Ankylosaurinae

Ankylosaurinae is a subfamily of ankylosaurid dinosaurs, existing from the Early Cretaceous about 105 million years ago until the end of the Late Cretaceous, about 66 mya. Many genera are included in the clade, such as Ankylosaurus, Pinacosaurus, Euoplocephalus, and Saichania.

Ankylosaurinae
Temporal range: Cretaceous, 105–66 Ma
Scolosaurus thronus RTMP
Skeleton of Scolosaurus thronus, once referred to Euoplocephalus. Royal Tyrrell Museum of Palaeontology
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Order: Ornithischia
Family: Ankylosauridae
Subfamily: Ankylosaurinae
Brown, 1908[1]
Genera[1]

Features

Ankylosaurines are defined as being closer relatives to Ankylosaurus than to Shamosaurus.[2]

Diagnostic features of ankylosaurines include the nuchal shelf that obscures the occiput in dorsal view, and the quadrate condyle which is obscured lightly by the quadratojugal boss.[2]

Phylogeny

The following cladogram is based on the 50% majority rule phylogenetic analysis of Arbour & Currie (2015):[1]

Ankylosaurinae

Crichtonsaurus (nomen dubium)

Tsagantegia

Zhejiangosaurus (nomen dubium)

Pinacosaurus

Saichania

Tarchia

Zaraapelta

Ankylosaurini

Dyoplosaurus

Talarurus

Nodocephalosaurus

Ankylosaurus

Anodontosaurus

Euoplocephalus

Scolosaurus

Ziapelta

References

  1. ^ a b c Arbour, Victoria M.; Currie, Philip J. (2015). "Systematics, phylogeny and palaeobiogeography of the ankylosaurid dinosaurs". Journal of Systematic Palaeontology. 14 (5): 1. doi:10.1080/14772019.2015.1059985.
  2. ^ a b Weishampel, David B.; Dodson, Peter; Osmólska, Halszka (2004). The Dinosauria. Berkeley, CA and Los Angeles, CA and London, England: University of California Press. pp. 389, 861. ISBN 0-520-24209-2. Retrieved April 9, 2010.
Ahshislepelta

Ahshislepelta is a genus of herbivorous

ankylosaurine ankylosaurid dinosaur from Late Cretaceous (late Campanian stage) deposits of San Juan Basin, New Mexico, USA.

Ahshislepelta is known from the holotype SMP VP-1930, a closely associated and incomplete postcranial skeleton of an adult individual consisting of the shoulder girdle, a partial left forelimb, vertebrae and osteoderms. It was discovered in 2005 and collected between 2005 and 2009 from the Hunter Wash Member of the Kirtland Formation at the Ah-shi-sle-pah Wash locality. Ahshislepelta was first named by Michael E. Burns and Robert M. Sullivan in 2011 and the type species is Ahshislepelta minor. The generic name comes from the Ah-shi-sle-pah Wash locality, where the fossils were found, and pelta, "shield" in Greek. The specific name is derived from minor, "small" in Latin, in reference to its smaller adult size relative to other ankylosaurids from North America. Humerus length is thirty-one centimetres.Ahshislepelta was assigned to the Ankylosauridae and more precisely to the Ankylosaurinae.

Ankylosauridae

Ankylosauridae () are a family of the armored dinosaurs within Ankylosauria, and sister group to Nodosauridae. Ankylosaurids appeared 122 million years ago and went extinct 66 million years ago during the Cretaceous–Paleogene extinction event. These animals were mainly herbivorous and were obligate quadrupeds, with leaf-shaped teeth and robust, scute-covered bodies. Ankylosaurids possess a distinctly domed and short snout, wedge-shaped osteoderms on their skull, scutes along their torso, and a tail club.Ankylosauridae is exclusively known from the northern hemisphere, with specimens found in western North America, Europe, and East Asia. The first discoveries within this family were of the genus Ankylosaurus, by Peter Kaiser and Barnum Brown in Montana in 1906. Brown went on to name Ankylosauridae and the subfamily Ankylosaurinae in 1908.

Anodontosaurus

Anodontosaurus is an extinct genus of ankylosaurid dinosaurs within the subfamily Ankylosaurinae. It is known from the entire span of the Late Cretaceous Horseshoe Canyon Formation (mid Late Campanian to "middle" Maastrichtian stage, about 72.8-67 Ma ago) of southern Alberta, Canada. It contains two species, A. lambei and A. inceptus.

Crichtonpelta

Crichtonpelta is a genus of extinct herbivorous ankylosaurid dinosaur from the Cretaceous of China.In 2007, Lü Junchang, Ji Qiang, Gao Yubo and Li Zhixin named and described a second species of Crichtonsaurus: Crichtonsaurus benxiensis. The specific name refers to the Benxi Geological Museum.The holotype, BXGMV0012, is a skull found near Beipiao in a layer of the Sunjiawan Formation probably dating from the Albian. Specimen BXGMV0012-1, a skeleton lacking the skull, discovered in the same quarry as the holotype, was referred to the species. Furthermore, a skeleton with skull, displayed by the Sihetun Fossil Museum as a Crichtonsaurus bohlini specimen, was in 2014 referred to Crichtonpelta. In 2017, a fourth specimen was described, from the same quarry as the holotype, G20090034, consisting of a skull lacking the front snout.In 2014, Victoria Arbour concluded that Crichtonsaurus were a nomen dubium. Therefore, she named a separate genus for its second species: Crichtonpelta. The generic name combines a reference to Michael Crichton, the author of Jurassic Park, with a Greek πέλτη, peltè, "small shield". At the time this was an invalid nomen ex dissertatione. However, in 2015, Crichtonpelta was validly named by Arbour and Philip John Currie. The type species is Crichtonsaurus benxiensis; the combinatio nova is Crichtonpelta benxiensis. There was a possibility that, though Crichtonsaurus bohlini was a nomen dubium, its fossil material in fact belonged to Crichtonpelta. Arbour however, noted clear differences in the scapula and humerus between BXGMV0012-1 and LPM 101, a specimen previously referred to Crichtonsaurus bohlini: the scapula of the former has a tab-like acromion and its humerus a much longer deltopectoral crest.Arbour established several distinguishing traits. One of these was an autapomorphy, unique derived trait: the apex of the (quadrato)jugal, or cheek, horn, is pointing upwards. Also a unique combination of in themselves not unique traits is present. The upper snout armour forms an amorphous mass, not clearly separated into distinctive tiles. The jugal bone is deeper than that of Pinacosaurus. The skull roof is not notched at the lacrimal bone as in Pinacosaurus grangeri. The squamosal horns are shorter than those of Pinacosaurus mephistocephalus. However, these horns are longer and more pointed than those of Gobisaurus or Shamosaurus. The point of the cheek horn is located on the rear edge. The transverse crest on the top of the rear skull has two points.The holotype of Crichtonpelta is somewhat larger than Crichtonsaurus, itself about three to four metres long. It is uncertain whether Crichtonpelta already possessed a tail club.Crichtonpelta was, within the Ankylosauridae, placed in the Ankylosaurinae, in a basal position. If correct, this makes it the oldest known ankylosaurine.

Crichtonsaurus

Crichtonsaurus is a dubious genus of herbivorous ankylosaurid ankylosaur dinosaur. It was named for Michael Crichton, the author of the famed dinosaur novel Jurassic Park. It was an ankylosaurine, and it lived during the late Cretaceous Period of China.

Dyoplosaurus

Dyoplosaurus (meaning "double-armored lizard") is an extinct genus of ankylosaurid dinosaurs within the subfamily Ankylosaurinae. It is known from the lower levels of the Late Cretaceous Dinosaur Park Formation (latest middle Campanian stage, about 76.5 Ma ago) of Alberta, Canada. It contains a single species, Dyoplosaurus acutosquameus.

Euoplocephalus

Euoplocephalus ( yoo-OP-loh-SEF-ə-ləs) is a genus of very large, herbivorous ankylosaurian dinosaurs, living during the Late Cretaceous of Canada. It has only one named species, Euoplocephalus tutus.

The first fossil of Euoplocephalus was found in 1897 in Alberta. In 1902, it was named Stereocephalus, but that name had already been given to an insect, so it was changed in 1910. Later, many more ankylosaurid remains were found from the Campanian of North America and often made separate genera. In 1971, Walter Coombs concluded that they all belonged to Euoplocephalus which then would be one of the best-known dinosaurs. Recently however, experts have come to the opposite conclusion, limiting the authentic finds of Euoplocephalus to about a dozen specimens. These include a number of almost complete skeletons, so much is nevertheless known about the build of the animal.

Euoplocephalus was about five and a half meters long and weighed about two and a half tonnes. Its body was low-slung and very flat and wide, standing on four sturdy legs. Its head had a short drooping snout with a horny beak to bite off plants that were digested in the large gut. Like other ankylosaurids, Euoplocephalus was largely covered by bony armor plates, among them rows of large high-ridged oval scutes. The neck was protected by two bone rings. It could also actively defend itself against predators like Gorgosaurus using a heavy club-like tail end.

Gobisaurus

Gobisaurus is an extinct genus of herbivorous basal ankylosaurid ankylosaur from the Upper Cretaceous of China (Nei Mongol Zizhiqu). The genus is monotypic, containing only the species Gobisaurus domoculus.

Jinyunpelta

Jinyunpelta ("Jinyun shield") is a genus of herbivorous ankylosaurine thyreophoran dinosaur from the Cretaceous Liangtoutang Formation of Jinyun County, Zhejiang, China; it has one species, the type species J. sinensis. This species is the basalmost ankylosaur known to have had a proper tail club.

Nodocephalosaurus

Nodocephalosaurus is a genus of herbivorous ankylosaurine ankylosaurid dinosaur from Upper Cretaceous (late Campanian stage) deposits of San Juan Basin, New Mexico. The holotype was recovered from the Late Campanian De-na-zin Member of the Kirtland Formation and consists of an incomplete skull. Nodocephalosaurus (Greek nodus = knob, kephale = head and sauros = lizard) is a monotypic genus, including only the type species, Nodocephalosaurus kirtlandensis. Dinosaurs like Nodocephalosaurus resembled Asian forms, and may be evidence for Asian dinosaurs migrating to North America in the Late Cretaceous.

Oohkotokia

Oohkotokia ( OH-oh-kə-TOH-kee-ə) is a genus of ankylosaurid dinosaur within the subfamily Ankylosaurinae. It is known from the upper levels of the Two Medicine Formation (late Campanian stage, about 74 Ma ago) of Montana, United States. The discovery of Oohkotokia supports that Ankylosaurine dinosaurs existed and flourished continuously in Montana and/or Alberta throughout the late Campanian and early Maastrichtian stages in the Late Cretaceous period. It was a large, heavily built, quadrupedal, herbivore, that could grow up to 6 m (19.7 ft) long.

Pinacosaurus

Pinacosaurus ("plank lizard") is a genus of medium-sized ankylosaur dinosaurs that lived from the late Santonian to the late Campanian stages of the late Cretaceous Period (roughly 80–75 million years ago), in Mongolia and China.

The type species Pinacosaurus grangeri was named in 1933. Pinacosaurus mephistocephalus named in 1999, is a second possibly valid species, differing from the type species in details of the skull armour. Of Pinacosaurus grangeri many skeletons have been found, more than of any other ankylosaur. These predominantly consist of juveniles that perhaps lived in herds roaming the desert landscape of their habitat.

Pinacosaurus was about five metres long and weighed up to two tonnes. Its body was flat and low-slung but not as heavily built as in some other members of the Ankylosaurinae. The head was protected by bone tiles, hence its name. Each nostril was formed as a large depression pierced by between three and five smaller holes, the purpose of which is uncertain. A smooth beak bit off low-growing plants that were sliced by rows of small teeth and then swallowed to be processed by the enormous hind gut. Neck, back and tail were protected by an armour of keeled osteoderms. The animal could also actively defend itself by means of a tail club.

Platypelta

Platypelta is an extinct genus of herbivorous ankylosaurid dinosaurs within the subfamily Ankylosaurinae. It is known from the Late Cretaceous Dinosaur Park Formation (early Late Campanian stage, about 77.5-76.5 Ma ago) of southern Alberta, Canada. The type species is Platypelta coombsi.

Saichania

Saichania (Mongolian meaning "beautiful one") is a genus of herbivorous ankylosaurid dinosaur from the Late Cretaceous period of Mongolia and China.

The first fossils of Saichania were found in the early 1970s in Mongolia. In 1977 the type species Saichania chulsanensis was named. The description of this species has been based on limited fossil material; especially the rear of the animal is not well known.

Saichania was over five metres long and weighed over two tonnes. It was more robustly built than other members of the Ankylosauridae. Neck vertebrae, shoulder girdle, ribs and breast bones were fused or firmly connected. Its body was flat and low-slung, standing on four short legs. The forelimbs were very powerful. The head was protected by bulbous armour tiles. It could defend itself against predators like Tarbosaurus with a tail-club. On the torso keeled osteoderms were present. Saichania bit off plants in its desert habitat with a horny beak and processed them in its wide hindgut.

Scolosaurus

Scolosaurus is an extinct genus of ankylosaurid dinosaurs within the subfamily Ankylosaurinae. It is known from either the lower levels of the Dinosaur Park Formation or upper levels of the Oldman Formation (the location of the type specimen's quarry is uncertain) in the Late Cretaceous (latest middle Campanian stage, about 76.5 Ma ago) of Alberta, Canada. It contains two species, S. cutleri and S. thronus.

Shanxia

Shanxia is a genus of ankylosaurid dinosaur that lived during the upper Cretaceous Period. Its fossils were recovered and named after the Shanxi Province of China, and it is known only from scrappy remains found in river deposits. Based on the relative lengths of the femur and other leg bones, it probably reached a length of around 3.6 metres (12 ft).

Barrett et al. (1998) distinguished Shanxia from other ankylosaurs in having long and flattened triangle-shaped horns that project backward from the squamosal bones on either side of the rear portion of its skull at an angle of 145 degrees. However, Sullivan (1999) considered Shanxia a nomen dubium, possibly synonymous with the related ankylosaurid Tianzhenosaurus, arguing that the unique shape of the squamosal horns could be a product of individual variation, but Upchurch and Barrett (2000) reaffirmed the validity of Shanxia. In their systematic review of ankylosaurids, Arbour and Currie (2015) treated Shanxia as a junior synonym of Saichania.

Talarurus

Talarurus ( TAL-ə-ROOR-əs; meaning "Wicker tail") is an extinct genus of ankylosaurid dinosaur that lived approximately 90 million years ago during the latter part of the Cretaceous Period in what is now Mongolia. Talarurus was a hippopotamus-sized, heavily built, ground-dwelling, quadrupedal herbivore, that could grow up to an estimated 6 m (19.7 ft) long. Like other ankylosaurs it had heavy armour and a club on its tail. Along with Tsagantegia, Talarurus is one of the oldest known ankylosaurines from Asia and one of the better-known ankylosaurs from Mongolia.

Tarchia

Tarchia (meaning "brainy one") is a genus of herbivorous ankylosaurid dinosaur from the late Cretaceous of Mongolia.

Tsagantegia

Tsagantegia (; meaning "of Tsagan-Teg"; Tumanova, 1993) is a genus of medium-sized ankylosaurid dinosaur from the Upper Cretaceous Mongolia, during the Cenomanian stage.

The holotype specimen (GI SPS N 700/17), a complete skull, was recovered from the Bayan Shireh Formation (Cenomanian-Santonian), at the Tsagan-Teg ("White Mountain") locality, Dzun-Bayan, in the southeastern Gobi Desert, Mongolia. The genus is monotypic, including only the type species, T. longicranialis.

This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.