''Jugulator'' is an extinct genus of

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

s from the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

. It contains one species, ''Jugulator amplissimus''. A

eutriconodont Eutriconodonta is an order (biology), order of early mammals. Eutriconodonts existed in Asia (including Insular India, pre-contact India), Africa, Europe, North America, North and South America during the Jurassic and the Cretaceous periods. The ...

, it is known from the Cedar Mountain Formation, and is both a large sized and possibly ecologically specialised taxon, showcasing the diversity of mammals in the

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

Description

''Jugulator'' is known primarily from isolated teeth and dentaries. The species is most distinctive in regards to its large size, being among the largest mammals in the region, some lower molars exceeding 5 mm in length and with an estimated body weight of about 750 g. The medial lower incisor is greatly enlarged, with a mitten-shaped crown that bears sharp cutting surfaces.

Phylogeny

Always recognised as a triconodontid

, the most recent phylogenetic studies recover ''Jugulator'' as the sister taxon of a clade comprising ''

Volaticotherium ''Volaticotherium antiquum'' (meaning "ancient gliding beast") is an extinct, gliding, insectivorous mammal that lived in Asia during the Jurassic period, around 164 mya. It is the only member of the genus ''Volaticotherium''. The discovery of ...

'', '' Ichthyoconodon'', '' Triconolestes'', and ''

Argentoconodon ''Argentoconodon'' (meaning "Argentina cone tooth") is an extinct genus of theriimorph mammal from the Cañadón Asfalto Formation of the Cañadón Asfalto Basin in Patagonia. When originally described, it was known only from a single molarifo ...

'', known as Volaticotherini.A. O. Averianov and A. V. Lopatin. 2011. Phylogeny of Triconodonts and Symmetrodonts and the Origin of Extant Mammals. Doklady Biological Sciences 436:32-35 . Uhen/M. Uhen/ref>

Cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

after Gaetano & Rougier, 2011:

Biology

''Jugulator'' is noted as being a rather large mammal for Mesozoic standards. Combined with the general adaptations for carnivory that eutriconodonts display, it is safe to say that it was a predator of other vertebrates like mammals, lizards and small dinosaurs. Other large eutriconodonts like ''

Repenomamus ''Repenomamus'' (Latin: "reptile" (reptilis), "mammal" (mammalis)) is a genus of opossum- to badger-sized Gobiconodontidae, gobiconodontid mammal containing two species, ''Repenomamus robustus'' and ''Repenomamus giganticus''. Both species are kn ...

'' and '' Gobiconodon'' show evidence of scavenging and direct predation on such creatures, so it is likely that ''Jugulator'' also displayed these behaviours.

Ecology

''Jugulator'' occurs in the mid-Cretaceous deposits of the Cedar Mountain Formation, where several of North America's more iconic dinosaurs like '' Utahraptor'' and '' Cedarosaurus'' occur. A large variety of mammal species are known from here as well, including other eutriconodonts like '' Astroconodon'' and '' Corviconodon'' as well as

multituberculate Multituberculata (commonly known as multituberculates, named for the multiple tubercles of their teeth) is an extinct order of rodent-like mammals with a fossil record spanning over 130 million years. They first appeared in the Middle Jurassic, a ...

s like ''

Cedaromys ''Cedaromys'' ("Cedar mouse") is an extinct mammal which lived during the Upper Cretaceous, at the same time as many dinosaurs. It was a member of the also extinct order of Multituberculata. It's within the suborder of Cimolodonta, and a possible ...

'' and '' Janumys'' and several

theria Theria ( or ; ) is a scientific classification, subclass of mammals amongst the Theriiformes. Theria includes the eutherians (including the Placentalia, placental mammals) and the metatherians (including the marsupials) but excludes the egg-lay ...

n mammals such as '' Montanalestes'' and '' Atokatheridium''. These diverse mammal faunas offer a transition from dominant taxa in the

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...

and the multituberculate and therian dominated laurasian mammalian faunas of the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

References

{{Taxonbar, from=Q22285226 Triconodontidae Early Cretaceous mammals Fossil taxa described in 1998 Cretaceous mammals of North America