Jugulator (mammal)

Jugulator
Temporal range: 105–94 Ma
Life restoration as a gliding mammal.
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Eutriconodonta
Family: Volaticotheria
Genus: Jugulator
Cifelli & Madsen, 1998
Type species
Jugulator amplissimus
Cifelli & Madsen, 1998

Jugulator is a genus of extinct mammal from the Cretaceous of North America. A eutriconodont, 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.[1]

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.[1][2]

Phylogeny

Always recognised as an triconodontid eutriconodont,[1] the most recent phylogenetic studies recover Jugulator as part of a clade also including Volaticotherium, Ichthyoconodon, Triconolestes and Argentoconodon, tentatively known as Volaticotheria.[3][4][5]

Biology

Jugulator is noted as being a rather large mammal for Mesozoic standards.[1] 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 and Gobiconodon show evidence of scavenging and direct predation on such creatures, so it is likely that Jugulator also displayed these behaviours.[2]

Jugulator's closest relatives are known to be gliders,[3] so it can be assumed via phylogenetic bracketing that it was probably also one.

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 multituberculates like Cedaromys and Janumys and several therian mammals such as Montanalestes and Atokatheridium. These diverse mammal faunas offer a transition from dominant taxa in the Early Cretaceous and the multituberculate and therian dominated laurasian mammalian faunas of the Late Cretaceous.

References

  1. 1 2 3 4 Cifelli, Richard L.; Madsen, Scott K. (1998). "Triconodont mammals from the medial Cretaceous of Utah". Journal of Vertebrate Paleontology. 18 (2): 403–411. doi:10.1080/02724634.1998.10011068.
  2. 1 2 Kielan-Jaworowska, Zofia; Cifelli,, Richard L.; Luo, Zhe-Xi (2004). "Chapter 7: Eutriconodontans". Mammals from the Age of Dinosaurs: Origins, Evolution, and Structure. New York: Columbia University Press. pp. 216–248. ISBN 0-231-11918-6.
  3. 1 2 Gaetano, Leandro C.; Rougier, Guillermo W. (2011). "New materials of Argentoconodon fariasorum (Mammaliaformes, Triconodontidae) from the Jurassic of Argentina and its bearing on triconodont phylogeny". Journal of Vertebrate Paleontology. 31 (4): 829–843. doi:10.1080/02724634.2011.589877.
  4. Thomas Martin, Jesús Marugán-Lobón, Romain Vullo, Hugo Martín-Abad, Zhe-Xi Luo & Angela D. Buscalioni (2015). A Cretaceous eutriconodont and integument evolution in early mammals. Nature 526, 380–384. doi:10.1038/nature14905
  5. 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 [M. Uhen/M. Uhen]
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