Zygolophodon: Cenozoic Era's Longest Tusks

In 2007, a team of paleontologists digging in Milia, in northern Greece, pulled a pair of tusks from the earth that would go on to set a Guinness World Record. Each one measured just over five meters long. They belonged to an animal that died roughly three million years ago, and to this day, nothing else ever discovered has grown tusks that long. That animal was Zygolophodon borsoni, sometimes classified under the closely related name Mammut borsoni, a member of the Mammutidae, the true mastodon family. Despite the tusks, despite the trunk, this is not a mammoth and not an elephant. Mammutidae split off from the lineage leading to modern elephants and mammoths tens of millions of years earlier, meaning its tusked, trunked appearance evolved along a completely separate branch of the family tree. Standing close to four meters at the shoulder and weighing an estimated 14 to 16 tonnes, some individuals rivaled the mass of Paraceratherium, the largest land mammal ever to exist, and outweighed several species of sauropod dinosaur entirely. Unlike the sharply curved tusks of a woolly mammoth, this animal's tusks grew nearly straight, projecting almost horizontally in front of the skull. Fossil evidence of size variation between individuals points to sexual dimorphism, suggesting males may have used their tusks in displays of dominance or in contests over mates, despite how fragile such enormous, straight structures would seem in direct combat. More likely, their sheer scale did the work on its own; a visual warning rather than a weapon. Zygolophodon was a forest dweller, an elongated-bodied browser built for stripping leaves and twigs from woodland canopy across an extraordinary range, with fossils turning up across Europe, Asia, Africa, and North America. But the Cenozoic Era's later chapters were unkind to forest specialists. As the Neogene climate cooled and grasslands began replacing woodland across much of its range, the dense forest habitat this animal depended on steadily contracted. Slowly, across the Pliocene, populations of Zygolophodon and its close mastodon relatives declined and vanished from most of Eurasia, giving ground to other proboscideans better suited to the changing world. Its record still stands today, quietly, in a museum case in Greece: the longest tusks any animal has ever grown. Subscribe for more forgotten giants of the Cenozoic Era.