Diamantinasaurus is an extinct genus of non-lithostrotian titanosaurian sauropod from Australia that lived during the early Late Cretaceous, about 94 million years ago. The type species of the genus is D. matildae, first described and named in 2009 by Scott Hocknull and colleagues. Meaning "Diamantina lizard", the name is derived from the location of the nearby Diamantina River and the Greek word sauros, "lizard". The specific epithet is from the Australian song Waltzing Matilda, also the locality of the holotype and paratype. The known skeleton includes most of the forelimb, shoulder girdle, pelvis, hindlimb and ribs of the holotype, and one shoulder bone, a radius and some vertebrae of the paratype.
|Holotype skeleton in (a) right and (b) left views|
Hocknull et al. 2009
Hocknull et al. 2009
The holotype of Diamantinasaurus was first uncovered over four seasons of excavations near Winton, Queensland, Australia. The bones, found alongside the holotype of Australovenator and crocodylomorphs and molluscs. The two dinosaurs found, known from specimens catalogued as AODF 603 and 604 were described in 2009 by Scott Hocknull and his colleagues. Specimen AODF 603 became the basis for the genus Diamantinasaurus, and the species D. matildae. The species name is a reference to the song "Waltzing Matilda", written by Banjo Paterson in Winton, while the generic name is derived from the Diamantina River, running nearby the type locality combined with the Greek sauros, meaning "lizard". AODF 603, the holotype, includes the right scapula, both humeri, right ulna, both incomplete hands, dorsal ribs and gastralia, partial pelvis, and the right hindlimb missing the foot. The paratype, under the same specimen, includes dorsal and sacral vertebrae, the right sternal plate now thought to represent the remainder of a coracoid, a radius, and one manual phalanx. All these bones come from AODL 85, nicknamed the "Matilda Site" at Elderslie Sheep Station, located about 60 km (37 mi) west-northwest from Winton in central Queensland. This locality is in the upper midsection of the Winton Formation, which dates to the Cenomanian of the Late Cretaceous.
The discovery of Diamantinasaurus ended a pause in the discovery of new dinosaurs in Australia, as the first sauropod named in over 75 years. Along with Australovenator, Diamantinasaurus has been nicknamed after the Australian song "Waltzing Matilda", with Australovenator being called "Banjo" and Diamantinasaurus being nicknamed "Matilda". Wintonotitan, also from the site, was dubbed "Clancy". The find was apparently the largest dinosaur discovery in Australia that was documented since that of Muttaburrasaurus in 1981.
An additional specimen, AODF 836, was described in 2016. It includes portions of the skull, including a left squamosal, nearly complete braincase, right surangular, and various fragments. Additionally, the specimen also includes the atlas, axis, five other cervical vertebrae, three dorsal vertebrae, additional dorsal ribs, portions of the hip, and another right scapula.
Diamantinasaurus was relatively small for a titanosaurian, possibly reaching 15–16 m (49–52 ft) in length and 15–20 t (17–22 short tons) in weight. Some of its relatives are known possessed armour osteoderms although is it unknown whether Diamantinasaurus had these. Like other sauropods, Diamantinasaurus would have been a large quadrupedal herbivore. Since the original description, the only major revisions include the misidentification of the "sternal plate", misplacement of manual phalanges III-1 and IV-1 as III-1 and V-1 respectively, and the identification of the missing portion of the fibula.
When it was originally described, Diamantinasaurus was assigned to Lithostrotia incertae sedis. In both phylogenies it was placed in, Diamantinasaurus was either just outside Saltasauridae or the sister taxon of Opisthocoelicaudia within the family. In a 2014 study, it was found that the genus was placed as a lithostrotian in both large phylogenies, in a relatively derived position in Titanosauria. Their first phylogeny was modified from that of Carbadillo and Sander (2014), the matrix being indirectly based on Wilson's 2002 phylogeny. In that cladogram, Diamantinasaurus was found to be sister taxon to Tapuiasaurus, their relationship outside of Saltasauridae. In this phylogeny, the Bremer support for each group was at most 1. Five features of the skeleton supported the placement of Diamantinasaurus in Lithostrotia.
In the same study, the relationships using the Mannion et al. (2013) matrix were tested. These resolved with Diamantinasaurus as a saltasaurid, sister to Opisthocoelicaudia, with Dongyangosaurus as the next closest. Two characters were found to support the placement of Diamantinasaurus in Lithostrotia, and a third could not be evaluated.
In 2011, the smallest positively identified titanosaur embryo was described. Although it was uncovered in Mongolia, the embryo shares the most features with Diamantinasaurus and Rapetosaurus. The embryo, from a relatively spherical 87.07–91.1 millimetres (3.428–3.587 in) egg, was identified as persisting to a lithostrotian. The embryo was slightly robust, intermediate between the robustness of Rapetosaurus and Diamantinasaurus. The egg is part of an entire nesting site for lithostrotian titanosaurs. Dating of the region also suggests that this egg predates those of Auca Mahuevo in Argentina, and the eggs were laid in the Early Cretaceous.
Diamantinasaurus was found about 60 kilometres (37 mi) northwest of Winton, near Elderslie Station. It was recovered from the fossil-rich section of the Winton Formation, which can be dated to approximately 93.9 million years ago. Diamantinasaurus was found in a clay layer between sandstone layers, interpreted as an oxbow lake deposit. Also found at the site was Australovenator, which was directly associated with Diamantinasaurus, bivalves, fish, turtles, crocodilians, and various plants. The Winton Formation had a faunal assemblage including bivalves, gastropods, insects, the lungfish Metaceratodus, turtles, the crocodilian Isisfordia, pterosaurs, and several types of dinosaurs, such as the aforementioned Australovenator, the sauropods Wintonotitan, Savannasaurus, and Austrosaurus, and unnamed ankylosaurians and hypsilophodonts. Diamantinasaurus bones can be distinguished from other sauropods because of the overall robusticity as well as multiple specific features. Plants known from the formation include ferns, ginkgoes, gymnosperms, and angiosperms.
Aeolosaurini is an extinct clade of titanosaurian dinosaurs known from the late Cretaceous period of Argentina and Brazil. Thomas Holtz (2011) assigned Adamantisaurus, Aeolosaurus, Gondwanatitan, Muyelensaurus, Panamericansaurus, Pitekunsaurus and Rinconsaurus to Aeolosauridae. Rodrigo M. Santucci and Antonio C. de Arruda-Campos (2011) in their cladistic analysis found Aeolosaurus, Gondwanatitan, Maxakalisaurus, Panamericansaurus and Rinconsaurus to be aeolosaurids.Australian Age of Dinosaurs
Australian Age of Dinosaurs Ltd (AAOD) is a not for profit organisation located in Winton, Queensland and founded by David Elliott and Judy Elliott in 2002. The organisation's activities include operation of the Australian Age of Dinosaurs Museum of Natural History (the Museum) which holds annual dinosaur digs in the Winton Formation of western Queensland and oversees the year-round operation of Australia's most productive dinosaur fossil preparation laboratory. Since 2005, the AAOD Museum has accumulated the largest collection of Australian dinosaur fossils in the world and holds the holotype specimens of Diamantinasaurus matildae ("Matilda"), Savannasaurus elliottorum ("Wade"), and Australovenator wintonensis ("Banjo"), Australia's most complete theropod skeleton. The museum is open to the public daily from April to end September and open six days (closed Sundays) from October to end March. The site of the Museum was designated a Dark-sky preserve, the first International Dark-Sky Sanctuary in Australia, in 2019.Australovenator
Australovenator (meaning "southern hunter") is a genus of megaraptorid theropod dinosaur from Cenomanian (Late Cretaceous)-age Winton Formation (dated to 95 million years ago) of Australia. It is known from partial cranial and postcranial remains which were described in 2009 by Scott Hocknull and colleagues, although additional descriptions and analyses continue to be published. It is the most complete predatory dinosaur discovered in Australia.Diplodocinae
Diplodocinae is an extinct subfamily of diplodocid sauropods that existed from the Late Jurassic to Early Cretaceous of North America, Europe and South America, about 161.2 to 136.4 million years ago. Genera within the subfamily include Tornieria, Supersaurus, Leinkupal, Galeamopus, Diplodocus, Kaatedocus and Barosaurus.Cladogram of the Diplodocidae after Tschopp, Mateus, and Benson (2015).Ferganasaurus
Ferganasaurus was a genus of dinosaur first formally described in 2003 by Alifanov and Averianov. The type species is Ferganasaurus verzilini. It was a sauropod similar to Rhoetosaurus. The fossils were discovered in 1966 in Kyrgyzstan from the Balabansai Formation and date to the Callovian stage of the Middle Jurassic.Flagellicaudata
Flagellicaudata is a clade of Dinosauria. It belongs to Sauropoda and includes two families, the Dicraeosauridae and the Diplodocidae.Gravisauria
Gravisauria is a clade of sauropod dinosaurs consisting of some genera, Vulcanodontidae and Eusauropoda.Huangshanlong
Huangshanlong is a genus of mamenchisaurid dinosaurs native to the Anhui province of China. It contains a single species, Huangshanlong anhuiensis. H. anhuiensis represents, along with Anhuilong and Wannanosaurus, one of three dinosaurs fround in Anhui province.Kaijutitan
Kaijutitan (meaning "Kaiju titan" after the type of Japanese movie monsters) is a genus of basal titanosaur dinosaur from the Sierra Barrosa Formation from Neuquén Province in Argentina. The type and only species is Kaijutitan maui.List of Australian and Antarctic dinosaurs
This is a list of dinosaurs whose remains have been recovered from Australia or Antarctica.Lithostrotia
Lithostrotia is a clade of derived titanosaur sauropods that lived during the Early Cretaceous and Late Cretaceous. The group was defined by Unchurch et al. in 2004 as the most recent common ancestor of Malawisaurus and Saltasaurus and all the descendants of that ancestor. Lithostrotia is derived from the Ancient Greek lithostros, meaning "inlaid with stones", referring to the fact that many known lithostrotians are preserved with osteoderms. However, osteoderms are not a distinguishing feature of the group, as the two noted by Unchurch et al. include caudal vertebrae with strongly concave front faces (procoely), although the farthest vertebrae are not procoelous.Nemegtosauridae
Nemegtosauridae is a family of titanosaurian sauropod dinosaurs based originally on two late Cretaceous Mongolian species known only from their diplodocid-like skulls: Nemegtosaurus and Quaesitosaurus.Ruyangosaurus
Ruyangosaurus (Ruyang County lizard) is a genus of titanosauriform sauropod dinosaur recovered from the Early Cretaceous Haoling Formation of China. The type species is R. giganteus, described in 2009 by Lü Junchang et al. Along with Huanghetitan and Daxiatitan, Ruyangosaurus is among the largest dinosaurs discovered in Cretaceous Asia.Saltasaurinae
Saltasaurinae is a subfamily of titanosaurian sauropods known from the late Cretaceous period of South America, India and Madagascar. They are considered to be the most derived of all sauropods.Savannasaurus
Savannasaurus is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous of Queensland, Australia, containing one species, Savannasaurus elliottorum, named in 2016 by Poropat et al. The only known specimen was originally nicknamed "Wade". The holotype is held on display at the Australian Age of Dinosaurs museum.Tambatitanis
Tambatitanis is an extinct genus of titanosauriform dinosaur from the Early Cretaceous (probably early Albian) of Japan. It is known from a single type species, Tambatitanis amicitiae. It was probably around 14 meters long and its mass was estimated at some 4 tonnes. It was a basal titanosauriform and possibly belonged to the Euhelopodidae.Tendaguria
Tendaguria ( TEN-də-GEWR-ee-ə; meaning "the Tendaguru one") is a genus of herbivorous sauropod dinosaur from the Late Jurassic of Tanzania.Titanosauria
Titanosaurs (members of the group Titanosauria) were a diverse group of sauropod dinosaurs which included Saltasaurus and Isisaurus of Africa, Asia, South America, Europe and Australia. The titanosaurs were the last surviving group of long-necked sauropods, with taxa still thriving at the time of the extinction event at the end of the Cretaceous. The group includes the largest land animals known to have existed, such as Patagotitan—estimated at 37 m (121 ft) long with a weight of 69 tonnes (76 tons)—and the comparably sized Argentinosaurus and Puertasaurus from the same region. The group's name alludes to the mythological Titans of Ancient Greece, via the type genus (now considered a nomen dubium) Titanosaurus. Together with the brachiosaurids and relatives, titanosaurs make up the larger clade Titanosauriformes.Wintonotitan
Wintonotitan (meaning "Winton titan") is a genus of titanosauriform dinosaur from late Albian (Early Cretaceous)-age Winton Formation of Australia. It is known from partial postcranial remains.