherium in size.

Many proboscideans originated in Africa with some species spreading fairly quickly across the northern hemisphere. Perhaps one of the most successful was Zygolophodon (or, for a more informal name ‘Long Tusk’ for reasons you will see in a moment). Fossils of this incredible creature have been discovered in Northern and Southern America, Asia, Russia, and Europe.

Meet Long Tusk. One of the largest land mammals, possibly boasting the largest tusks of any animal. Rey is dwarfed by it's size. (Image by Jan Freedman)

Meet Long Tusk. One of the largest land mammals, possibly boasting the largest tusks of any animal. Rey is dwarfed by it’s size. (Image by Jan Freedman)

The more robust teeth are the most frequent fossils of Zygolophodon, but some skulls have been found. And some tusks too. Some pretty enormous tusks. Lying down, the length of my body would not be as long as half the length of a tusk: hence my name for this giant. Not as curved as elephants alive today, or mammoths, we don’t really know why Long Tusk had such long tusks. There is evidence of sexual dimorphism Zygolophodon. Hard, bumpy teeth from France and America show size differences indicating that there were differences between the size of males and females. And looking at today’s elephants (along with good fossils of Woolly Mammoths, Mastodons and others) the males were larger than the females. Perhaps male Zyglophodon challenged other males over females. Although I find the clashing of such long, and frightfully delicate tusks impossible. Such a length would make them ever so easy to snap. Perhaps the sheer size was enough. One look and others knew.

Two enormous tusks found in Greece

Two enormous tusks of Zygolophodon tapiroides found in Greece (Image Public Domain)

Zygolophodon belongs to the Family of proboscideans called the Mammutidae, which includes the familiar American Mastodon. Despite the name, the Mammutidae doesn’t include the Woolly Mammoths: these shaggy beasts are in the same family as elephants. Some researchers think that the American Mastodon was the descendent of Zygolophodon. The teeth pattern, and tusk shape are similar; just a scaled down version.

All over the world, at the end of the Pliocene our enormous tusked proboscidean vanished. Other species were coming out of Africa from the middle Miocene to Pliocene, and these may have been an extra competitor. Changes in the climate may have been a contributor, as the world was beginning to cool at the end of the Pliocene resulting in changing vegetation patterns.

We may never know what happened to Long Tusk. What we do know is that they were just one small Family in perhaps the most spectacular Orders of mammals. Today, just a handful of proboscideans are with us. From Africa to India, the elephants are all that remain. We need to make sure that this incredible group doesn’t vanish forever.

Written by Jan Freedman (@JanFreedman)

Further Reading:

Cooper, L. N., et al. (2014). “Anthracobunids from the Middle Eocene of India and Pakistan Are Stem Perissodactyls”. PLoS ONE 9 (10): e109232 [Full article]

Gheerbrant, E. (2009). ‘Paleocene emergence of elephant relatives and teh rapid radiation of African ungulates’. Proceedings of the National Academy of Sciences. 106 (26): pp.10717–10721. [Full article]

Larramendi, A. (2005). ‘Shoulder height, body mass and shape of poboscideans’, Acta Palaeontologica Polonica 60. [Full article]

Lofgren, D. L., & Rajsavis, A. (2011). ‘Partial skull of Zygolophodon (Mammalia, Proboscidae) from the Barstow Formation of California’. Journal of Vertebrate Paleontology. 31: 6. Pp.1392-1396. [Abstract only]

Madden, C. T. (1980). ‘Zygolophodon from Subsaharan Africa, with observations on thE systematics of Paleomastodontid Proboscideans’. Journal of Paleontology.54:1. pp.57-64.

Sanders, W. J. & Miller, E. R. (2002). ‘New Proboscideans from the Early Miocene of Wadi Moghara, Egypt’. Journal of Vertebrate Paleontology. 22:2. pp.388-404. [Full article]

Shoshani, J., & Tassy, P. (2005). ‘Advances in proboscidean taxonomy & classification, anatomy & physiology, and ecology & behavior.’ Quaternary International. 126-128. pp.5-20. [Abstract only]

Shoshani, J., et al. (2006). ‘A proboscidean from the late Oligocene of Eritrea, a “missing link” between early Elephantiformes and Elephantimorpha, and biogeographic implications’. PNAS 103 (46). [Abstract only]

Vergiev, S. & Markov, G. (2010). ‘A mandible of Deinotherium (Mammalia – Proboscidea) from Aksakovo near Varna, Northeast Bulgaria’. Palaeodiversity 3: pp.241–247. [Full article]

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One Response to Meet Long Tusk

  1. Pingback: Morsels For The Mind – 06/05/2016 › Six Incredible Things Before Breakfast

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