''Kerberos'' (" Cerberus") is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of hyainailourid

hyaenodonts Hyaenodontidae ("hyena teeth") is a family of extinct predatory mammals from extinct superfamily Hyaenodontoidea within extinct order Hyaenodonta. Hyaenodontids arose during the early Eocene and persisted well into the early Miocene. Fossils of t ...

in polyphyletic tribe

Hyainailourini Hyainailourini ("hyena-cats") is an extinct polyphyletic tribe of hyainailourid hyaenodonts from paraphyletic subfamily Hyainailourinae that lived in Africa, Asia and Europe during the middle Eocene to middle Miocene. Classification and phyloge ...

within

paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

Hyainailourinae Hyainailourinae ("hyena-cats") is an extinct paraphyletic subfamily of hyainailourid hyaenodonts that lived in Africa, Asia, North America and Europe during the middle Eocene to middle Miocene. Classification and phylogeny Taxonomy * Subfamily: ...

, that lived in

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

. It contains the single species ''Kerberos langebadreae''.

Etymology

The genus name ''Kerberos'' comes from Cerberus, the hound of

Hades Hades (; grc-gre, ᾍδης, Háidēs; ), in the ancient Greek religion and myth, is the god of the dead and the king of the underworld, with which his name became synonymous. Hades was the eldest son of Cronus and Rhea, although this also ...

, a multi-headed dog that guards the entrance to the

Underworld The underworld, also known as the netherworld or hell, is the supernatural world of the dead in various religious traditions and myths, located below the world of the living. Chthonic is the technical adjective for things of the underworld. ...

Greek mythology A major branch of classical mythology, Greek mythology is the body of myths originally told by the Ancient Greece, ancient Greeks, and a genre of Ancient Greek folklore. These stories concern the Cosmogony, origin and Cosmology#Metaphysical co ...

. The species name, ''Kerberos langebadreae'', is dedicated to the French

palaeontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...

Dr. Brigitte Lange-Badré, who contributed extensively to the knowledge of Eocene carnivorous mammals.

Description

''Kerberos langebadreae'' is the only currently known

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

from genus ''Kerberos'', and it was an extinct large-bodied

carnivorous A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other sof ...

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

from the

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

. It represents one of the oldest members of the subfamily Hyainailourinae that have been recorded in

. Many hyaenodont species are known only from fragments of the jaw or a few teeth. ''K. langebadreae'' represents the first instance where

cranial Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

, dental and postcranial material of an early hyainailourine have been found associated with each other. The material that has been referred to ''K. langebadreae'' includes a nearly complete cranium, left and right halves of the lower jaw, a

fibula The fibula or calf bone is a leg bone on the lateral side of the tibia, to which it is connected above and below. It is the smaller of the two bones and, in proportion to its length, the most slender of all the long bones. Its upper extremity is ...

and several

foot The foot ( : feet) is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is a separate organ at the terminal part of the leg made ...

bones including the astragalus,

calcaneus In humans and many other primates, the calcaneus (; from the Latin ''calcaneus'' or ''calcaneum'', meaning heel) or heel bone is a bone of the tarsus of the foot which constitutes the heel. In some other animals, it is the point of the hock. S ...

, metatarsals 1-3 and two middle

phalanxes The phalanx ( grc, φάλαγξ; plural phalanxes or phalanges, , ) was a rectangular mass military formation, usually composed entirely of heavy infantry armed with spears, pikes, sarissas, or similar pole weapons. The term is particularly use ...

. ''K. langebadreae'' displays both primitive and derived features. Among the former is the anteriorly narrow jaw and the small space between the first and second lower premolars. The derived features include a

premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has b ...

that is narrow along is full length as well as several dental characteristics. The skull of ''K. langebadreae'' is about 35 cm long, similar in size to that of a female

brown bear The brown bear (''Ursus arctos'') is a large bear species found across Eurasia and North America. In North America, the populations of brown bears are called grizzly bears, while the subspecies that inhabits the Kodiak Islands of Alaska is kno ...

. The snout is very short. The shape of the skull indicates large jaw muscles, suggesting that ''K. langebadreae'' had a powerful bite. The molars of ''K. langebadreae'' were cutting whereas the premolars display a shape and wear pattern more consistent with crushing action.

Body mass

''Kerberos langebadreae'' was a large hyaenodont and is thought to have weighed around 140 kg based on

measurements Measurement is the quantification of attributes of an object or event, which can be used to compare with other objects or events. In other words, measurement is a process of determining how large or small a physical quantity is as compared t ...

of the teeth, skull and astragalus. This makes ''K. langebadreae'' one of the largest carnivores known from the Eocene of Europe.

Ecology

Montespieu, the locality where ''Kerberos langebadreae'' was found, is part of the “Castrais” fauna which is thought to be of Bartonian age. Both ''Kerberos'' and '' Paroxyaena'' were much larger than the proviverrid hyaenodonts that lived in Europe at the same time and are therefore unlikely to have been in direct

competition Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indivi ...

with them. The small proviverrids may have even been their prey. Based on the neck

vertebrae The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic i ...

of closely related hyaenodonts, it is thought that ''Kerberos langebadreae'' and its relatives had powerful necks which allowed them to restrain struggling prey. This, together with the powerful jaw muscles and crushing premolars, suggests that ''K. langebadreae'' was capable of both hunting and scavenging similarly to the modern

spotted hyena The spotted hyena (''Crocuta crocuta''), also known as the laughing hyena, is a hyena species, currently classed as the sole extant member of the genus ''Crocuta'', native to sub-Saharan Africa. It is listed as being of least concern by the IUC ...

. Unlike the modern hyena, however, the foot bones of ''K. langebadreae'' indicate that it had a

plantigrade 151px, Portion of a human skeleton, showing plantigrade habit In terrestrial animals, plantigrade locomotion means walking with the toes and metatarsals flat on the ground. It is one of three forms of locomotion adopted by terrestrial mammals. T ...

posture and was not an efficient runner. ''K. langebadreae'' likely preyed on animals which were larger than itself, such as ungulates like '' Choeropotamus'', ''

Lophiodon ''Lophiodon'' (from el, λόφος , 'crest' and el, ὀδούς 'tooth') is an extinct genus of mammal related to chalicotheres. It lived in Eocene Europe Europe is a large peninsula conventionally considered a continent in its own r ...

'' and ''

Palaeotherium ''Palaeotherium'' (Ancient Greek for 'old beast') is an extinct genus of perissodactyl ungulate known from the Mid Eocene to earliest Oligocene of Europe. First described by French naturalist Georges Cuvier in 1804, ''Palaeotherium'' was among t ...

''. Because of its large size it would have been an important apex predator.

Classification and phylogeny

Relations

The species ''Kerberos langebadreae'' was created along with the genus in 2015 by Solé and colleagues based on a

fossil 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 ...

skull, lower jaw and a number of associated hindlimb elements. The fossils were discovered in 1981 by Dominique Vidalenc at Montespieu, near the city of

Lautrec Lautrec (; oc, Lautrèc) is a commune in the Tarn department in southern France. Demography Remarkable sites Lautrec is listed among "The Most Beautiful Villages of France" as well as a "Remarkable Site for Taste" thanks to its renowned ...

in the department of Tarn in southern France. They were shown to come from a hyaenodont and were referred to a new genus and species. The original study placed ''K. langebadreae'' within the subfamily Hyainailourinae. More recent studies, using Bayesian tip dating, placed ''Kerberos langebadreae'' as the

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and t ...

to '' Pterodon dasyuroides''. The phylogenetic relationships of gebus ''Kerberos'' are shown in the following cladogram:

References

{{Taxonbar, from1=Q50387375, from2=Q50402181 Hyaenodonts Prehistoric mammals of Europe Prehistoric mammal genera