Australovenator
Encyclopedia
Australovenator is a genus
of allosauroid
theropod dinosaur
from late Albian
(Early Cretaceous
)-age rocks of Australia. It is known from partial cranial and postcrania
l remains which were described in 2009 by Scott Hocknull
and colleagues.
Australovenator is based on
AODL 604 (affectionately named "Banjo") a partial skeleton including a left dentary, teeth, partial forelimbs and hindlimbs, a partial right ilium
, ribs, and gastralia
. Australovenator was described in 2009
by paleontologist Scott Hocknull
of the Queensland Museum, and colleagues. The type species
is A. wintonensis, in reference to nearby Winton
. A phylogenetic analysis
found Australovenator to be an allosauroid carnosaurian, with similarities to Fukuiraptor
and carcharodontosaurids
. In the initial analysis, it was shown to be the sister taxon of the Carcharodontosauridae
. More detailed studies found that it formed a clade with several other carcharodontosaurid-like allosaurs, the Neovenatoridae
.
The ankles of Australovenator and Fukuiraptor are similar to the Australian talus bone
known as NMVP
150070 that had previously been identified as belonging to Allosaurus
sp., and it is likely that this bone represents Australovenator or a close relative of it. Alternatively, this bone could belong to an abelisaur
.
AODL 604 was found about 60 kilometres (37.3 mi) northwest of Winton, near Elderslie Station. It was recovered from the lower part of the Winton Formation
, dated to the latest Albian. AODL 604 was found in a clay layer between sandstone
layers, interpreted as an oxbow lake
, or billabong
, deposit. Also found at the site were the type specimen
of the sauropod Diamantinasaurus
, bivalves
, fish, turtles, crocodilia
ns, and plant fossils. The Winton Formation had a faunal assemblage including bivalves, gastropods
, insect
s, the lungfish
Metaceratodus
, turtles, the crocodilia
n Isisfordia
, pterosaur
s, and several types of dinosaurs, such as the sauropods Diamantinasaurus and Wintonotitan
, and unnamed ankylosauria
ns and hypsilophodont
s. Plants known from the formation include fern
s, ginkgo
es, gymnosperm
s, and angiosperms.
Australovenator was a medium-sized allosauroid. According to Hocknull, it was 2 metres (6.6 ft) tall at the hip and 6 metres (19.7 ft) long. Because it was a lightweight predator, he coined it as the "cheetah
of its time". Like other carnosaurians, Australovenator would have been a biped
al carnivore
.
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...
of allosauroid
Allosauroidea
Allosauroidea is a superfamily or clade of theropod dinosaurs which contains four families — the Sinraptoridae, Allosauridae, Carcharodontosauridae, and Neovenatoridae...
theropod dinosaur
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...
from late Albian
Albian
The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous epoch/series. Its approximate time range is 112.0 ± 1.0 Ma to 99.6 ± 0.9 Ma...
(Early Cretaceous
Early Cretaceous
The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...
)-age rocks of Australia. It is known from partial cranial and postcrania
Postcrania
Postcrania[p] in zoology and vertebrate paleontology refers to all or part of the skeleton apart from the skull. Frequently, fossil remains, e.g...
l remains which were described in 2009 by Scott Hocknull
Scott Hocknull
Scott Hocknull is a vertebrate palaeontologist and Senior Curator in Geology at the Queensland Museum in Brisbane. He was the 2002 recipient of the Young Australian of the Year Award....
and colleagues.
Description and history
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
AODL 604 (affectionately named "Banjo") a partial skeleton including a left dentary, teeth, partial forelimbs and hindlimbs, a partial right ilium
Ilium (bone)
The ilium is the uppermost and largest bone of the pelvis, and appears in most vertebrates including mammals and birds, but not bony fish. All reptiles have an ilium except snakes, although some snake species have a tiny bone which is considered to be an ilium.The name comes from the Latin ,...
, ribs, and gastralia
Gastralium
Gastralia are dermal bones found in the ventral body wall of crocodilian and Sphenodon species. They are found between the sternum and pelvis, and do not articulate with the vertebrae...
. Australovenator was described in 2009
2009 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...
by paleontologist Scott Hocknull
Scott Hocknull
Scott Hocknull is a vertebrate palaeontologist and Senior Curator in Geology at the Queensland Museum in Brisbane. He was the 2002 recipient of the Young Australian of the Year Award....
of the Queensland Museum, and colleagues. The type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
is A. wintonensis, in reference to nearby Winton
Winton, Queensland
-Qantas:Winton was one of the founding towns of the Australian airline Qantas. The first board meeting was held at the Winton Club on 10 February 1921.-Waltzing Matilda:...
. A phylogenetic analysis
Cladistics
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...
found Australovenator to be an allosauroid carnosaurian, with similarities to Fukuiraptor
Fukuiraptor
Fukuiraptor was a medium-sized carnivore of the Early Cretaceous that lived in what is now Japan. Scientists first thought it was a member of the Dromaeosauridae, but after studying the fossils they now believe it was related to Allosaurus in the family Neovenatoridae. The type specimen is the...
and carcharodontosaurids
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...
. In the initial analysis, it was shown to be the sister taxon of the Carcharodontosauridae
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...
. More detailed studies found that it formed a clade with several other carcharodontosaurid-like allosaurs, the Neovenatoridae
Neovenatoridae
Neovenatoridae 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...
.
The ankles of Australovenator and Fukuiraptor are similar to the Australian talus bone
Talus bone
-External links:* *...
known as NMVP
Museum Victoria
Museum Victoria is an organisation which operates three major state-owned museums in Melbourne, Victoria, Australia; these are: the Melbourne Museum, the Immigration Museum and Scienceworks. It also manages the Royal Exhibition Building and a storage facility in Melbourne's City of Moreland.Museum...
150070 that had previously been identified as belonging to 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...
sp., and it is likely that this bone represents Australovenator or a close relative of it. Alternatively, this bone could belong to an abelisaur
Abelisaur
Abelisaurs were a group of ceratosaurian dinosaurs which lived in the Southern hemisphere during the Cretaceous period. Some well-known dinosaurs of this group include Abelisaurus, Carnotaurus, and Majungasaurus. They are known for their small arms...
.
Paleobiology
Winton Formation
The Winton Formation is a Cretaceous formation in central-western Queensland, Australia. The sauropod dinosaur Austrosaurus is found in the early Cretaceous Winton formation....
, dated to the latest Albian. AODL 604 was found in a clay layer between sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
layers, interpreted as an oxbow lake
Oxbow lake
An oxbow lake is a U-shaped body of water formed when a wide meander from the main stem of a river is cut off to create a lake. This landform is called an oxbow lake for the distinctive curved shape, named after part of a yoke for oxen. In Australia, an oxbow lake is called a billabong, derived...
, or billabong
Billabong
Billabong is an Australian English word meaning a small lake, specifically an oxbow lake, a section of still water adjacent to a river, cut off by a change in the watercourse. Billabongs are usually formed when the path of a creek or river changes, leaving the former branch with a dead end...
, deposit. Also found at the site were the type specimen
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
of the sauropod Diamantinasaurus
Diamantinasaurus
Diamantinasaurus is a genus of derived titanosaurian dinosaur from late Albian -age rocks of Australia...
, bivalves
Bivalvia
Bivalvia is a taxonomic class of marine and freshwater molluscs. This class includes clams, oysters, mussels, scallops, and many other families of molluscs that have two hinged shells...
, fish, turtles, crocodilia
Crocodilia
Crocodilia is an order of large reptiles that appeared about 84 million years ago in the late Cretaceous Period . They are the closest living relatives of birds, as the two groups are the only known survivors of the Archosauria...
ns, and plant fossils. The Winton Formation had a faunal assemblage including bivalves, gastropods
Gastropoda
The Gastropoda or gastropods, more commonly known as snails and slugs, are a large taxonomic class within the phylum Mollusca. The class Gastropoda includes snails and slugs of all kinds and all sizes from microscopic to quite large...
, insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s, the lungfish
Lungfish
Lungfish are freshwater fish belonging to the Subclass Dipnoi. Lungfish are best known for retaining characteristics primitive within the Osteichthyes, including the ability to breathe air, and structures primitive within Sarcopterygii, including the presence of lobed fins with a well-developed...
Metaceratodus
Metaceratodus
Metaceratodus is an extinct genus of prehistoric sarcopterygian or lobe-finned fish. From the Early Cretaceous of Queensland, Australia.-See also:* Sarcopterygii* List of sarcopterygians* List of prehistoric bony fish...
, turtles, the crocodilia
Crocodilia
Crocodilia is an order of large reptiles that appeared about 84 million years ago in the late Cretaceous Period . They are the closest living relatives of birds, as the two groups are the only known survivors of the Archosauria...
n Isisfordia
Isisfordia
Isisfordia is an extinct genus of crocodyliform closely related to crocodilians that lived during the Middle Cretaceous . Its fossils were discovered in the Winton Formation in Isisford, Queensland, Australia in the mid 1990s...
, pterosaur
Pterosaur
Pterosaurs were flying reptiles of the clade or order Pterosauria. They existed from the late Triassic to the end of the Cretaceous Period . Pterosaurs are the earliest vertebrates known to have evolved powered flight...
s, and several types of dinosaurs, such as the sauropods Diamantinasaurus and Wintonotitan
Wintonotitan
Wintonotitan is a genus of titanosauriform dinosaur from late Albian -age rocks of Australia. It is known from partial postcranial remains.-Description and history:...
, and unnamed ankylosauria
Ankylosauria
Ankylosauria is a group of herbivorous dinosaurs of the order Ornithischia. It includes the great majority of dinosaurs with armor in the form of bony osteoderms. Ankylosaurs were bulky quadrupeds, with short, powerful limbs. They are first known to have appeared in the early Jurassic Period of...
ns and hypsilophodont
Hypsilophodont
Hypsilophodonts were small ornithopod dinosaurs, regarded as fast, herbivorous bipeds on the order of 1–2 meters long . They are known from Asia, Australia, Europe, New Zealand, North America, and South America, from rocks of Middle Jurassic to late Cretaceous age...
s. Plants known from the formation include fern
Fern
A fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants...
s, ginkgo
Ginkgo
Ginkgo , also spelled gingko and known as the Maidenhair Tree, is a unique species of tree with no close living relatives...
es, gymnosperm
Gymnosperm
The gymnosperms are a group of seed-bearing plants that includes conifers, cycads, Ginkgo, and Gnetales. The term "gymnosperm" comes from the Greek word gymnospermos , meaning "naked seeds", after the unenclosed condition of their seeds...
s, and angiosperms.
Australovenator was a medium-sized allosauroid. According to Hocknull, it was 2 metres (6.6 ft) tall at the hip and 6 metres (19.7 ft) long. Because it was a lightweight predator, he coined it as the "cheetah
Cheetah
The cheetah is a large-sized feline inhabiting most of Africa and parts of the Middle East. The cheetah is the only extant member of the genus Acinonyx, most notable for modifications in the species' paws...
of its time". Like other carnosaurians, Australovenator would have been a biped
Biped
Bipedalism is a form of terrestrial locomotion where an organism moves by means of its two rear limbs, or legs. An animal or machine that usually moves in a bipedal manner is known as a biped , meaning "two feet"...
al carnivore
Carnivore
A carnivore meaning 'meat eater' is an organism that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of animal tissue, whether through predation or scavenging...
.