Shaochilong Temporal range: Late Cretaceous, | |
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Restoration of Shaochilong preying on Sinornithomimus | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | Saurischia |
Clade: | Theropoda |
Family: | † Carcharodontosauridae |
Genus: | † Shaochilong Brusatte et al., 2009 |
Species: | †S. maortuensis |
Binomial name | |
†Shaochilong maortuensis (Hu, 1964) | |
Synonyms | |
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Shaochilong (meaning "shark toothed dragon") is an extinct genus of carcharodontosaurid dinosaur from the mid-Cretaceous (Late Cenomanian to the end of the Turonian stage) Ulansuhai Formation of China (about 92 million years ago). The type species, S. maortuensis, was originally named Chilantaisaurus maortuensis, but was re-described and reclassified in 2009. [1] [2] It was one of the last known carcharodontosaurids to walk the earth. Alongside Mapusaurus from Argentina, they were the only members of the family to live until the end of the Turonian epoch.
The material referred to Shaochilong, IVPP V.2885.1-7, consisted of skull fragments (a braincase, partial skull roof, quadrates, and a right maxilla), axis and six caudal vertebrae. A fragmentary left maxilla was also referred to the species, although it has apparently gone missing as of 2009. Although these are believed to belong to a single individual, a lectotype was established in 2010 to accommodate for the possibility that the specimens came from multiple individuals. The lectotype consists of the braincase (IVPP V.2885.1) and partial skull roof (IVPP V.2885.2). [2] All of these specimens were discovered in Inner Mongolia and described by Hu in 1964 as a species of Chilantaisaurus . [3] The genus was informally named "Alashansaurus" by Chure in 2000.
Chure (2002) and Rauhut (2001) suggested that it did not belong to that genus, and was probably a primitive coelurosaur. [4] However, a re-description by Brusatte and colleagues in 2009 found that it was a carcharodontosaurid, the first recognized from Asia. This re-description also provided a new genus name. [1] A more comprehensive description and discussion was published the following year. [2]
The individual which IVPP V2885.1 belonged to was probably adult or nearly adult individual, due to the fusion of many elements of the braincase. Shaochilong's length – based on the length of the maxillary tooth row – is estimated at 5 to 6 metres (16 to 20 ft). Estimated length of the femur is 61.5 cm which suggests the whole animal weighed approximately 500 kilograms (1,100 lb). This made Shaochilong an uncharacteristically small carcharodontosaurid, in contrast with other members of the family, which were among the largest carnivorous animals on earth. Nevertheless, as an unambiguous example of a fairly large carnosaur in middle Cretaceous Asia, it provides information on the ecosystem of this setting and is evidence that carcharodontosaurids persisted through the middle cretaceous and that large tyrannosaurids (such as Tyrannosaurus ) did not dominate Laurasia until the very end of the Cretaceous. [2]
According to the proportions of its maxilla, Shaochilong was a relatively short-faced carcharodontosaur. In combination with its comparatively small size, it could have had a unique ecological role in comparison to other members of the family. [2]
Shaochilong can be distinguished from other carcharodontosaurids due to having the following autapomorphies: [2]
Phylogenetic analysis performed by Brusatte and coworkers indicate that Shaochilong is deeply nested within the carcharodontosaurids, the most derived group among the allosauroids. Shaochilong appears to be more closely related to the Gondwanan carcharodontosaurids ( Tyrannotitan , Carcharodontosaurus , Mapusaurus , Giganotosaurus ) than the Laurasian ones (such as Neovenator and Acrocanthosaurus ). Shaochilong is the youngest known Laurasian allosauroid suggesting that basal tetanurans not tyrannosaurids, were still the dominant group of large-bodied theropods in Laurasian during the Mid-Cretaceous and that the rise of tyrannosaurids as the dominant group of large terrestrial predators was sudden and confined to the very end of the Cretaceous.
The following cladogram after Novas et al., 2013, shows the position of Shaochilong within Carcharodontosauridae. [5]
Cau (2024) recovered Shaochilong in a clade with Labocania and as a close relative to Lajasvenator , Meraxes , and referred cranial material of a " Carcharodontosaurus iguidensis " specimen. [6]
Carcharodontosauridae |
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Giganotosaurus is a genus of theropod dinosaur that lived in what is now Argentina, during the early Cenomanian age of the Late Cretaceous period, approximately 99.6 to 95 million years ago. The holotype specimen was discovered in the Candeleros Formation of Patagonia in 1993 and is almost 70% complete. The animal was named Giganotosaurus carolinii in 1995; the genus name translates to "giant southern lizard", and the specific name honors the discoverer, Ruben Carolini. A dentary bone, a tooth, and some tracks, discovered before the holotype, were later assigned to this animal. The genus attracted much interest and became part of a scientific debate about the maximum sizes of theropod dinosaurs.
Acrocanthosaurus is a genus of carcharodontosaurid dinosaur that existed in what is now North America during the Aptian and early Albian stages of the Early Cretaceous, from 113 to 110 million years ago. Like most dinosaur genera, Acrocanthosaurus contains only a single species, A. atokensis. It had a continent-wide range, with fossil remains known from the U.S. states of Oklahoma, Texas, and Wyoming in the west, and Maryland in the east.
Carcharodontosaurus is a genus of carnivorous theropod dinosaur that lived in North Africa from about 100 to 94 million years ago during the Cenomanian stage of the Late Cretaceous. Two teeth of the genus, now lost, were first described from Algeria by French paleontologists Charles Depéret and Justin Savornin as Megalosaurus saharicus. A partial skeleton was collected by crews of German paleontologist Ernst Stromer during a 1914 expedition to Egypt. Stromer did not report the Egyptian find until 1931, in which he dubbed the novel genus Carcharodontosaurus, making the type species C. saharicus. Unfortunately, this skeleton was destroyed during the Second World War. In 1995 a nearly complete skull of C. saharicus, the first well-preserved specimen to be found in almost a century, was discovered in the Kem Kem Beds of Morocco; it was designated the neotype in 1996. Fossils unearthed from the Echkar Formation of northern Niger were described and named as another species, C. iguidensis, in 2007.
Carnosauria is an extinct group of carnivorous theropod dinosaurs that lived during the Jurassic and Cretaceous periods.
Tetanurae is a clade that includes most theropod dinosaurs, including megalosauroids, allosauroids, tyrannosauroids, ornithomimosaurs, compsognathids and maniraptorans. Tetanurans are defined as all theropods more closely related to modern birds than to Ceratosaurus and contain the majority of predatory dinosaur diversity. Tetanurae likely diverged from its sister group, Ceratosauria, during the late Triassic. Tetanurae first appeared in the fossil record by the Early Jurassic about 190 mya and by the Middle Jurassic had become globally distributed.
Neovenator is a genus of carcharodontosaurian theropod dinosaur. It is known from several skeletons found in the Early Cretaceous (Hauterivian-Barremian) Wessex Formation on the south coast of the Isle of Wight, southern England. It is one of the best known theropod dinosaurs from the Early Cretaceous of Europe.
Carcharodontosauridae is a group of carnivorous theropod dinosaurs. In 1931, Ernst Stromer named Carcharodontosauridae as a family, which, in modern paleontology, indicates a clade within Carnosauria. Carcharodontosaurids include some of the largest land predators ever known: Giganotosaurus, Mapusaurus, Carcharodontosaurus, and Tyrannotitan all rivaled Tyrannosaurus in size. Estimates give a maximum weight of 8–10 metric tons for the largest carcharodontosaurids, while the smallest carcharodontosaurids were estimated to have weighed at least 500 kilograms (1,100 lb).
Rugops is a monospecific genus of basal abelisaurid theropod dinosaur from Niger that lived during the Late Cretaceous period in what is now the Echkar Formation. The type and only species, Rugops primus, is known only from a partial skull. It was named and described in 2004 by Paul Sereno, Jeffery Wilson and Jack Conrad. Rugops has an estimated length of 4.4–5.3 metres and weight of 410 kilograms. The top of its skull bears several pits which correlates with overlaying scale and the front of the snout would have had an armour-like dermis.
Alioramus is a genus of tyrannosaurid theropod dinosaurs from the Late Cretaceous period of Asia. It currently contains two species. The type species, A. remotus is known from a partial skull and three foot bones recovered from the Mongolian Nemegt Formation, which was deposited in a humid floodplain about 70 million years ago. These remains were named and described by Soviet paleontologist Sergei Kurzanov in 1976. A second species, A. altai, known from a much more complete skeleton also from the Nemegt Formation, was named and described by Stephen L. Brusatte and colleagues in 2009. Its relationships to other tyrannosaurid genera were at first unclear, with some evidence supporting a hypothesis that Alioramus was closely related to the contemporary species Tarbosaurus bataar. However, the discovery of Qianzhousaurus indicates that it belongs to a distinct branch of tyrannosaurs, namely the tribe Alioramini.
Chilantaisaurus is a genus of large theropod dinosaur, possibly a neovenatorid or a primitive coelurosaur, from the Late Cretaceous Ulansuhai Formation of China. The type species, C. tashuikouensis, was described by Hu in 1964.
Labocania is a genus of carnivorous theropod dinosaur of uncertain affinities from Baja California, Mexico, which lived 93.6 million years ago, in the Cenomanian-Turonian stage of the late Cretaceous Period.
Megaraptor is a genus of large theropod dinosaur that lived in the ages of the Late Cretaceous. Its fossils have been discovered in the Patagonian Portezuelo Formation of Argentina, South America. Initially thought to have been a giant dromaeosaur-like coelurosaur, it was classified as a neovenatorid allosauroid in previous phylogenies, but more recent phylogeny and discoveries of related megaraptoran genera has placed it as either a basal tyrannosauroid or a basal coelurosaur with some studies still considering it a neovenatorid.
Sinosaurus is an extinct genus of theropod dinosaur which lived during the Early Jurassic Period. It was a bipedal carnivore approximately 5.5 metres (18 ft) in length and 300 kilograms (660 lb) in body mass. Fossils of the animal were found at the Lufeng Formation, in the Yunnan Province of China.
Mapusaurus was a giant carcharodontosaurid carnosaurian dinosaur from the early Late Cretaceous, approximately 93.9 to 89.6 million years ago, of what is now Argentina.
Erectopus is an extinct genus of basal allosauroid theropod from the Early Cretaceous La Penthiève Beds Formation of France and also possibly the Cernavodă Formation of southern Romania. The type species is E. superbus, which was initially known as a species of Megalosaurus.
Allosauroidea is a superfamily or clade of theropod dinosaurs which contains four families — the Metriacanthosauridae, Allosauridae, Carcharodontosauridae, and Neovenatoridae. Allosauroids, alongside the family Megalosauroidea, were among the apex predators that were active during the Middle Jurassic to Late Cretaceous periods. The most famous and best understood allosauroid is the North American genus Allosaurus.
Neovenatoridae is a proposed clade of carcharodontosaurian dinosaurs uniting some primitive members of the group such as Neovenator with the Megaraptora, a group of theropods with controversial affinities. Other studies recover megaraptorans as basal coelurosaurs unrelated to carcharodontosaurs. Other theropods with uncertain affinities such as Gualicho, Chilantaisaurus and Deltadromeus are also sometimes included.
Proceratosauridae is a family or clade of tyrannosauroid theropod dinosaurs from the Middle Jurassic to the Early Cretaceous.
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