The Dwarf Elephants of Sicily and the Cyclops Myth

In the mid-20th century, excavators in Spinagallo Cave, near Syracuse in southeast Sicily, dug out the bones of more than 100 tiny elephants: adults, juveniles and newborns. Modern body-mass estimates put a full-grown male at roughly 250–300 kilograms and about a metre at the shoulder. A newborn weighed around 7 kilograms, about as much as a human baby at a few months old.

These were the dwarf elephants of Sicily. Their ancestor, the straight-tusked elephant, was one of the largest land mammals of the Ice Age. Long before anyone wrote of one-eyed giants, the Mediterranean islands were home to real animals as strange as any myth.

How the dwarf elephants of Sicily shrank

The mainland straight-tusked elephant, Palaeoloxodon antiquus, stood up to about four metres at the shoulder and could weigh more than 10 tonnes. During periods of low sea level, some reached Sicily, probably by swimming short gaps. Elephants are strong swimmers, and the sea between Sicily and mainland Italy is narrow.

On the island, their descendants shrank dramatically. Palaeoloxodon falconeri, named after the 19th-century palaeontologist Hugh Falconer, lived in the Middle Pleistocene, several hundred thousand years ago. Adult males were about 1 metre tall and females about 80 centimetres, according to reconstructions by Asier Larramendi and Maria Rita Palombo. That is only a few percent of the ancestor's body mass, one of the most extreme size reductions known in mammals.

Shrinking was not uniform. Brain size usually falls more slowly than body size, so island dwarfs end up with relatively large brains for their bodies, and Larramendi and Palombo's calculations for the Spinagallo sample show exactly that. The skeletons also show that this was a breeding population, not a few stray animals: the cave holds newborns, juveniles and old adults together.

Later, a second, larger dwarf, Palaeoloxodon mnaidriensis, replaced P. falconeri on Sicily. It was still well below mainland size. Secure evidence for people on Sicily appears only in the late Ice Age, long after P. falconeri had disappeared, so no human ever saw one alive.

Why island animals shrink

In 1964, the zoologist J. Bristol Foster noticed a pattern in island mammals. Large species such as deer and elephants tend to get smaller on islands, while small species such as rodents tend to get bigger. Biologists now call this the island rule.

Several pressures work together:

• Limited food. A small island cannot feed many large animals, and smaller bodies need less.
• Few predators. Large size protects against lions and wolves. Without them, the cost of a big body stops paying off.
• Faster breeding. Smaller animals usually mature and reproduce earlier, which helps on unstable islands.

The same process produced the dwarf Stegodon of Flores, which shared its island with Homo floresiensis (see the strange animals of Flores). Whether island dwarfing also shaped the hobbit itself is debated, a question covered in Homo floresiensis vs Homo erectus.

Dwarf elephants were not limited to Sicily. Malta's Għar Dalam cave holds bones of dwarf elephants and dwarf hippos. Crete had a dwarf mammoth, Mammuthus creticus, which Victoria Herridge and Adrian Lister showed in 2012 to be a true mammoth rather than a straight-tusked elephant. Cyprus had both a dwarf elephant and a pygmy hippo.

The Cyclops connection

An elephant skull has a single large opening in the centre of the face. It is the nasal cavity, where the trunk attached. The eye sockets sit at the sides and are easy to miss. To someone who had never seen a living elephant, that central hole looks like the socket for one huge eye, set in a skull far bigger than a human's.

In 1914 the Austrian palaeontologist Othenio Abel proposed that ancient Greeks who found such skulls imagined a race of one-eyed giants, the Cyclopes. In Homer's Odyssey, Odysseus blinds the Cyclops Polyphemus. Later Greek writers linked the Cyclopes to Sicily. The historian Thucydides, in the 5th century BC, mentions them among the island's earliest legendary inhabitants, and tradition placed Polyphemus near Mount Etna.

Abel's argument rests on anatomy, not on any ancient description. An adult elephant skull is mostly air-filled bone surrounding that central opening, and a dwarf elephant skull is still about twice the size of a human one. Found broken and weathered in a cave, it would look like the head of a huge, one-eyed person.

The idea lasted. In the 14th century, Giovanni Boccaccio described giant bones found in a cave near Trapani, in western Sicily, which local people took to be the remains of Polyphemus. Bones of extinct elephants are the most likely explanation.

Fossils, folklore and the limits of proof

The historian Adrienne Mayor has shown that Greeks and Romans collected, measured and displayed large fossil bones as relics of giants and heroes. The Roman biographer Suetonius records that the emperor Augustus decorated his villa on Capri with huge bones "called the bones of giants".

The Cyclops link is still a hypothesis. No ancient text describes a one-eyed skull, and the Polyphemus story may have older roots in folktale. Fossil skulls could have reinforced a myth rather than created it. Mainland Greece and islands such as Samos also have abundant fossils of large mammals, so the Sicilian dwarfs were not the only possible source. As someone with Sicilian roots, I find it irresistible that the island's giants may have been elephants all along, but the honest verdict is "plausible, not proven".

Why the elephants vanished

P. falconeri disappeared long before people arrived, probably as climate and sea levels changed and larger mainland animals reached the island. On other islands the story is less clear. At Akrotiri Aetokremnos on Cyprus, the bones of hundreds of pygmy hippos lie alongside stone tools about 12,000 years old. Some archaeologists see this as evidence that early settlers hunted the hippos to extinction. Others argue the bones accumulated naturally before people used the site.

Why it matters

The dwarf elephants of Sicily show island dwarfism at its most extreme, and they remind us that evolution can run in either direction on body size. They also show how old the conversation between fossils and storytelling is. People have always tried to explain strange bones in the ground. For other animals that shared the world with early humans, see Ice Age animals early humans encountered, or explore the human side of the story on the interactive family tree.