Dingoes recognized as a full species

Photo credit. André Geißenhöner

Scottish zoologist Robert Kerr published the first volume of what would be the two volume The Animal Kingdom in 1792. On page 144 he used the combination Canis antarctitus for the Australian wild dog. The following year, Friedrich Meyer a German physician and naturalist again described the Australia wild dog on pages 33-35 of his 1793 book Systematisch-summarische Uebersicht der neuesten zoologischen Entdeckungen in Neuholland und Afrika, (a volume that mostly focused on African primates and birds). The name dingo was long applied to the Australian dogs but Kerr’s name Canis antarcticus was overlooked. But, C. antarcticus should have had priority given it was published before Meyer’s description. ICZN Opinion 0.451 suppressed Kerr’s name and Meyer’s Canis dingo became the approved scientific name for Australia’s wild dogs to maintain nomenclature stability.

The dingo, is Australia's largest land predator as well as a controversial taxon threatened by hybridization with domestic dogs. Dingoes are thought to have arrived in Australia more than 5000 YBP (Years Before Present), and because of their isolation they became a unique canid. How to distinguish ‘pure’ dingoes from dingo-dog hybrids is an issue that has been recently dealt with in a paper by Crowther et al (2014).

 Crowther et al. notes that the confusion exists because there is no description or series of original specimens against which the identities of putative hybrid and ‘pure’ dingoes can be assessed. Current methods to classify dingoes have poor discriminatory abilities because natural variation within dingoes is poorly understood. Also, it is unknown if hybridization may have altered the genome of post-19th century reference specimens. The new research provides a description of the dingo based on pre-20th century specimens that are unlikely to have been influenced by hybridization.

The authors reasoned that because Australia was colonized by Europeans in 1788 and was only sparsely inhabited by European settlers prior to 1900, dingoes collected before this date would be less likely to have been influenced by hybridization with domestic dogs. A search for museum specimens collected prior 1900 produced a sample of 69 dingo skulls and six skins as well as specimens collected from archaeological and paleontological deposits dated before 1900. They used radiocarbon (C14) dating to determine if specimens from cave deposits lacking data on their context pre-dated 1900. Selected for comparison were domestic dogs of similar size which were or have frequently been used as stock-working dogs and hunting dogs in Australia. Thus it is likely they have interbred with dingoes. These breeds included Australian cattle dogs, kelpies, collies and greyhounds.

They found dingoes differ from the domestic dog in having a relatively larger palatal width, a relatively longer rostrum, a relatively shorter skull height and a relatively wider top ridge of skull. The pre-20th century dingoes were also found to lacked dewclaws on the hind legs. In the sample of 19th century dingo skins they found considerable variability in the color and including various combinations of yellow, white, ginger and darker variations from tan to black.

Diagnosing the dingo remains difficult due to the overlap in morphological characters with domestic dogs, localized adaptations in dingoes and morphological variation through time. Identification of diagnostic morphological characters is also difficult, especially when there is more variation within the domestic dogs in shape and size than in the entire canid clade. The morphological analyses showed that there is considerable overlap between domestic dogs and dingoes for most morphological characters. This was particularly the case for some Australian breeds, such as the Australian cattle dog, which are thought to have dingo ancestry. A similar degree of overlap in shape exists between North American wolves and closely related husky dogs.

Recognizing the dingo as a full species is likely to remain controversial. But, lineage based species concepts will likely accept the dingo as a species. The full article is available on-line.

Citations

Crowther MS, Fillios M, Colman N and Letnic M. 2014. An updated description of the Australian dingo (Canis dingo Meyer, 1793). Journal of Zoology, 293: 192–203. doi: 10.1111/jzo.12134.