Skeleton of Citipati sp. (IGM 100/42) in the Experimentarium in Copenhagen
|Upper Crayon (middle Campanium )|
|80.6 to 76.4 million years|
|Clark , Norell & Barsbold , 2001|
Citipati is a genus theropod dinosaur from the group of oviraptorosauria , from the Upper Cretaceous of Mongolia . It was a large oviraptorid with a distinctive skull crest.
This genus was the kind ( type species ) Citipati osmolskae in 2001 first described . There may be another species that has not yet been named and is known as Citipati sp. to be led.
Like related genera, Citipati showed a short and deep skull with toothless jaws formed into a beak. Presumably it was herbivorous or omnivorous . Various well-preserved skeletons make Citipati one of the best known oviraptorids.
Finds and naming
Citipati comes from layers of the Djadochta Formation in the Mongolian Aimag Ömnö-Gobi , which can be dated to the middle Campanium (about 80 to 76 million years ago). The Djadochta Formation contains one of the richest known theropod fauna of the entire Mesozoic Era, with the oviraptorids being one of the most common finds.
The holotype material (catalog number IGM 100/978) is an incomplete skeleton with an unusually well-preserved skull that was discovered by an expedition of the American Museum of Natural History and the Mongolian Academy of Sciences in Ukhaa Tolgod . The find was first described in 2001 as Citipati , together with the Oviraptorid Khaan . In 1993 a nest was discovered that contained eggs and a fossil embryo (catalog number IGM 100/971), which in 2001 could be assigned to Citipati . In 1993 a partial skeleton was discovered (catalog number IGM 100/979), which was found in a breeding position above a nest. This fossil, known in the popular press as "Big Mama", was initially considered a specimen of Oviraptor , until it was discovered by Clark et al. Attributed to Citipati in 2001 . Another brooding specimen (catalog number IGM 100/1004) was discovered in 1995 and is known as the "Big Auntie".
Another complete skeleton with skull (catalog number IGM 100/42) was discovered in the Djadochta Formation by Zamyn Khondt (also spelled Dzamin Khong) and is often called Citipati sp. or called "Zamyn-Khondt-Oviraptoride". This as yet unnamed find could be another Citipati species or a new genus. Barsbold originally attributed the find to Oviraptor in 1981 . However, since this skeleton was much more complete than the Oviraptor type material , it formed the basis for scientific studies and popular representations of Oviraptor . Later studies showed differences between Oviraptor and the "Zamyn-Khondt-Oviraptoriden", z. B. in the length of the skull and the upper and lower jaw. Similarities of the intermaxillary bone (premaxillary) and the nasal region suggest that this animal was more closely related to Citipati than to Oviraptor .
The name Citipati is derived from the Sanskrit words citi - " pyre " and pati - "Lord". In Tibetan Buddhist folklore, Citipati were two monks who, immersed in a deep meditative trance, were beheaded by a thief. The Citipati are often depicted as dancing skeletons surrounded by flames - hence the name was used for the well-preserved oviraptorid skeletons. The Artepitheth osmolskae honors the Polish palaeontologist Halszka Osmólska (1930–2008), who has dealt intensively with oviraptorids and other Mongolian theropods.
With a length of up to 3 meters, Citipati was a large oviraptorosaur with a conspicuous crest of the skull. It differed from all other known oviraptorids in a number of skull features; for example, the nostrils were large and teardrop-shaped. Citipati differed from Oviraptor mainly in the shorter skull.
Nests, eggs and embryos
In 1995 a find was first reported showing an oviraptorid brooding over a nest. This fossil, known by the nickname "Big Mama", was described in 1999 and in 2001 assigned to the genus Citipati . Another brooding specimen is known as the "Big Auntie". These specimens were lying on nest mounds when they were discovered, with the limbs spread out and covering each side of the nest. This breeding attitude is otherwise only known in today's birds, which is seen as further evidence of the relationship between birds and theropods. The breeding posture also indicates feathered arms.
Although fossil dinosaur eggs are rare, oviraptorid eggs and in particular, Citipati grade eggs relatively well known. In addition to the skeletons found in association with nests, dozens of isolated oviraptorid nests have been discovered in the Gobi Desert . The eggs are attributed to the Ootaxon Elongatoolithidae ; they are elongated ovals that resemble the eggs of recent ratites in their pattern and shell structure . A complete nest should have contained around 22 eggs, which were arranged in up to three layers in concentric circles. With a size of 18 centimeters, Citipati eggs are the largest eggs that can definitely be assigned to oviraptorids; Eggs associated with Oviraptor are only four inches long.
Ironically, it was the connection with eggs that gave oviraptorids their name, which means something like "egg thieves": The first oviraptorid skeleton to be discovered was the skeleton of an oviraptor sitting on a nesting mound with eggs . Initially, the eggs were assigned to the Ceratopsia Protoceratops , and it was assumed that Oviraptor ate the eggs of the Protoceratops . It was not until 1993, when a Citipati embryo was found inside an egg, that the error could be corrected. Norell et al. , who identified the embryo as an oviraptorid, assigned it to the genus Citipati in 2001 - based on the vertical alignment of the intermaxillary bone (premaxillary), a feature known only from Citipati . The egg that contained the embryo was 12 centimeters smaller than most other known Citipati eggs - however, an exact size estimate is difficult because it is partially eroded and broken into three parts. Otherwise, the egg with the embryo in the shell structure was identical to other oviraptorid eggs. It belonged to an isolated nest that, like other oviraptorid nests, had eggs arranged in a circle. Two undetermined theropod skulls were found associated with the nest.
- ^ Gregory S. Paul : The Princeton Field Guide To Dinosaurs. Princeton University Press, Princeton NJ et al. 2010, ISBN 978-0-691-13720-9 , pp. 153-154, online .
- ^ A b Halszka Osmólska , Philip J. Currie , Rinchen Barsbold : Oviraptorosauria. 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. 165-183, here p. 182.
- ↑ a b c d James M. Clark , Mark A. Norell , Timothy Rowe : Cranial anatomy of Citipati osmolskae (Theropoda, Oviraptorosauria), and a reinterpretation of the holotype of Oviraptor philoceratops (= American Museum Novitates. No. 3364, ISSN 0003 -0082 ). American Museum of Natural History, New York NY 2002, online .
- ↑ a b c d e James M. Clark, Mark A. Norell, Rinchen Barsbold: Two new oviraptorids (Theropoda: Oviraptorosauria), upper Cretaceous Djadokhta Formation, Ukhaa Tolgod, Mongolia. In: Journal of Vertebrate Paleontology. Vol. 21, No. 2, 2001, ISSN 0272-4634 , pp. 209-213, doi : 10.1671 / 0272-4634 (2001) 021 [0209: TNOTOU] 2.0.CO; 2 .
- ↑ a b Michael Mortimer: Oviraptorosauria. In: The Theropod Database. Archived from the original on July 8, 2009 ; Retrieved July 30, 2014 .
- ^ Halszka Osmólska, Teresa Maryańska , Rinchen Barsbold: Oviraptorosauria. In: David B. Weishampel, Peter Dodson, Halszka Osmólska (eds.): The Dinosauria . University of California Press, Berkeley CA et al. 1990, ISBN 0-520-06726-6 , pp. 249-258.
- ↑ Halszka Osmólska, to SVP Honorary Member and Noted Vertebrate Paleontologist, Passed Away March 31. ( Memento of October 27, 2010 in the Internet Archive ) Society of Vertebrate Paleontology. Last accessed on July 30, 2014
- ↑ Mark A. Norell, James M. Clark, Luis M. Chiappe , Demberelyin Dashzeveg: A nesting dinosaur. In: Nature . Vol. 378, No. 6559, 1995, pp. 774-776, doi : 10.1038 / 378774a0 .
- ↑ a b c d James M. Clark, Mark A. Norell, Luis M. Chiappe: An oviraptorid skeleton from the Late Cretaceous of Ukhaa Tolgod, Mongolia, preserved in an avianlike brooding position over an oviraptorid nest (= American Museum Novitates. No. . 3265). American Museum of Natural History, New York NY 1999.
- ^ Gregory S. Paul: Dinosaurs of the air. The evolution and loss of flight in dinosaurs and birds. Johns Hopkins University Press, Baltimore MD et al. 2002, ISBN 0-8018-6763-0 .
- ↑ David J. Varricchio: Reproduction and Parenting. In: Gregory S. Paul: The Scientific American Book of Dinosaurs. St. Martin's Press, New York NY 2000, ISBN 0-312-26226-4 , pp. 279-293.
- ^ Henry Fairfield Osborn : Three new Theropoda, Protoceratops zone, central Mongolia (= American Museum Novitates. No. 144). American Museum of Natural History, New York NY 1924, online .
- ↑ a b Mark A. Norell, James M. Clark, Dashzeveg Demberelyin, bars Bold Rhinchen, Luis M. Chiappe, Amy R. Davidson, Malcolm C. McKenna , pearl Altangerel , Michael J. Novacek : A theropod dinosaur embryo, and the affinities of the Flaming Cliffs Dinosaur eggs. In: Science . Vol. 266, No. 5186, 1994, pp. 779-782, doi : 10.1126 / science.266.5186.779 .