Dusicyon avus is an extinction species of canid native to South America during the Pleistocene and Holocene epochs. It was medium to large, about the size of a German shepherd.
Range
Dusicyon avus range extended through the
Pampas and
Patagonia in the south-central and southern parts of South America, with an estimated range of around 762 351 km². Its fossils have been found in the Luján Formation of
Argentina, the
Chui Formation of
Brazil, the Milodón Cave in
Chile and the
Sopas Formation of
Uruguay.
Diet and ecology
Its diet seems to have been more carnivorous than extant foxes based on δ
13C and δ
15N values, probably mostly preying on small mammals but also scavenging on large carcasses.
This is in contrast to the warrah, whose diet was restricted to the seabirds and seal pups available on the
Falkland Islands. Morphologically,
D. avus and
D. australis are most similar to
, suggesting a similar ecological niche.
Relationship to humans
A grave of the late second millennium BCE at Loma de los Muertos in General Conesa, Río Negro Argentina contains a sub-adult
D. avus, buried in a human mortuary context in a comparable manner to adjacent human burials. It may have been kept as a pet and been considered part of the human social group.
Another example is found in Cañada Seca, Mendoza Argentina.
Extinction
Dating of extinction
Dusicyon avus, according to earlier estimates, became extinct around 1000 BCE,
with possibilities that it became extinct as recently as 500 – 300 years
Before Present.
Recent research confirms more recent dates, with the last appearance datum in the Pampean Region being 700
Before Present (1232–1397 AD) and southernmost Patagonia at 400 years BP (1454–1626 AD).
Charles Darwin in The Voyage of the Beagle stated that "many sealers, , and Yaghan people, who have visited these islands the, all maintain that no such animal the is found in any part of South America" suggesting that it was unlikely to have been alive at this time. It is possible, but as yet unproven, that some populations of D. avus may have persisted until the time of European contact. Forty years before the introduction of the South American gray fox to Tierra del Fuego, there are some ethnographic references to the existence of two species of foxes there. Around 1900, the indigenous Selkʼnam people were recorded as recognizing two varieties of foxes, one of which grew to unusual size.
Reasons for extinction
The extinction of
D. avus as opposed to the
Island tameness D. australis is mysterious, as there is no clear reason why a generalised medium sized canid would go extinct, especially at such a late date after the Quaternary extinction event. There is no compelling evidence that climatic change was the cause of the extinction, nor any evidence that hybridisation with domestic dogs was the cause, as the skull morphology and DNA is consistent from the Late Pleistocene through the Holocene.
was used for ritual purposes by aboriginal peoples in the Late Holocene, and appears to have a high symbolic value
and its remains, usually teeth, are found in many archaeological sites.
, despite its wide range, has a low genetic diversity in tested samples, suggesting a possible low population or genetic bottleneck before extinction.
It is likely that a combination of both climatic and anthropogenic factors was the cause of their demise.
See also
