Deltatheroida

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Deltatheroida
Temporal range: Aptian–Paleocene
Sulestes reconstruction.jpg
Sulestes reconstruction
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Clade: Metatheria
Order: Deltatheroida
Gregory and Simpson, 1926
Families and genera

Deltatheroida is an extinct group of basal metatherians that were distantly related to modern marsupials. [2] The majority of known members of the group lived in the Cretaceous; one species, Gurbanodelta kara, is known from the late Paleocene (Gashatan) of China. [3] Their fossils are restricted to Central Asia and North America. This order can be defined as all metatherians closer to Deltatheridium than to Marsupialia.

Contents

When they were first identified in the 1920s, they were believed to be placentals and possible ancestors of the "creodonts" (a polyphyletic group of extinct carnivorous mammals from the Paleogene and Miocene), but this was later disproven. Nonetheless, deltatheroideans do converge on hyaenodontids, oxyaenids, carnivorans, dasyuromorphs, thylacoleonids and sparassodonts in many details of their dental anatomy, suggesting a carnivorous lifestyle. [4]

Taxonomy

The following is a species list of Deltatheroida. [5] [6]

†Deltatheroida Kielan-Jaworowska 1982 [Deltatheralia Marshall & Kielan-Jaworowska 1992; Holarctidelphia Szalay 1993]

Biology

Deltatheroideans are thought to be carnivorous mammals, converging on hyaenodontids, oxyaenids, carnivorans, dasyuromorphs and sparassodonts in many details of their dental anatomy, suggesting a carnivorous lifestyle. [4] [8]

Deltatheroideans in this regard appear to have replaced eutriconodont mammals as the dominant carnivorous mammals of the Mesozoic, either directly through competition or occupying vacant ecological niches; in North America, Nanocuris came to succeed the larger gobiconodontids and Jugulator , while in Asia the Early Cretaceous gobiconodontid radiation is replaced in the Late Cretaceous by a deltatheroidean one. [9] Given that all insectivorous and carnivorous mammals groups suffered heavy losses during the mid-Cretaceous, it seems likely these metatherians simply occupied niches left after the extinction of most eutriconodonts. [10]

Evidence of direct predation on dinosaurs may be attested on a skull belonging to Archaeornithoides , which seems to have been punctured by Deltatheridium teeth and later healed. [11]

See also

Related Research Articles

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Didelphodon is a genus of stagodont metatherians from the Late Cretaceous of North America.

<i>Repenomamus</i> Extinct genus of mammals

Repenomamus is a genus of opossum- to badger-sized gobiconodontid mammal containing two species, Repenomamus robustus and Repenomamus giganticus. Both species are known from fossils found in China that date to the early Cretaceous period, about 125-123.2 million years ago. R. robustus is one of several Mesozoic mammals for which there is good evidence that it fed on vertebrates, including dinosaurs. Though it is not entirely clear whether or not these animals primarily hunted live dinosaurs or scavenged dead ones, evidence for the former is present in fossilized remains showcasing the results of what was most likely a predation attempt by R. robustus directed at a specimen of the dinosaur Psittacosaurus lujiatunensis. R. giganticus is among the largest mammals known from the Mesozoic era, only surpassed by Patagomaia.

<i>Pucadelphys</i> Extinct genus of mammals

Pucadelphys is an extinct genus of non-marsupial metatherian. The genus contains a single species, P. andinus. Fossils of Pucadelphys have been found in the Santa Lucía Formation in Tiupampa in Bolivia.

<i>Alphadon</i> Extinct genus of mammals

Alphadon is an extinct genus of small, primitive mammal that was a member of the metatherians, a group of mammals that includes modern-day marsupials. Its fossils were first discovered and named by George Gaylord Simpson in 1929.

<span class="mw-page-title-main">Eutriconodonta</span> Extinct order of mammals

Eutriconodonta is an order of early mammals. Eutriconodonts existed in Asia, Africa, Europe, North and South America during the Jurassic and the Cretaceous periods. The order was named by Kermack et al. in 1973 as a replacement name for the paraphyletic Triconodonta.

<span class="mw-page-title-main">Gobiconodontidae</span> Extinct family of mammals

Gobiconodontidae is a family of extinct mammals that ranged from the mid-Jurassic to the early Late Cretaceous, though most common during the Early Cretaceous. The Gobiconodontids form a diverse lineage of carnivorous non-therian mammals, and include some of the best preserved Mesozoic mammal specimens.

<span class="mw-page-title-main">Deltatheridiidae</span> Extinct family of mammals

Deltatheridiidae is an extinct family of basal carnivorous metatherians that lived during the Cretaceous and Paleogene. They were closely related to marsupials. Their fossils are restricted to Central Asia and North America. They mostly disappeared in the KT event, but a ghost lineage, currently represented by Gurbanodelta, survived until the late Paleocene by decreasing in size and becoming insectivorous.

Nanocuris is an extinct genus of Deltatheridiidae from the Cretaceous of Canada (Saskatchewan) and United States. Initially, it was classified in a proper family, Nanocuridae, in the clade Eutheria, but a reanalysis of a new specimen revealed a delthatheroid affinity of the genus.

<span class="mw-page-title-main">Stagodontidae</span> Extinct family of mammals

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<i>Pappotherium</i> Extinct family of mammals

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<i>Siamoperadectes</i> Genus of non-marsupial metatherian from the Miocene of Thailand

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<i>Ichthyoconodon</i> Extinct family of mammals

Ichthyoconodon is an extinct genus of eutriconodont mammal from the Lower Cretaceous of Morocco. It is notable for having been found in a unique marine location, and the shape of its teeth suggests an unusual, potentially fish-eating ecological niche. Analysis suggests it is part of a group of gliding mammals that includes Volaticotherium.

Oxlestes is an extinct mammal from the Late Cretaceous of Asia, more specifically from the Cenomanian of Uzbekistan. A carnivorous species of uncertain affinities, it is notable for its relatively large size, being among the largest of all Mesozoic mammals. Due to the limited amount of material, it has been considered a nomen dubium.

Alticonodon is a genus of extinct mammal from the Late Cretaceous of North America. It is one of the geologically youngest known eutriconodonts, and is a fairly more specialised animal than earlier representatives of this clade.

The "Gurlin Tsav" skull is a currently unnamed carnivorous metatherian fossil from the Nemegt Formation of Mongolia. Composed of a single semi-complete skull, this specimen is notable in regards to the evolution and systematics of Metatheria as a whole, and thus nigh-omnipresent in phylogenetic analyses of this group.

Khuduklestes is a genus of extinct mammal of uncertain affinities from the Late Cretaceous of China. It is rather similar to the also carnivorous and taxonomically uncertain Oxlestes, being slightly smaller.

<i>Tsagandelta</i> Extinct family of mammals

Tsagandelta is a genus of deltatheroidean therian mammal that lived in Asia during the Late Cretaceous. Distantly related to modern marsupials, it is part of Deltatheroida, a lineage of carnivorous metatherians common in the Cretaceous of Asia and among the most successful non-theropod carnivores of the region. It represents the first known mammal from the Bayan Shireh Formation.

<span class="mw-page-title-main">Plagiaulacoid</span> Mammalian tooth

A plagiaulacoid is a type of blade-like, most often serrated, tooth present in various mammal groups, usually a premolar. Among modern species it is present chiefly on diprotodontian marsupials, which have both the upper and lower first premolars converted into serrated blades. However, various other extinct groups also possessed plagiaulacoids. These would be multituberculates, some "Plesiadapiformes" such as Carpolestes and various metatherians such as Epidolops and various early diprotodontians. In many of these only a lower premolar became converted into a blade, while the upper premolars showed less specialisation.

<i>Asiatherium</i> Extinct genus of mammals

Asiatherium is an extinct genus of mammal, probably belonging to Metatheria. It lived during the Late Cretaceous, and its fossilized remains were discovered in Mongolia.

Albertatherium is an extinct genus of alphadontid metatherians that lived during the Late Cretaceous of North America. The genus contains two species, Albertatherium primus, and Albertatherium secundus. Fossils have been found in the Eagle Formation of Montana and the Milk River Formation of Alberta.

References

  1. 1 2 Guillermo W. Rougier; Brian M. Davis; Michael J. Novacek (2015). "A deltatheroidan mammal from the Upper Cretaceous Baynshiree Formation, eastern Mongolia". Cretaceous Research. 52, Part A: 167–177. doi:10.1016/j.cretres.2014.09.009.
  2. Wilson, G.P.; Ekdale, E.G.; Hoganson, J.W.; Calede, J.J.; Linden, A.V. (2016). "A large carnivorous mammal from the Late Cretaceous and the North American origin of marsupials". Nature Communications. 7: 13734. Bibcode:2016NatCo...713734W. doi:10.1038/ncomms13734. PMC   5155139 . PMID   27929063.
  3. Xijun Ni; Qiang Li; Thomas A. Stidham; Lüzhou Li; Xiaoyu Lu; Jin Meng (2016). "A late Paleocene probable metatherian (?deltatheroidan) survivor of the Cretaceous mass extinction". Scientific Reports. 6: Article number 38547. Bibcode:2016NatSR...638547N. doi:10.1038/srep38547. PMC   5141426 . PMID   27924847.
  4. 1 2 CHRISTIAN DE MUIZON and BRIGITTE LANGE-BADRÉ, Carnivorous dental adaptations in tribosphenic mammals and phylogenetic reconstruction, Article first published online: 29 MAR 2007 DOI: 10.1111/j.1502-3931.1997.tb00481
  5. Mikko's Phylogeny Archive Haaramo, Mikko (2007). "†Deltatheroida – deltatherids" . Retrieved 30 December 2015.
  6. Paleofile.com (net, info) "Paleofile.com". Archived from the original on 2016-01-11. Retrieved 2015-12-30.. "Taxonomic lists- Mammals". Archived from the original on 11 January 2016. Retrieved 30 December 2015.
  7. S. Bi, X. Jin, S. Li and T. Du. 2015. A new Cretaceous metatherian mammal from Henan, China. PeerJ 3:e896
  8. Zofia Kielan-Jaworowska; Richard L. Cifelli; Zhe-Xi Luo (2004). "Chapter 12: Metatherians". Mammals from the Age of Dinosaurs: origins, evolution, and structure. New York: Columbia University Press. pp. 425–262. ISBN   0-231-11918-6.
  9. G. W. Rougier, B. M. Davis, and M. J. Novacek. 2015. A deltatheroidan mammal from the Upper Cretaceous Baynshiree Formation, eastern Mongolia. Cretaceous Research 52:167-177
  10. David M. Grossnickle, P. David Polly, Mammal disparity decreases during the Cretaceous angiosperm radiation, Published 2 October 2013.DOI: 10.1098/rspb.2013.2110
  11. Elżanowski, A. Wellnhoffer, P. (1993). "Skull of Archaeornithoides From the Upper Cretaceous of Mongolia". earth.geology.yale.edu/~ajs/1993/11.1993.08Elzanowski.pdf . American Journal of Science

Further reading

Zofia Kielan-Jaworowska, Richard L. Cifelli, and Zhe-Xi Luo, Mammals from the Age of Dinosaurs: Origins, Evolution, and Structure (New York: Columbia University Press, 2004), 444-448.