''Canis etruscus'', the Etruscan wolf, is an extinct species of canine that was

endemic Endemism is the state of a species being found 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 found else ...

to Mediterranean Europe during the Early Pleistocene. The Etruscan wolf has been described as a small wolf-like dog. The Etruscan wolf has been accepted as the ancestor of '' C. mosbachensis'', that is the ancestor of the

grey wolf The wolf (''Canis lupus''; : wolves), also known as the gray wolf or grey wolf, is a large canine native to Eurasia and North America. More than thirty subspecies of ''Canis lupus'' have been recognized, and gray wolves, as popularly ...

(''C. lupus''), for a long time. Recent research has suggested that ''C. borjgali'' from

Dmanisi Dmanisi ( ka, დმანისი, tr, , az, Başkeçid) is a town and archaeological site in the Kvemo Kartli region of Georgia approximately 93 km southwest of the nation’s capital Tbilisi in the river valley of Mashavera. The hominin ...

has to be considered the ancestor of '' C. mosbachensis''.

Taxonomy

The

fossil record A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

for ancient

vertebrates Vertebrates () comprise all animal taxa within the subphylum Vertebrata () (chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with c ...

is composed of rarely occurring fragments, from which it is often impossible to obtain genetic material. Researchers are limited to morphologic analysis but it is difficult to estimate the intra-species and inter-species variations and relationships that existed between specimens across time and place. Some observations are debated by researchers who do not always agree, and hypotheses that are supported by some authors are challenged by others. Several species of

Caninae The Caninae, known as canines, are one of three subfamilies found within the canid family. The other two canid subfamilies are the extinct Borophaginae and Hesperocyoninae. The Caninae includes all living canids and their most recent fossil rel ...

from the Pleistocene of Europe have been described. Most of their systematic and

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

relationships have not been resolved because of their similar morphology. Upper Valdarno is the name given to that part of the

Arno The Arno is a river in the Tuscany region of Italy. It is the most important river of central Italy after the Tiber. Source and route The river originates on Monte Falterona in the Casentino area of the Apennines, and initially takes a ...

valley situated in the provinces of

Florence Florence ( ; it, Firenze ) is a city in Central Italy and the capital city of the Tuscany Regions of Italy, region. It is the most populated city in Tuscany, with 383,083 inhabitants in 2016, and over 1,520,000 in its metropolitan area.Bilan ...

and Arezzo, Italy. The region is bounded by the Pratomagno mountain range to the north and east and by the

Chianti A Chianti wine (, also , ) is any wine produced in the Chianti region of central Tuscany. It was historically associated with a squat bottle enclosed in a straw basket, called a ''fiasco'' ("flask"; ''pl. fiaschi''). However, the ''fiasco'' is ...

mountains to the south and west. The Upper Valdarno Basin has provided the remains of three fossil canid species dated to the Late Villafranchian era of Europe, 1.9–1.8 million years ago, that arrived with a faunal turnover around that time. The Swiss paleontologist Charles Immanuel Forsyth Major discovered two species in this region, these being the Falconer's wolf (''

Canis falconeri ''Xenocyon'' ("strange dog") is an extinct subgenus of ''Canis''. The group includes ''Canis'' (''Xenocyon'') ''africanus'', ''Canis'' (''Xenocyon'') ''antonii'' and ''Canis'' (''Xenocyon'') ''falconeri'' that gave rise to ''Canis'' (''Xenocyon'' ...

'' Forsyth Major 1877) that was later reclassified as ''Lycaon falconeri'', and the smaller Etruscan wolf (''C. etruscus'' Forsyth Major 1877). Forsyth Major did not publish a complete description of the Etruscan wolf, and later Domenico Del Campana worked on expanding Forsyth Major's descriptions when he recognized among the specimens a smaller,

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

-sized species. This he named the Arno River dog (''C. arnensis'' Del Campana 1913) in honour of the nearby

river.

Type Specimen

The

lectotype In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the ...

is a cranium from an unrecorded locality of Upper Valdarno. It is housed in the

Montevarchi Montevarchi is a town and ''comune'' in the province of Arezzo, Tuscany, Italy. History The town of Montevarchi sprang up around 1100, near to a fortified Benedictine monastery, founded by bishop Elempert (986–1010) of Arezzo. At first the cas ...

Paleontological Museum. The specimen has been designed as lectotype by the Italian paleontologist Danilo Torre in 1967 from the sample described by Forsyth Major.

''Canis apolloniensis''

One specimen of ''C. apolloniensis'' (Koufos and Kostopoulos, 1997) was found in site of Apollonia-1 near the village of Nea Apollonia, Macedonia, in northern

Greece Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders ...

. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of sever ...

consists of the rostral portion of a skull and a

mandible In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...

. In 2011, a study compared all of the fifty-five Early Pleistocene wolf-like specimens found across Europe and suggested that their morphometric variation was no different to that of modern wolf populations, with their difference in size representing male and female specimens. However, the study proposed two lineages. One lineage is '' C. arnensis'' which includes ''C. accitanus'' and ''C. senezensis'', and the other lineage being ''C. etruscus'' that includes ''C. apolloniensis''. Other studies contrast with this biometric interpretation. Considering morphological features retained by ''C. apolloniensis'', this species should be considered as a synonym of '' C. mosbachensis'' or a very affine taxon.

Lineage

The large wolf-sized ''Canis'' first appeared in the Middle

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Shanxi Province, China. 2.5 million years ago its range included the Nihewan Basin in Yangyuan County,

Hebei Hebei or , (; alternately Hopeh) is a northern province of China. Hebei is China's sixth most populous province, with over 75 million people. Shijiazhuang is the capital city. The province is 96% Han Chinese, 3% Manchu, 0.8% Hui, and 0 ...

, China, and Kuruksay, Tajikistan. In Europe, ''C. etruscus'' first appeared 1.9-1.8 million years ago. The lineage from ''C. etruscus'' to the Mosbach wolf (''C. mosbachensis'' Soergel, 1925) to the grey wolf (''C. lupus'') is widely accepted in the European scientific literature. Nevertheless, a recent publication has challenged this well-established hypothesis showing that the peculiarity of the ''C. etruscus'' (as shown by Cherin et al., 2014) do not fit with those of more modern Early Pleistocene canids like ''C. borjgali'' from

, probably the ancestor wolf-like crown-clade species ('' C. lupus'', '' C. latrans'', '' C. lupaster''). The French archaeologist Jean-Philip Brugal proposes ''C. mosbachensis'' as a subspecies of ''C. etruscus'', and another French archaeologist,

Henry de Lumley Henry de Lumley (born 1934 in Marseille) is a French archeologist, geologist and prehistorian. He is director of the Institute of Human Paleontology in Paris, and Professor Emeritus at the Museum of Natural History in Paris. He is also a corres ...

, considers ''C. mosbachensis'' to be a subspecies of the grey wolf and proposes a classification of ''C. lupus mosbachensis''.

Paleoecology

The dispersal of carnivoran species occurred approximately 1.8 million years ago and this coincided with a decrease in precipitation and an increase in annual seasonality which followed the 41,000-year amplitude shift of

Milankovitch cycles Milankovitch cycles describe the collective effects of changes in the Earth's movements on its climate over thousands of years. The term was coined and named after Serbian geophysicist and astronomer Milutin Milanković. In the 1920s, he hypot ...

. First to arrive was ''C. etruscus'', which was immediately followed by ''C. arnensis'' and ''Lycaon falconeri'', and then the giant hyena ''

Pachycrocuta ''Pachycrocuta'' is an extinct genus of prehistoric hyenas. The largest and most well-researched species is ''Pachycrocuta brevirostris'', colloquially known as the giant short-faced hyena as it stood about at the shoulder and it is estimated t ...

brevirostris''. These were all better adapted to open, dry landscapes than the two more primitive canini '' Eucyon'' and '' Nyctereutes'' that they replaced in Europe.

Description

A description of the Etruscan wolf appears below:

Medium-sized dog (average size of a small ''C. lupus''); elongated snout; marked constriction of the snout beyond the
infraorbital foramina In human anatomy, the infraorbital foramen is one of two small holes in the skull's upper jawbone ( maxillary bone), located below the eye socket and to the left and right of the nose. Both holes are used for blood vessels and nerves. In anatomic ...
; elongated nasal bones extending beyond the maxillofrontal suture; well-developed
sagittal The sagittal plane (; also known as the longitudinal plane) is an anatomical plane that divides the body into right and left sections. It is perpendicular to the transverse and coronal planes. The plane may be in the center of the body and divi ...
and nuchal crests; laterally enlarged occipital region; P1-P2-P3 laterally compressed; P1 with lingual cingulum; P3 normally with both posterior and accessory cusp (=modified posterior cingulum); large relative length of the upper molar row (in comparison with ''C. arnensis''); M1 with paracone more elevated than metacone; labial basin of M1 as deep as but larger than the lingual one; M1 and M2 with a continuous cingulum; reduced contact area between M1 and M2. Lower dentition characterized by larger dimensions in respect to ''C. arnensis'' and by a wolf-like M1/M2 ratio. The lower
carnassial Carnassials are paired upper and lower teeth modified in such a way as to allow enlarged and often self-sharpening edges to pass by each other in a shearing manner. This adaptation is found in carnivorans, where the carnassials are the modified f ...
(M1) is distinguished by main
trigonid The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone ...
cusps (
protoconid Many different terms have been proposed for features of the tooth crown in mammals. The structures within the molars receive different names according to their position and morphology. This nomenclature was developed by Henry Fairfield Osborn i ...
and paraconid) relatively small (in comparison with ''C. lupus'') and by talonid cusps ( hypoconid and entoconid) linked by a sinuous cristid.

Describing ''C. etruscus'' as wolf-like and ''C. arnensis'' as jackal-like is therefore an over-simplification, because ''C. arnensis'' is more similar to ''C. lupus'' than is ''C. etruscus'' in some cranial characters. ''C. etruscus'' shows a set of peculiar features.

Range

In the Early Pleistocene, from Spain to China.

Extinction

The Etruscan wolf and the Arno River dog both disappeared from the fossil record in Italy after the end of the Tasso Faunal Unit and were replaced by the mid-Pleistocene era Mosbach wolf (''C. mosbachensis'' Soergel, 1925) by 1.5 million years ago.

References

{{Taxonbar, from=Q30682478 Pleistocene carnivorans Pleistocene mammals of Europe Prehistoric canines Wolves Fossil taxa described in 1877