Цитипати: Динозавр-птицелов из мелового периода Азии

Genus of oviraptorid dinosaur

the Buddhist deity

Citipati (; meaning "funeral pyre lord") is a genus of oviraptorid dinosaur that lived in Asia during the Late Cretaceous period, about 75 million to 71 million years ago. It is mainly known from the Ukhaa Tolgod locality at the Djadochta Formation, where the first remains were collected during the 1990s. The genus and type species Citipati osmolskae were named and described in 2001. A second species from the adjacent Zamyn Khondt locality may also exist. Citipati is one of the best known oviraptorids thanks to a number of well preserved specimens, including individuals found in brooding positions atop nests of eggs, though most of them were initially referred to the related Oviraptor. These nesting specimens have helped to solidify the link between non avian dinosaurs and birds. Citipati was among the largest oviraptorids; it is estimated to have been around in length and to have weighed Its skull was highly pneumatized, short, and had a characteristic crest formed by the premaxilla and nasal bones. Both upper and lower jaws were toothless and developed a horny beak. The tail ended in a pygostyle (the fusion of the last caudal vertebrae), which is known to support large rectrices. The taxon is classified as an oviraptorid, a group of very bird like feathered dinosaurs that had robust, parrot like jaws. It is among the oviraptorid species that preserve nesting specimens. Citipati laid elongatoolithid eggs in a circular mound shaped nest, where the parents brooded the eggs by sitting on the nest with their arms covering the nest perimeter. Both arms and tail were covered in long feathers, which likely protected both juveniles and eggs from weather. Citipati may have been an omnivorous oviraptorid, given that the remains of two young individuals of the contemporaneous troodontid Byronosaurus were found in a nest, likely preyed and brought by an adult Citipati to feed its hatchlings. It is also possible that these small Byronosaurus were hatched by the Citipati as a product of nest parasitism.

In 1993, a small fossilized oviraptorid embryo, labelled as specimen IGM 100/971, was discovered in a nest at the Ukhaa Tolgod locality of the highly fossiliferous Djadokhta Formation, Gobi Desert, during the Mongolian Academy of Sciences American Museum of Natural History paleontological project. The expedition also discovered numerous mammal, lizard, theropod, ceratopsian and ankylosaurid fossils remains at this locality, with the addition of at least five types of fossil eggs in nests. The oviraptorid embryo is composed of a nearly complete skeleton and was found in a badly weathered semi circular nest, which also included two perinate (hatchlings or embryos close to hatching) skulls less than of an unknown dromaeosaurid taxon. One of these skulls was reported to preserve portions of an eggshell. Both embryonic oviraptorid and dromaeosaurid skulls were briefly described by the paleontologist Mark A. Norell and colleagues in 1993, who considered this oviraptorid embryo to be closely related to the early named Oviraptor, and also as an evidence supporting that oviraptorids were brooding animals. The two perinates would be later identified as individuals belonging to the troodontid Byronosaurus. During the same year 1993, expeditions of the paleontological project of the Mongolian Academy of Sciences American Museum of Natural History discovered a large adult oviraptorid specimen also from the Ukhaa Tolgod locality of the Djadokhta Formation, in a sublocality known as Ankylosaur Flats. This new specimen was labelled under the specimen number IGM 100/979 and includes a partial skeleton comprising some ribs and partial limbs but lacking the skull, neck and tail. It was found in a nesting pose, sitting atop a nest of elongatoolithid eggs with folded forelimbs and crouched hindlimbs. Similar to the embryonic specimen, IGM 100/979 was considered to be an indeterminate oviraptorid closely related to Oviraptor. The specimen shortly became famous and was nicknamed as "Big Mama" by The New York Times press. A larger and more complete specimen, catalogued as IGM 100/978, was found in 1994 also from the Ankylosaur Flats sublocality by the American Museum–Mongolian Academy of Sciences field expeditions. The specimen was unearthed as a single individual not associated with eggs, and it is represented by a nearly complete skeleton including the skull and much of the postcranial elements. However, it was initially identified as a specimen of Oviraptor. In 1995, the Mongolian Academy of Sciences American Museum of Natural History expedition discovered a second nesting oviraptorid specimen from the Ukhaa Tolgod locality, in a region called Camel's Humps, at the Death Row sublocality. This new specimen was labelled as IGM 100/1004 and nicknamed "Big Auntie". In 2001, the paleontologists James M. Clark, Mark A. Norell and Rinchen Barsbold named the new genus and type species Citipati osmolskae based on the now regarded holotype IGM 100/978, and referred specimens IGM 100/971 (embryo) with 100/979 ("Big Mama"). The generic name, Citipati, is formed from the Sanskrit words citi (meaning funeral pyre) and pati (meaning lord) in reference to the lord of cemeteries in the Tibetan Buddhism folklore, Citipati, which is often depicted as a humanoid skeleton. The specific name, osmolskae, is in honor to the noted Polish paleontologist Halszka Osmólska, whose work dealt extensively with Mongolian theropods.

Though the first specimen of Citipati (IGM 100/971) was briefly reported and discussed, Norell and colleagues in 2001 provided an extensive description of this specimen. As the description was published prior to the formal naming of Citipati, Norell and team tentatively referred this small embryo to a "new large species from Ukhaa Tolgod"—in fact, later known as Citipati osmolskae—based on the shared tall premaxilla morphology among specimens. The more famous IGM 100/979 was extensively described by Clark and team in 1999, also prior to the naming of Citipati. They considered this specimen to be most similar and closely related to Oviraptor than to the other oviraptorids known at that time. Despite being discovered in 1995, the specimen IGM 100/1004 remained partially figured and largely undescribed for years until its formal referral to the taxon Citipati osmolskae in 2018 by Norell and team. the furcula morphology in 2009 by Sterling J. Nesbitt with team, and the caudal vertebrae by W. Scott Persons and colleagues in 2014 who noted the presence of a pygostyle. Subsequent descriptions have been published in 2018 by Norell and team describing and illustrating some cervical vertebrae and uncinate processes, In 2003 Amy Davidson described the process in which the holotype was prepared, later supplemental by Christina Bisulca and team in 2009 describing conservation treatments of broken bones.

The Zamyn Khondt oviraptorid is a well known oviraptorid represented by a single and rather complete specimen (IGM 100/42) collected from the Zamyn Khondt (also spelled as Dzamin Khond) locality of the Djadokhta Formation. Since the type skull and body remains of Oviraptor are crushed and partially preserved, the Zamyn Khondt oviraptorid had become the quintessential depiction of the former, even appearing in scientific literature with the label Oviraptor philoceratops. Clark with team have pointed out that this distinctive looking, tall crested oviraptorid has more features of the skull in common with Citipati than it does with Oviraptor. Though being different in the crest shape of the skull, the Zamyn Khondt oviraptorid is similar to Citipati in the shape of the narial region and premaxilla morphology. They considered this oviraptorid to belong to the genus, however, they could neither confirm nor disregard that this specimen represents a second species of Citipati. Phil Senter with team in 2007 placed it close to neither genus, and in 2020 Gregory F. Funston and colleagues found it to be the sister taxon of Citipati.

Citipati was a large bodied oviraptorid, with the largest individuals being emu sized animals; it has been estimated at in length with a weight between , and was one of the largest known oviraptorosaurs until the description of Gigantoraptor. Based on their humeral lengths, IGM 100/1004 was about 11% larger than IGM 100/979.

The embryo bearing egg was otherwise identical to other oviraptorid eggs in shell structure and was found in an isolated nest, again arranged in a circular pattern. Two skulls belonging to very young or embryonic Byronosaurus were found associated with the same nest as the first Citipati embryo. It is possible that these tiny troodontids were preyed upon by the Citipati to feed its nest. Alternately, Mark Norell suggested that the juvenile troodonts were raiding the Citipati nest, or even that an adult Byronosaurus had laid eggs in a Citipati nest as an act of nest parasitism. The eggs of Citipati are the largest known definitive oviraptorid eggs, at 18 cm. In contrast, eggs associated with Oviraptor are only up to 14 cm long. In 2014, W. Scott Persons and colleagues suggested that oviraptorosaurs were secondarily flightless and several of the traits in their tails may indicate a propensity for display behaviour, such as courtship display. The tail of several oviraptorosaurs and oviraptorids ended in pygostyles, a bony structure at the end of the tail that, at least in modern birds, is used to support a feather fan. Furthermore, the tail was notably muscular and had a pronounced flexibility, which may have aided in courtship movements. In 2002 Clark with team reported a small notch preserved on the right jugal, just beneath the orbit, of the holotype skull of Citipati. This anomaly was likely produced by external damage, leaving a small injury. Other dinosaurs known from Ukhaa Tolgod include alvarezsaurids Kol and Shuvuuia; ankylosaurid Minotaurasaurus; birds Apsaravis and Gobipteryx; dromaeosaurid Tsaagan; fellow oviraptorid Khaan; troodontids Almas and Byronosaurus; and an undescribed protoceratopsid closely related to Protoceratops.