Eobaatar

Eobaatar is a genus of extinct mammal from the Lower Cretaceous of Mongolia, Spain and England. A member of the also extinct order Multituberculata, it lies within the suborder Plagiaulacida and family Eobaataridae. The genus Eobaatar was named by Kielan-Jaworowska Z., Dashzeveg D. and Trofimov B.A. in 1987.

Eobaatar
Temporal range: Early Cretaceous
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Multituberculata
Family: Eobaataridae
Genus: Eobaatar
Species
  • E. hispanicus
  • E. magnus
  • E. minor
  • E. pajaronensis (?)

Species

Eobaatar hispanicus

This species was named by Hahn G. and Hahn R. in 1992. Remains consisting of a single tooth were found in Hauterivian - Barremian (Lower Cretaceous)-age strata of Galve, Spain.

Eobaatar magnus

This species was named by Kielan-Jaworowska Z., Dashzeveg D. and Trofimov B.A. in 1987. It is based on a fragment of lower jaw with teeth found in Aptian or Albian (Lower Cretaceous) strata of the Höövör beds in Guchin Us County, Mongolia, and had a cranial length of about 3 cm.

Eobaatar minor

This species was also named by Kielan-Jaworowska Z., Dashzeveg D. and Trofimov B.A. in 1987. Remains were found in Lower Cretaceous strata of Mongolia. Going by the species name, it was probably relatively small; his skull was 2 cm in length indeed.

Eobaatar pajaronensis

This species was named by Hahn G. and Hahn R. in 2001. Remains were discovered in Barremian (Lower Cretaceous) strata of Ple pajaron in Spain.

Eobaatar clemensi

This species was named by Steven Sweetman in 2009. Remains were found in the Barremian (lower Cretaceous) of the Wessex formation, England.

Sources

  • Zofia Kielan-Jaworowska, Richard L. Cifelli, and Zhe-Xi Luo (2004). "Mammals from the age of dinosaurs : origins, evolution, and structure" pp. 260–342. ISBN 0-231-11918-6
  • Hahn & Hahn (2001), "Multituberculaten-zähne aus der Unter-Kreide (Barremium) von Ple Pajaron (Prov. Cuenca, Spanien)". Paläontologische Zeitschrift 74 (4), p. 587-589.
  • Kielan-Jaworowska et al. (1987), "Early Cretaceous multituberculates from Mongolia and a comparison with Late Jurassic form". Acta Palaeontologica Polonica 32, p. 3-47.
  • Kielan-Jaworowska Z & Hurum JH (2001), "Phylogeny and Systematics of multituberculate mammals". Paleontology 44, p. 389-429.
  • Much of this information has been derived from MESOZOIC MAMMALS: Plagiaulacidae, Albionbaataridae, Eobaataridae & Arginbaataridae
  • S. C. Sweetman. 2009. A new species of the plagiaulacoid multituberculate mammal Eobaatar from the Early Cretaceous of southern Britain. Acta Palaeontologica Polonica 54(3):373-384
Albian

The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous epoch/series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± 0.9 Ma (million years ago). The Albian is preceded by the Aptian and followed by the Cenomanian.

Aptian

The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous epoch or series and encompasses the time from 125.0 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ago), approximately. The Aptian succeeds the Barremian and precedes the Albian, all part of the Lower/Early Cretaceous.The Aptian partly overlaps the upper part of the regionally used (in Western Europe) stage Urgonian.

The Selli Event, also known as OAE1a, was one of two oceanic Anoxic events in the Cretaceous period, which occurred around 120 Ma and lasted approximately 1 to 1.3 million years. The Aptian extinction was a minor extinction event hypothesized to have occurred around 116 to 117 Ma.

Barremian

The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 129.4 ± 1.5 Ma (million years ago) and 125.0 ± 1.0 Ma). It is a subdivision of the Early Cretaceous epoch (or Lower Cretaceous series). It is preceded by the Hauterivian and followed by the Aptian stage.

Eobaataridae

Eobaataridae is a family of fossil mammal within the order Multituberculata. Remains are known from the Lower Cretaceous of Europe and Asia. These herbivores thus lived during the Mesozoic era, also known as the "age of the dinosaurs". They were among the most derived representatives of the informal suborder "Plagiaulacida".

In this case of one taxon, remains are reasonably well known. This refers to Sinobaatar from the extraordinary Chinese locality of Liaoning. They were close relatives of the Plagiaulacidae, while the second upper molar has similarities to ones known from the informal Paracimexomys group within the more derived suborder, Cimolodonta.

The recently described Indobaatar from the Early Jurassic Kota Formation is the earliest known multituberculate, let alone the earliest eobaatarid, and may stretch the eobaatarid-cimolodontan group much earlier than previously thought.Genus Teutonodon is the first Jurassic mammal discovered in Germany.

Eotyrannus

Eotyrannus (meaning "dawn tyrant") is a genus of tyrannosauroid theropod dinosaur hailing from the Early Cretaceous Wessex Formation beds, included in Wealden Group, located in the southwest coast of the Isle of Wight, United Kingdom. The remains (MIWG1997.550), consisting of assorted skull, axial skeleton and appendicular skeleton elements, from a juvenile or subadult, found in a plant debris clay bed, were described by Hutt et al. in early 2001. The etymology of the generic name refers to the animals classification as an early tyrannosaur or "tyrant lizard", while the specific name honors the discoverer of the fossil.

Hauterivian

The Hauterivian is, in the geologic timescale, an age in the Early Cretaceous epoch or a stage in the Lower Cretaceous series. It spans the time between 132.9 ± 2 Ma and 129.4 ± 1.5 Ma (million years ago). The Hauterivian is preceded by the Valanginian and succeeded by the Barremian.

La Huérguina Formation

The La Huérguina Formation (also known as the Calizas de La Huérguina Formation, La Huérguina Limestone Formation or as the Una Formation) is a geological formation in Spain whose strata date back to the Barremian stage of the Early Cretaceous.Las Hoyas is a Konservat-Lagerstätte within the formation, located near the city of Cuenca, Spain. The site is mostly known for its exquisitely preserved dinosaurs, especially enantiornithines.

List of multituberculate species

This is a taxonomic list of species in the extinct mammalian order Multituberculata.

Multituberculata

Multituberculata (commonly known as multituberculates, named for the multiple tubercles of their teeth) is an extinct taxon of rodent-like allotherian mammals that existed for approximately 166 million years, the longest fossil history of any mammal lineage. They eventually declined from the late Palaeocene onwards, disappearing in the late Eocene, though they might have lived even longer into the Miocene, if gondwanatheres are part of this group. More than 200 species are known, ranging from mouse-sized to beaver-sized. These species occupied a diversity of ecological niches, ranging from burrow-dwelling to squirrel-like arborealism to jerboa-like hoppers. Multituberculates are usually placed as crown mammals outside either of the two main groups of living mammals—Theria, including placentals and marsupials, and Monotremata—but closer to Theria than to monotremes.

Plagiaulacida

Plagiaulacida is a group of extinct multituberculate mammals. Multituberculates were among the most common mammals of the Mesozoic, "the age of the dinosaurs". Plagiaulacids, an informal suborder, are the most basal of this order, and ranged from the Middle Jurassic Period to the Lower Cretaceous Period of the northern hemisphere.

Kielan-Jaworowska and Hurum (2001) divides “Plagiaulacida” into three informal lineages, the paulchoffatiids, the plagiaulicids, and the allodontids.

Wessex Formation

The Wessex Formation is a fossil-rich English geological formation that dates from the Berriasian to Barremian stages (about 145–125 million years ago) of the Early Cretaceous. It forms part of the Wealden Group and underlies the younger Vectis Formation and overlies the Durlston Formation. The dominant lithology of this unit is mudstone with some interbedded sandstones.

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