The Sardinian dhole (genus ''Cynotherium'' especially ''C. sardous'') is an extinct insular

canid Canidae (; from Latin, ''canis'', "dog") is a family (biology), biological family of caniform carnivorans, constituting a clade. A member of this family is also called a canid (). The family includes three subfamily, subfamilies: the Caninae, a ...

which was

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to what is now the

Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...

islands of

Sardinia Sardinia ( ; ; ) is the Mediterranean islands#By area, second-largest island in the Mediterranean Sea, after Sicily, and one of the Regions of Italy, twenty regions of Italy. It is located west of the Italian Peninsula, north of Tunisia an ...

and

Corsica Corsica ( , , ; ; ) is an island in the Mediterranean Sea and one of the Regions of France, 18 regions of France. It is the List of islands in the Mediterranean#By area, fourth-largest island in the Mediterranean and lies southeast of the Metro ...

during the Middle-Late Pleistocene. It went extinct at the end of the Pleistocene around the time of human settlement of the islands. Its scientific name means "dog-beast of Sardinia", the

genus name Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial spec ...

from the and and the specific name from the , alt. form of . Around the size of a jackal, morphological studies indicate it was a specialised stalking predator of small mammals and birds, with a probable preference for the endemic

Sardinian pika The Sardinian pika (''Prolagus sardus'') is an extinct species of lagomorph that was endemic to the islands of Sardinia, Corsica and neighbouring Mediterranean islands until its extinction likely in Roman times. It was the last surviving member o ...

Evolution

The oldest remains of ''Cynotherium'' on Sardinia date to around the early-Middle Pleistocene transition around 800,000 years ago, associated with a faunal turnover event on Sardinia likely caused low sea levels allowing dispersal to Sardinia-Corsica from mainland Italy. ''Cynotherium'' is suggested to have originated from the species '' Xenocyon lycaonoides'' of mainland Europe. Some of the older ''Cynotherium'' remains are assigned to the separate species ''Cynotherium malatestai,'' which is larger than ''C. sardous'' and shows intermediate features between it and ''X. lycaonoides.'' A 2021 genetic study found that its closest living relative is the

dhole The dhole ( ; ''Cuon alpinus'') is a canid native to South, East and Southeast Asia. It is anatomically distinguished from members of the genus ''Canis'' in several aspects: its skull is convex rather than concave in profile, it lacks a third ...

, from which it diverged approximately 885,000 years ago. The study found that the lineage of the Sardinan dhole and dhole emerged from the hybridisation between a lineage closely related to the genus ''

Canis ''Canis'' is a genus of the Caninae which includes multiple extant taxon, extant species, such as Wolf, wolves, dogs, coyotes, and golden jackals. Species of this genus are distinguished by their moderate to large size, their massive, well-develo ...

'' and a lineage related to the

African wild dog The African wild dog (''Lycaon pictus''), also called painted dog and Cape hunting dog, is a wild canine native to sub-Saharan Africa. It is the largest wild canine in Africa, and the only extant member of the genus '' Lycaon'', which is disti ...

(''Lycaon pictus'') in proportions of roughly 65% and 35% respectively. The modern dhole was also found to have additional African wild dog related ancestry (making up around 25% of its genome) not found in the Sardinan dhole.

Description

''C. sardous'' was relatively small in size, with a weight around , comparable to a

jackal Jackals are Canidae, canids native to Africa and Eurasia. While the word has historically been used for many canines of the subtribe Canina (subtribe), canina, in modern use it most commonly refers to three species: the closely related black-b ...

. The skull is slender and wedge-shaped in lateral view. The snout is narrower than in extant dholes, but broader than those of foxes. The postorbital region of the skull is broad, and the zygomatic arches only modestly project outwards. The

mastoid The mastoid part of the temporal bone is the posterior (back) part of the temporal bone, one of the bones of the skull. Its rough surface gives attachment to various muscles (via tendons) and it has openings for blood vessels. From its borders, t ...

is very enlarged and projects outwards. The

sagittal crest A sagittal crest is a ridge of bone running lengthwise along the midline of the top of the skull (at the sagittal suture) of many mammalian and reptilian skulls, among others. The presence of this ridge of bone indicates that there are excepti ...

is weakly developed. The mandible is slender. The attachment sites for the

triceps The triceps, or triceps brachii (Latin for "three-headed muscle of the arm"), is a large muscle on the ventral, back of the upper limb of many vertebrates. It consists of three parts: the medial, lateral, and long head. All three heads cross the ...

on the scapula, ulna and humerus are large, indicating the muscle, along with the anconeus, was well developed. The scar for the

deltoid muscle The deltoid muscle is the muscle forming the rounded contour of the shoulder, human shoulder. It is also known as the 'common shoulder muscle', particularly in other animals such as the domestic cat. Anatomically, the deltoid muscle is made up o ...

at the posterior of the deltoid ridge on the humerus is high, large and rugose, indicating this muscle was also well developed. Analysis of its ear morpology, including the significant reduction in the number of

cochlea The cochlea is the part of the inner ear involved in hearing. It is a spiral-shaped cavity in the bony labyrinth, in humans making 2.75 turns around its axis, the modiolus (cochlea), modiolus. A core component of the cochlea is the organ of Cort ...

r turns, suggests a specialisation towards the hearing of high-frequency sounds, but suggests it was poor at detecting low frequency sounds, and completely unable to detect sounds lower than 250 Hz.

Ecology

When the ancestor of this canid became confined to the island, its diet became limited to small prey. ''Cynotherium'' as a predator specializing in small, fast moving prey is supported by an examination of the animal's anatomy. The evolution of short, powerful limbs, a low neck carriage and increased head and neck mobility suggests an animal specialised for stalking low to the ground, and then quickly pouncing on or running down prey.PDF copy
/ref> A suggested preferred prey item of the Sardinian dhole is the

(''Prolagus sardus''), a large

lagomorph The lagomorphs () are the members of the taxonomic order Lagomorpha, of which there are two living families: the Leporidae (rabbits and hares) and the Ochotonidae ( pikas). There are 110 recent species of lagomorph, of which 109 species in t ...

that was also endemic and abundant on the island, with birds also being likely targets.

Paleoenvironment

During the Middle and Late Pleistocene Corsica and Sardinia had their own highly

depauperate terrestrial mammal fauna which besides the Sardinian dhole and Sardinian pika, included the Tyrrhenian field rat, ('' Rhagamys orthodon'') the Tyrrhenian vole ('' Microtus henseli''), a shrew ('' Asoriculus similis''), a mole ('' Talpa tyrrhenica''), a dwarf mammoth ( ''Mammuthus'' ''lamarmorai''), a galictine

mustelid The Mustelidae (; from Latin , weasel) are a diverse family of carnivoran mammals, including weasels, badgers, otters, polecats, martens, grisons, and wolverines. Otherwise known as mustelids (), they form the largest family in the suborde ...

('' Enhydrictis galictoides''), three species of otter ('' Algarolutra majori, Sardolutra ichnusae, Megalenhydris barbaricina'') and a deer ('' Praemegaceros cazioti'').

Extinction

The youngest radiocarbon dates for the Sardinan dhole are around 11,500 years BC/13,500 years

Before Present Before Present (BP) or "years before present (YBP)" is a time scale used mainly in archaeology, geology, and other scientific disciplines to specify when events occurred relative to the origin of practical radiocarbon dating in the 1950s. Because ...

(BP), only a few thousand years before the first confirmed human presence on Sardian-Corsica around 8,000 BC/10,000 years BP, and it is assumed that the species was alive when humans arrived on the island. The causes of its extinction are uncertain. The low genetic diversity of sampled individuals suggests that the population size had been small but stable for a long period of time prior to extinction.

References

External links

ISPRA
Photo of ''Cynotherium sardous'' {{Taxonbar, from1=Q2118534, from2=Q18578603 Canina (subtribe) Prehistoric mammals of Europe Fauna of Corsica Fauna of Sardinia Extinct mammals of Europe Pleistocene carnivorans Pleistocene extinctions Extinct canines Fossil taxa described in 1857 Mammals described in 1857