Island Weirdness #56 — Cynotherium sardous

Despite being decent swimmers, canids are surprisingly rare in island ecosystems, only seeming to end up there when able to move over land connections with larger landmasses (or when brought there by humans). Even the most remote species, the recently-extinct Falkland Island wolf, is thought to have crossed over a short stretch of sea ice during the last glacial period.

So the existence of a unique canid on the Mediterranean islands of Sardinia and Corsica is quite unusual.

The Sardinian dhole (Cynotherium sardous) was a small fox-sized canid, just 50cm tall at the shoulder (1’8″), related to the modern African wild dog and dhole. It was probably descended from the much larger wolf-like Xenocyon, which would have been able to reach Sardinia-Corsica during the early-to-mid Pleistocene about 1.2 million years ago, at a time when lower sea levels connected the island to the European mainland via Tuscany.

Isolated with very little large prey, it instead evolved to specialize in hunting small fast-moving animals, flattening its body low to the ground while stalking in a similar manner to modern foxes or Ethiopian wolves. Powerful shoulder muscles allowed it to launch into sudden high-speed lunges, and it had an especially strong flexible neck that would have been used to grab at its zig-zagging targets and shake them to death.

Cynotherium went extinct sometime in the early Holocene, around 11,000 years ago, after the arrival of humans on Sardinia and Corsica.

The earliest definite human remains on Sardinia are at least 20,000 years old, and while it’s unclear if those were permanent settlers it still seems like Cynotherium was able to deal with the effects of a human presence for several thousand years, probably due to its main prey (the Sardinian pika) also surviving at the time. So its disappearance may have been caused by a combination of problems that slowly whittled away at its population, like the warming climate, gradual habitat destruction, and competition from introduced predators like feral dogs — or possibly even new diseases caught from them.

Island Weirdness #55 — Megalenhydris barbaricina

Along with its miniature mammoths, the Mediterranean island of Sardinia (and neighboring Corsica) had an unusually large amount of endemic mustelids during the Pleistocene and early Holocene. There were at least four different otters — probably all descended from a single species of Lutra — that occupied various ecological niches in both the rivers and the coasts, and also an enigmatic grison-like terrestrial species.

Megalenhydris barbaricina was the largest of the Sardinian-Corsican otters, reaching lengths of over 2m (6’6″), slightly bigger than the modern South American giant river otter. Its crushing teeth indicate it specialized in crunching through hard-shelled invertebrates like molluscs and crustaceans, and its highly flexible backbone and flattened tail suggest it was a strong swimmer that may have been even more aquatic than most other otters.

It was possibly an equivalent of the modern sea otter, spending most of its time in the water, although it’s not clear whether it was a river or marine species.

Dating on the one known partial skeleton of Megalenhydris is uncertain, but it may be late Pleistocene to early Holocene in age, between about about 70,000 and 10,000 years old. Unfortunately this puts it within the same age range as the arrival of humans on Sardinia and Corsica, and its extinction may have been a direct result of being hunted for its meat and pelt.

Island Weirdness #53 — Tiny Elephants On Parade Part 5: Western Mediterranean

During the Pleistocene elephants colonized many of the islands in the Mediterranean Sea, with each island independently developing its own unique dwarfed form.

A stylized illustration of an extinct pygmy mammoth. It has long tightly-curved tusks, small ears, and a coat of hair over its body.
Mammuthus lamarmorai

Mammuthus lamarmorai lived on the island of Sardinia during the middle and late Pleistocene, between about 450,000 and 40,000 years ago. Standing around 1.4m tall at the shoulder (4’7″), it was a dwarf form roughly one-third the size of its ancestor, the huge Eurasian steppe mammoth.

Its remains are known only from the west and south of the island. Strangely it appears to be have been absent from the nearby island of Corsica, despite the two being joined as a single landmass a few times during lower sea level periods in the Pleistocene.

It’s not clear why this mini-mammoth disappeared. The date of the earliest human settlement of Sardinia is controversial (ranging from 250,000 to 20,000 years ago), so Mammuthus lamarmorai might never have actually encountered them. Instead it may have struggled to cope with climate changes during the last glacial period towards the end of the Pleistocene, which rapidly turned Sardinia colder and drier.


A stylized illustration of an extinct dwarf elephant. It has long thin tusks and tiny ears, and its body shape resembles a chubby baby elephant.
Palaeoloxodon falconeri

Over on Sicily and Malta (which were also occasionally a single island when sea levels were lower), there were several different species of miniature elephant during the mid-to-late Pleistocene, each with a different body size and occupying its own ecological niche. They were all descendants of the massive straight-tusked elephant (Palaeoloxodon antiquus) but each resulted from independent colonization waves swimming over to the island(s).

Palaeoloxodon falconeri lived during the mid-Pleistocene, about 550,000 years ago, and was both the smallest of the Mediterranean dwarfs and possibly the smallest elephant to ever exist. Just 0.8-1m tall (2’7″-3’3″), it had adult body proportions resembling the juveniles of its ancestors, limbs adapted for running and clambering over rough terrain, and a proportionally enormous brain relative to its body size.

Around 200,000 years ago a sea level drop allowed new colonization from the Italian mainland. If Palaeoloxodon falconeri was still around at that time it likely didn’t survive long with new competition from large herbivores like bison and deer, and being preyed on by newly-arriving large carnivores like wolves, lions, and hyenas.

Another small elephant soon evolved to take its place, although due to the presence of predators it was never able to get nearly so tiny.

A stylized illustration of an extinct dwarf elephant. It has short thick twisting mammoth-like tusks and small ears.
Palaeoloxodon mnaidriensis

Palaeoloxodon mnaidriensis was in fact one of the largest dwarf elephants in the Mediterranean, standing about 1.8-2m tall (5’11”-6’6″), but despite its larger size its limbs still show signs of adaptation for more fast and agile movement. Its tusks also show a lot of variation in shape, with some much more curved and twisted than others.

This elephant had disappeared by about 13,000 years ago, probably due to the climate significantly warming towards the end of the last ice age. Much like Sardinia, the earliest arrival of humans on Sicily and Malta is controversial, and it’s unclear whether they ever encountered Palaeoloxodon mnaidriensis — the earliest definite date for Sicily is about 16,000 years ago, so a human-induced extinction can’t be ruled out entirely.

The subfossil remains of the Siculo-Maltese elephants may have also ended up inspiring legends of the cyclops, as their skulls would have resembled large human ones with the nasal cavity forming a single big “eye socket”.