Unquillosaurus

Unquillosaurus
Temporal occurrence
	Upper Cretaceous ( Maastrichtian )
	72 to 66 million years
Locations
	Salta , Argentina ( Los Blanquitos Formation );
Systematics
	Lizard dinosaur (Saurischia)
	Theropoda
	Maniraptora
	Deinonychosauria
	Dromaeosauridae
	Unquillosaurus
Scientific name
	Unquillosaurus
	Powell , 1979
Art
	Unquillosaurus ceibalii;

Unquillosaurus was a theropod dinosaur believed to be a member of the Dromaeosauridae group. Only one bone of this genus is known to date - a pubis , which was discovered in the Argentine province of Salta and is between 72 and 66 million years old ( Maastrichtian , Upper Cretaceous ).

features

The pubic bone found is 51 cm long, the entire animal could have reached about 3 meters in length. This find shows a number of derived (modern) features: For example, the pubic bone was turned backwards ( ophistopubic ). The lower end of the pubic boot was shortened craniocaudally , its length is less than 30% of the total length of the pubic bone. In addition, the pubic boot proximodistal was relatively high. These inferred traits are also found in early birds, indicating that Unquillosaurus was closely related to the birds. Unquillosaurus can be distinguished from other theropods by a deep channel at the front end of the pubic bone.

Systematics

Originally, due to the size of the bone , Jaime Eduardo Powell (1979) assumed that Unquillosaurus was a representative of the carnosaurs , a group to which most of the known large theropods were counted at the time. Fernando Novas and Federico Agnolin (2004) re-studied the fossil and came to the conclusion that Unquillosaurus belongs to the Coelurosauria group Metornithes, along with the Alvarezsaurids , the Therizinosauroids , the Oviraptorosaurs , the Deinonychosauriern and the birds . Within the Metornithes, Unquillosaurus could possibly belong to the Dromaeosauridae, according to the researchers. Today the Metornithes taxon is considered invalid and is no longer used. Other studies - Norell and Makovicky (2004) and Martínez and Novas (2006) - also see Unquillosaurus as a possible dromaeosaurid.

Find, research history and naming

The only find so far comes from the Arroyo Morterito locality, a site near El Ceibal in the southern end of the Sierra de la Candelaria in the southeast of the Argentine province of Salta . In addition to Unquillosaurus, two other dinosaur species could be identified from this site - the sauropod Laplatasaurus sp. and another, but indeterminable, sauropod. The excavations at the Arroyo Morterito site were completed in 1975. Stratigraphically , the site belongs to the upper section of the Los Blanquitos Formation , a layer member of the Salta Group , which consists of red to orange continental sandstones and conglomerates .

The find is a left pubic bone ( holotype , specimen number PVL 3670-11). It was first scientifically described in 1979 by Jaime Eduardo Powell, along with the remains of the sauropods . The name Unquillosaurus refers to the Río Unquillo , a river in whose catchment area the site is located. The specific epithet ceibalii points to El Caibal , the place to which the site is closest. In 2004 Fernando Novas and Federico Agnolin published a re-examination of Unquillosaurus .

Individual evidence

↑ Thomas R. Holtz Jr .: Supplementary Information. to: Thomas R. Holtz Jr .: Dinosaurs. The most complete, up-to-date Encyclopedia for Dinosaur Lovers of all ages. Random House, New York NY 2007, ISBN 978-0-375-82419-7 , online (PDF; 184.08 KB) .

↑ ^a ^b ^c Fernando E. Novas , Federico L. Agnolin: Unquillosaurus cebali Powell, a giant maniraptoran (Dinosauria, Theropoda) from the Late Cretaceous of Argentina. In: Revista del Museo Argentino de Ciencias Naturales. NS Vol. 6, No. 1, 2004, ISSN 1514-5158 , pp. 61-66, digital version (PDF; 319.82 KB) .

↑ ^a ^b ^c ^d James E. Powell: On a dinosaur association and other evidences of Upper Cretaceous vertebrates from La Candelaria region, Province of Salta, Argentina. In: Ameghiniana. Vol. 16, No. 1/2, 1979, ISSN 0002-7014 , pp. 191-204.

^ Metornithes. In: The Paleobiology Database. Retrieved July 31, 2014 .

↑ Mark Norell , Peter Makovicky : Dromaeosauridae. In: David B. Weishampel , Peter Dodson , Halszka Osmólska (eds.): The Dinosauria . 2nd edition. University of California Press, Berkeley CA et al. 2004, ISBN 0-520-24209-2 , pp. 196-209.

^ Ruben D. Martínez, Fernando E. Novas: Aniksosaurus darwini gen. Et sp. nov., a new coelurosaurian theropod from the early Late Cretaceous of central Patagonia, Argentina. In: Revista del Museo Argentino de Ciencias Naturales. NS Vol. 8, No. 2, 2006, pp. 243-259, digitized version (PDF; 1.34 MB) ( Memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked . Please check the original and archive link according to the instructions and then remove this notice. . @1@ 2

[1] Thomas R. Holtz Jr .: Supplementary Information. to: Thomas R. Holtz Jr .: Dinosaurs. The most complete, up-to-date Encyclopedia for Dinosaur Lovers of all ages. Random House, New York NY 2007, ISBN 978-0-375-82419-7 , online (PDF; 184.08 KB) .

[novas_04-2] Fernando E. Novas , Federico L. Agnolin: Unquillosaurus cebali Powell, a giant maniraptoran (Dinosauria, Theropoda) from the Late Cretaceous of Argentina. In: Revista del Museo Argentino de Ciencias Naturales. NS Vol. 6, No. 1, 2004, ISSN 1514-5158 , pp. 61-66, digital version (PDF; 319.82 KB) .

[powell_79-3] James E. Powell: On a dinosaur association and other evidences of Upper Cretaceous vertebrates from La Candelaria region, Province of Salta, Argentina. In: Ameghiniana. Vol. 16, No. 1/2, 1979, ISSN 0002-7014 , pp. 191-204.

[4] Metornithes. In: The Paleobiology Database. Retrieved July 31, 2014 .

[dinosauria-5] Mark Norell , Peter Makovicky : Dromaeosauridae. In: David B. Weishampel , Peter Dodson , Halszka Osmólska (eds.): The Dinosauria . 2nd edition. University of California Press, Berkeley CA et al. 2004, ISBN 0-520-24209-2 , pp. 196-209.