Carnosauria
Encyclopedia
Carnosauria is a group of large predatory dinosaur
s that lived during the Jurassic
and Cretaceous
periods. While it originally contained a wide assortment of giant theropods that were not closely related, the group has since been defined to encompass only the allosaurs
and their closest kin. Recently, scientists have discovered some very large carnosaurs in the carcharodontosaurid
family such as Giganotosaurus
and Tyrannotitan
which are among the largest known predatory dinosaurs.
Distinctive characteristics of carnosaurs include large eyes, a long narrow skull
and modifications of the legs and pelvis
such as the thigh (femur
) being longer than the shin (tibia
).
analysis defines Carnosauria as those tetanurans
sharing a more recent common ancestor with Allosaurus
than with modern birds.
. Most former carnosaurs were reclassified as more primitive theropods. Others were placed in Coelurosauria
if they were more closely related to birds, like the tyrannosaurids. Other former carnosaurs include the megalosaurid
s, the spinosaurids, and the ceratosaurs. Even non-dinosaurs have been considered carnosaurs, such as the rauisuchia
n Teratosaurus
.
Allosauroidea was originally proposed by Phil Currie
and Zhao (1993; p. 2079), and later used as an undefined stem-based taxon by Paul Sereno
(1997). Sereno (1998; p. 64) was the first to provide a stem-based definition for the Allosauroidea, defining the clade as "All neotetanurans closer to Allosaurus than to Neornithes." Kevin Padian
(2007) used a node-based definition, defined the Allosauroidea as Allosaurus, Sinraptor
, their most recent common ancestor
, and all of its descendants. Thomas R. Holtz and colleagues (2004; p. 100) and Phil Currie and Ken Carpenter
(2000), among others, have followed this node-based definition. However, in some analyses (such as Currie & Carpenter, 2000), the placement of the carcharodontosaurids relative to the allosaurids and sinraptorids is uncertain, and therefore it is uncertain whether or not they are allosauroids (Currie & Carpenter, 2000).
The cladogram
presented here follows the 2010 analysis by Benson, Carrano and Brusatte.
, the tooth was compared to another allosauroid tooth from Portugal
that measured 12.7 centimetres (5 in). Analysis led to the conclusion that CPT-1980 is the largest theropod tooth ever discovered in Spain
. The theropod most likely measured between 6 and 15 meters long. This tooth was discovered by locals near Riodeva, Teruel in the Villar del Arzobispo Formation, more specifically known as RD-39. The rocks have been dated to the Tithonian
-Berriasian
stages (Late Jurassic
-Early Cretaceous
).
generic
name, attributed to Friedrich von Huene
, 1929, that is sometimes seen in lists of dinosaurs. It is probably a typographical error; von Huene intended to assign indeterminate remains to Carnosauria incertae sedis
, but at some point in the process of publication, the text was revised to make it appear that he was creating a new generic name "Carnosaurus" (as described by George Olshevsky
in a 1999 post to the Dinosaur Mailing List). The name is undescribed and has not been used seriously.
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
s that lived during the Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
and Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
periods. While it originally contained a wide assortment of giant theropods that were not closely related, the group has since been defined to encompass only the allosaurs
Allosauroidea
Allosauroidea is a superfamily or clade of theropod dinosaurs which contains four families — the Sinraptoridae, Allosauridae, Carcharodontosauridae, and Neovenatoridae...
and their closest kin. Recently, scientists have discovered some very large carnosaurs in the carcharodontosaurid
Carcharodontosauridae
Carcharodontosaurids were a group of carnivorous theropod dinosaurs. In 1931 Ernst Stromer named Carcharodontosauridae as a family, in modern paleontology this name indicates a clade within Carnosauria...
family such as Giganotosaurus
Giganotosaurus
Giganotosaurus is a genus of carcharodontosaurid dinosaur that lived around 97 million years ago during the early Cenomanian stage of the Late Cretaceous Period. It included some of the largest known terrestrial carnivores, slightly larger than the largest Tyrannosaurus, but smaller than the...
and Tyrannotitan
Tyrannotitan
Tyrannotitan is a genus of huge bipedal carnivorous dinosaur of the carcharodontosaurid family from the Aptian stage of the early Cretaceous period, discovered in Argentina. It is closely related to other giant predators like Giganotosaurus and Carcharodontosaurus...
which are among the largest known predatory dinosaurs.
Distinctive characteristics of carnosaurs include large eyes, a long narrow skull
Skull
The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...
and modifications of the legs and pelvis
Pelvis
In human anatomy, the pelvis is the lower part of the trunk, between the abdomen and the lower limbs .The pelvis includes several structures:...
such as the thigh (femur
Femur
The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...
) being longer than the shin (tibia
Tibia
The tibia , shinbone, or shankbone is the larger and stronger of the two bones in the leg below the knee in vertebrates , and connects the knee with the ankle bones....
).
Systematics
Modern cladisticCladistics
Cladistics is a method of classifying species of organisms into groups called clades, which consist of an ancestor organism and all its descendants . For example, birds, dinosaurs, crocodiles, and all descendants of their most recent common ancestor form a clade...
analysis defines Carnosauria as those tetanurans
Tetanurae
Tetanurae, or "stiff tails", is a clade that includes most theropod dinosaurs, as well as birds. Tetanurans first appear during the early or middle Jurassic Period.-Definition:...
sharing a more recent common ancestor with Allosaurus
Allosaurus
Allosaurus is a genus of large theropod dinosaur that lived 155 to 150 million years ago during the late Jurassic period . The name Allosaurus means "different lizard". It is derived from the Greek /allos and /sauros...
than with modern birds.
Taxonomy
Carnosauria has traditionally been used as a dumping ground for all large theropods, but analysis in the 1980s and 1990s revealed that other than size, the group shared very few characteristics, making it polyphyleticPolyphyly
A polyphyletic group is one whose members' last common ancestor is not a member of the group.For example, the group consisting of warm-blooded animals is polyphyletic, because it contains both mammals and birds, but the most recent common ancestor of mammals and birds was cold-blooded...
. Most former carnosaurs were reclassified as more primitive theropods. Others were placed in Coelurosauria
Coelurosauria
Coelurosauria is the clade containing all theropod dinosaurs more closely related to birds than to carnosaurs. In the past, it was used to refer to all small theropods, although this classification has been abolished...
if they were more closely related to birds, like the tyrannosaurids. Other former carnosaurs include the megalosaurid
Megalosaurid
Megalosauridae was a family of relatively primitive tetanuran theropod dinosaurs, order Saurischia. They were small-to-large carnivores with sharp teeth and three claws on each hand. Some members of this group were Megalosaurus, Eustreptospondylus, Streptospondylus and Torvosaurus...
s, the spinosaurids, and the ceratosaurs. Even non-dinosaurs have been considered carnosaurs, such as the rauisuchia
Rauisuchia
Rauisuchia is a group of predatory and mostly large Triassic archosaurs. As a clade, Rauisuchia includes these Triassic forms and all crocodylomorphs, which are descendants of Triassic rauisuchians. The group in its traditional sense is paraphyletic, because it does not include crocodylomorph...
n Teratosaurus
Teratosaurus
Teratosaurus was a genus of rauisuchian known from the Triassic Stubensandstein of Germany...
.
- Infraorder Carnosauria
- BecklespinaxBecklespinaxBecklespinax is a genus of large theropod dinosaur based on a type specimen of three tall-spined vertebrae found in 1884 in Sussex, England by the fossil collector Samuel H. Beckles. The fossils are believed to have been from the Early Cretaceous....
- ErectopusErectopusErectopus is an allosauroid theropod from the Lower Cretaceous of France.The material comprising the type series was discovered in the late 19th century from the Phosphate-bearing beds of La Penthèive at Louppy-le-Château in eastern France, which have also produced remains of plesiosaurs,...
- GasosaurusGasosaurusGasosaurus was a tetanuran dinosaur discovered in Dashanpu, China. The scientific name, meaning "Gas Lizard", honours the gasoline company that found the Dashanpu fossil quarry in Sichuan Province, now named as the Lower Shaximiao Formation. It had strong legs but short arms, and like most...
- SiamotyrannusSiamotyrannusSiamotyrannus is a genus of theropod dinosaur from the early Cretaceous . It is known from a partial skeleton which includes part of the pelvis, the sacrum, and a number of vertebrae. The fossils were found in 1993 by Somchai Traimwichanon in the Sao Khua Formation of northeastern Thailand...
- Superfamily AllosauroideaAllosauroideaAllosauroidea is a superfamily or clade of theropod dinosaurs which contains four families — the Sinraptoridae, Allosauridae, Carcharodontosauridae, and Neovenatoridae...
- Family Allosauridae
- Family CarcharodontosauridaeCarcharodontosauridaeCarcharodontosaurids were a group of carnivorous theropod dinosaurs. In 1931 Ernst Stromer named Carcharodontosauridae as a family, in modern paleontology this name indicates a clade within Carnosauria...
- Family NeovenatoridaeNeovenatoridaeNeovenatoridae is a family of large carnivorous dinosaurs. The group is a branch of the allosauroids, a large group of carnosaurs that also includes the sinraptorids, carcharodontosaurids, and allosaurids...
- Family SinraptoridaeSinraptoridaeSinraptorids were a family of carnivorous theropod dinosaurs. They tended to be large predators, some growing to sizes of . Sinraptorids are carnosaurs, and many were initially classified within Megalosauridae or Allosauridae prior to recent analysis...
- Becklespinax
Phylogeny
The cladeClade
A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...
Allosauroidea was originally proposed by Phil Currie
Phil Currie
Philip John Currie, AOE is a Canadian palaeontologist and museum curator who helped found the Royal Tyrrell Museum of Palaeontology in Drumheller, Alberta and is now a professor at the University of Alberta in Edmonton...
and Zhao (1993; p. 2079), and later used as an undefined stem-based taxon by Paul Sereno
Paul Sereno
Paul Callistus Sereno is an American paleontologist from the University of Chicago who discovered several new dinosaur species on several continents. He has conducted excavations at sites as varied as Inner Mongolia, Argentina, Morocco, and Niger...
(1997). Sereno (1998; p. 64) was the first to provide a stem-based definition for the Allosauroidea, defining the clade as "All neotetanurans closer to Allosaurus than to Neornithes." Kevin Padian
Kevin Padian
Kevin Padian is a Professor of Integrative Biology at the University of California, Berkeley, Curator of Paleontology, University of California Museum of Paleontology and President of the National Center for Science Education. Padian's area of interest is in vertebrate evolution, especially the...
(2007) used a node-based definition, defined the Allosauroidea as Allosaurus, Sinraptor
Sinraptor
Sinraptor is a genus of theropod dinosaur from the Late Jurassic. The name Sinraptor comes from the Latin prefix "Sino", meaning Chinese, and "Raptor" meaning thief. The specific name dongi honours Dong Zhiming...
, their most recent common ancestor
Most recent common ancestor
In genetics, the most recent common ancestor of any set of organisms is the most recent individual from which all organisms in the group are directly descended...
, and all of its descendants. Thomas R. Holtz and colleagues (2004; p. 100) and Phil Currie and Ken Carpenter
Kenneth Carpenter
Kenneth Carpenter is a paleontologist. He is the museum director of the USU Eastern Prehistoric Museum and author or co-author of a number of books on dinosaurs and Mesozoic life...
(2000), among others, have followed this node-based definition. However, in some analyses (such as Currie & Carpenter, 2000), the placement of the carcharodontosaurids relative to the allosaurids and sinraptorids is uncertain, and therefore it is uncertain whether or not they are allosauroids (Currie & Carpenter, 2000).
The cladogram
Cladogram
A cladogram is a diagram used in cladistics which shows ancestral relations between organisms, to represent the evolutionary tree of life. Although traditionally such cladograms were generated largely on the basis of morphological characters, DNA and RNA sequencing data and computational...
presented here follows the 2010 analysis by Benson, Carrano and Brusatte.
CPT-1980
CPT-1980 is the museum catalog number for an isolated, 9.83 centimetres (3.9 in), allosauroid tooth crown currently housed at the Museo Fundación Conjunto Paleontológico de Teruel. In 20092009 in paleontology
-Anomalocaridids:-Arachnids:-Insects:-Cephalopods:Three new species of extinct Octopoda discovered in 2009. The species - Keuppia hyperbolaris, Keuppia levante, and Styletoctopus annae - lived about 95 million years ago, and bear a strong resemblance to modern octopuses, suggesting that the...
, the tooth was compared to another allosauroid tooth from Portugal
Portugal
Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...
that measured 12.7 centimetres (5 in). Analysis led to the conclusion that CPT-1980 is the largest theropod tooth ever discovered in Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
. The theropod most likely measured between 6 and 15 meters long. This tooth was discovered by locals near Riodeva, Teruel in the Villar del Arzobispo Formation, more specifically known as RD-39. The rocks have been dated to the Tithonian
Tithonian
In the geologic timescale the Tithonian is the latest age of the Late Jurassic epoch or the uppermost stage of the Upper Jurassic series. It spans the time between 150.8 ± 4 Ma and 145.5 ± 4 Ma...
-Berriasian
Berriasian
In the geological timescale, the Berriasian is an age or stage of the Early or Lower Creteceous. It is the oldest or lowest subdivision in the entire Cretaceous. It spanned between 145.5 ± 4.0 Ma and 140.2 ± 3.0 Ma...
stages (Late Jurassic
Late Jurassic
The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 161.2 ± 4.0 to 145.5 ± 4.0 million years ago , which is preserved in Upper Jurassic strata. In European lithostratigraphy, the name "Malm" indicates rocks of Late Jurassic age...
-Early Cretaceous
Early Cretaceous
The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...
).
"Carnosaurus"
"Carnosaurus" is an informalNomen nudum
The phrase nomen nudum is a Latin term, meaning "naked name", used in taxonomy...
generic
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
name, attributed to Friedrich von Huene
Friedrich von Huene
Friedrich von Huene was a German paleontologist who named more dinosaurs in the early 20th century than anyone else in Europe.-Biography:...
, 1929, that is sometimes seen in lists of dinosaurs. It is probably a typographical error; von Huene intended to assign indeterminate remains to Carnosauria incertae sedis
Incertae sedis
, is a term used to define a taxonomic group where its broader relationships are unknown or undefined. Uncertainty at specific taxonomic levels is attributed by , , and similar terms.-Examples:*The fossil plant Paradinandra suecica could not be assigned to any...
, but at some point in the process of publication, the text was revised to make it appear that he was creating a new generic name "Carnosaurus" (as described by George Olshevsky
George Olshevsky
George Olshevsky is a freelance editor, writer, publisher, amateur paleontologist, and mathematician living in San Diego, California.Olshevsky maintains the comprehensive online Dinosaur Genera List...
in a 1999 post to the Dinosaur Mailing List). The name is undescribed and has not been used seriously.