Taurovenator

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Taurovenator
Temporal range: Late Cretaceous, (Cenomanian), ~95–93.9  Ma
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Taurovenator violantei.png
Reconstruction of the head of Taurovenator violantei
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Theropoda
Family: Carcharodontosauridae
Tribe: Giganotosaurini
Genus: Taurovenator
Motta et al., 2016
Type species
Taurovenator violantei
Motta et al., 2016

Taurovenator ("bull hunter") is a large carcharodontosaurid theropod from the late Cretaceous Huincul Formation of Argentina that lived during the Cenomanian age of the Late Cretaceous. It is monotypic, containing only one species, T. violantei. [1]

Contents

Discovery and naming

The holotype of Taurovenator (MPCA-Pv 802), a right postorbital, was discovered in the lower [2] Huincul Formation on the Violante Farm, southeast of the Ezequiel Ramos-Mexía Lake, Río Negro Province, Argentina, by Matías Motta in 2005. Taurovenator was found in the vicinity of the megaraptoran Aoniraptor, several abelisauroids, and a possible unenlagiine paravian. [1]

In 2024, a new specimen of Taurovenator (MPCA-Pv 803) was described, preserving a partial skull, a partial cervical series, several ribs, two partial forelimbs, a femur, a partial pes, and a caudal vertebra. [2] The specimen was initially described in 2016 alongside the holotype, though it was originally regarded as indeterminate. [1] Despite not overlapping in material with the holotype, this specimen was referred to Taurovenator because it was recovered from the same locality as the holotype (the specimen was found 800 metres away from the holotype's dig site) and because it and the holotype preserve features of the Giganotosaurini. [2]

The generic name Taurovenator comes from the Latin taurus ("bull"), and venator ("hunter"). The specific name honors Enzo Violante, the owner of the Violante farm where the animal was discovered. [1]

Description

Taurovenator life reconstruction, compared to a person. Restauracion en vida de Taurovenator violantei.png
Taurovenator life reconstruction, compared to a person.

Taurovenator is a very large carcharodontosaurid. It had an estimated body mass of 5,728 kg (12,628 lb), based on a formula that utilizes the circumference of the femur to predict body mass. For reference, this is smaller than Giganotosaurus (6,349 kg), but larger than Meraxes and Mapusaurus (4,263 kg and 4,343 kg, respectively). [2] [3] The skull, though incomplete, is estimated to be 135 cm in length. [2]

The holotype showed that part of the postorbital bone was strongly rugose and projected out like a horn, markedly different from the orbital bosses of other carcharodontosaurids. Both Motta et al., 2016 and Rolando et al., 2024 consider this a unique trait, [1] [2] but its sister taxon Meraxes too has a postorbital that was described as laterally projecting out like a horn. [4]

Distinctively, Taurovenator's neck vertebrae bore prominent neural spines with flange-like dorsal tips. As a result, the neural spines of cervical vertebrae C3-C6 are "imbricated", ie interlocking with each other. The authors describing this morphology termed this unusual structure a "cervical complex", and likened them to overlapping roof tiles. A similar, though less extreme condition is also known in the C3-C5 of the more basal carcharodontosaurid Acrocanthosaurus . [2] [5] Available information of Giganotosaurus and Mapusaurus further suggests that this "cervical complex" is a unique synapomorphy of the group. The presence of the cervical complex would have likely restricted the range of movement of the cervical vertebrae. On the other hand, the skull of Taurovenator and other carcharodontosaurids had a ball-shaped occipital condyle similar to that seen in the skulls of ceratopsian dinosaurs. This could have allowed a large range of rotational movement between the skull and the first cervical vertebra. Furthermore, the cervical complex of Taurovenator could have similar functional implications to those of the syncervical vertebrae (ie fused C1-C3 vertebrae) of ceratopsians, strengthening the anterior region of the neck, and increasing the surface area for epaxial cervico-cranial muscles. [2]

Only remains of two dorsal vertebrae are known. One is composed of a centrum, but the other is composed of a very tall, 52 cm high neural arch. [2]

Taurovenator had proportionately the smallest arms of all known allosauroids. The nearly completely preserved arms were reduced to a greater degree than even in other carcharodontosaurids, being proportionately smaller than that of taxa such as Meraxes , particularly where the forearm is concerned. Despite such limb reduction, the forearms were robust, and the digits had a great degree of flexibility. Nonetheless like other giganotosaurines, the forelimbs were likely incapable of a wide range of movement. [2]

Taurovenator also shares with Meraxes an enlarged ungual claw on the second toe, approximately 20% longer than the equivalent phalanx of the third toe and more laterally compressed. [2]

Classification

Motta et al. (2016) suggested that Taurovenator occupied a derived position within Carcharodontosauridae, comparing it to Giganotosaurus, Carcharodontosaurus and Mapusaurus in particular. [1] Coria et al. (2019) suggested that Taurovenator is synonymous with Mapusaurus, considering both of its original autapomorphies as shared with Mapusaurus and also pointing out that both taxa shared a curved lateral margin of the palpebral. [6] Additionally, the authors considered that there was a high likelihood of them being coeval, [6] however, Taurovenator is actually from the lower unit of the Huincul Formation, while Mapusaurus is from the upper unit of the formation. [2] Rolando et al. (2024) reaffirmed Taurovenator's validity, considering the autapomorphies preserved on the holotype as more strongly developed in Taurovenator than any other carcharodontosaurid, while also considering the supposedly diagnostic curved margin of the palpebral as a more widely distributed feature in Carcharodontosauridae. [2]

In order to test the systematics of Taurovenator with the information supplemented by the new specimen, the study used the phylogenetic dataset used in the description of Meraxes, with some additional data. The results of their phylogenetic analysis are shown in a cladogram below: [2] [4]

Carcharodontosauridae

Paleoenvironment

Several dinosaurs from the Huincul Formation (Taurovenator not figured) Huincul Formation Dinosauria Scale.svg
Several dinosaurs from the Huincul Formation (Taurovenator not figured)

The fossil remains of Taurovenator were recovered from the Huincul Formation, which is known for a large assemblage of dinosaurian taxa. Two other giant carcharodontosaurids were discovered from the formation as well, Mapusaurus and Meraxes, though all being found in different layers it is unlikely they are coeval. [2] Other theropods include the paravian Overoraptor , the elaphrosaurine Huinculsaurus , the abelisaurs Skorpiovenator , Tralkasaurus , and Ilokelesia , and the megaraptoran Aoniraptor . [7] [8] Sauropods are the dominant herbivores of the area and are represented by the rebbachisaurid sauropods Cathartesaura and Limaysaurus along with the titanosaurs Argentinosaurus , Choconsaurus , and Chucarosaurus . [9] [10] [11] Ornithiscians are rarer fossil-wise, but are represented by indeterminate iguanodonts and the elasmarian Chakisaurus . [12]

See also

Related Research Articles

<span class="mw-page-title-main">Carcharodontosauridae</span> Extinct family of dinosaurs

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).

<i>Rugops</i> Genus of dinosaur

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 (14–17 ft) and weight of 410 kilograms (900 lb). 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.

<i>Mapusaurus</i> Carcharodontosaurid dinosaur genus from the Late Cretaceous

Mapusaurus was a giant carcharodontosaurid carnosaurian dinosaur from Argentina during the Turonian age of the Late Cretaceous.

<i>Rocasaurus</i> Genus of titanosaurian sauropod from the Late Cretaceous period

Rocasaurus is a genus of titanosaurian sauropod that lived in South America. Rocasaurus was discovered in Argentina in 2000, within the Allen Formation which is dated to be middle Campanian to early Maastrichtian in age. This genus grew up to 8 metres (26 ft) long, making it one of the smaller sauropods. It seems to be closely related to saltasaurid dinosaurs, like Saltasaurus and Neuquensaurus.

The Huincul Formation is a geologic formation of Late Cretaceous age of the Neuquén Basin that outcrops in the Mendoza, Río Negro and Neuquén Provinces of northern Patagonia, Argentina. It is the second formation in the Río Limay Subgroup, the oldest subgroup within the Neuquén Group. Formerly that subgroup was treated as a formation, and the Huincul Formation was known as the Huincul Member.

<span class="mw-page-title-main">Allen Formation</span> Geological formation in Argentina

The Allen Formation is a geological formation in Argentina whose strata date back to the Late Cretaceous (middle Campanian to early Maastrichtian. Dinosaur remains are among the fossils that have been recovered from the formation. Indeterminate chelid remains and other vertebrates have also been discovered in this formation.

<span class="mw-page-title-main">Chorrillo Formation</span> Geologic formation in southern Patagonia, Argentina

The Chorrillo Formation, also named as Chorillo Formation, is a Maastrichtian geologic formation in southern Patagonia, Argentina. The formation is more than 50 metres (160 ft) thick and underlies the Calafate Formation and rests on top of the La Irene Formation.

<i>Bonapartenykus</i> A large alvarezsauroid dinosaur

Bonapartenykus is a monospecific genus of alvarezsauroid dinosaur from Argentina that lived during the Late Cretaceous (Campanian-Maastrichtian) in what is now the upper Allen Formation of the Río Negro Province. The type and only species, Bonapartenykus ultimus, is known from a nearly articulated but partial skeleton that was found in close association to two incomplete eggs and several clusters of eggshells belonging to the oogenus Arriagadoolithus. Bonapartenykus was named in 2012 by Federico L. Agnolin, Jaime E. Powell, Fernando E. Novas and Martin Kundrát. Bonapartenykus has an estimated length of 2.5 m (8.2 ft) and weight of 72 kg (159 lb), making it the largest member of the clade Alvarezsauroidea.

Aoniraptor is a genus of possibly megaraptoran or bahariasaurid theropod dinosaur from the Late Cretaceous of Argentina.

<i>Lajasvenator</i> Genus of carcharodontosaurid (fossil)

Lajasvenator is a genus of carcharodontosaurid dinosaur from the Mulichinco Formation from Neuquén Province in Argentina. The type and only species is Lajasvenator ascheriae. It was probably one of the smallest known allosauroids, being approximately only half the length of Concavenator, about 2.9 m (9.5 ft).

Tralkasaurus is a genus of abelisaurid dinosaur from the Huincul Formation from Río Negro Province in Argentina. The type and only species is Tralkasaurus cuyi, named in 2020 by Mauricio Cerroni and colleagues based on an incomplete skeleton. A medium-sized abelisaurid, Tralkasaurus exhibits a conflicting blend of characteristics found among the early-diverging abelisauroids with others that characterize the highly specialized clade Brachyrostra, and thus its position within the clade is poorly-resolved.

<i>Overoraptor</i> Extinct genus of theropod dinosaurs

Overoraptor is an extinct genus of paravian theropod of uncertain affinities from the Late Cretaceous Huincul Formation of Argentinian Patagonia. The genus contains a single species, O. chimentoi, known from several bones of the hands, feet, and hips alongside some vertebrae.

<i>Niebla antiqua</i> Extinct species of dinosaur

Niebla is a genus of abelisaurid theropod dinosaur from the Late Cretaceous Period (Campanian-Maastrichtian) of Río Negro province, Argentina. The genus contains a single species, Niebla antiqua, and is known from a partial, non-articulated skeleton. The holotype, found in the Allen Formation, represents an adult individual about nine years old in minimum age.

<i>Maip</i> Genus of megaraptoran dinosaurs

Maip is a genus of large megaraptorid theropod dinosaur from the Late Cretaceous (Maastrichtian) Chorrillo Formation of Santa Cruz, Argentina. The genus contains a single species, M. macrothorax, known from an incomplete, disarticulated skeleton. Maip may represent the largest megaraptorid known from South America, and possibly the world.

<i>Meraxes</i> Genus of carcharodontosaurid dinosaurs

Meraxes is a genus of large carcharodontosaurid theropod dinosaur from the Late Cretaceous Huincul Formation of Patagonia, Argentina. The genus contains a single species, Meraxes gigas.

<i>Patagopelta</i> Genus of nodosaurid dinosaurs

Patagopelta is an extinct genus of ankylosaurian dinosaur from the Late Cretaceous Allen Formation of Argentina. The genus contains a single species, P. cristata, known from a partial skeleton. While originally described as a nodosaurine, later discoveries provided support for parankylosaurian affinities for the taxon. Patagopelta is a very small ankylosaur, comparable in size to the dwarf nodosaurid Struthiosaurus, about 2 m (6.6 ft) long.

<i>Yatenavis</i> Extinct genus of birds

Yatenavis is an extinct genus of enantiornithine bird from the Late Cretaceous Chorrillo Formation of Santa Cruz Province, Argentina. The genus contains a single species, Y. ieujensis, known from a partial humerus.

<i>Chucarosaurus</i> Genus of titanosaurian dinosaurs

Chucarosaurus is an extinct genus of titanosaurian dinosaur from the Late Cretaceous Huincul Formation of Argentina. The genus contains a single species, C. diripienda, known from various limb and pelvic bones.

Sidersaura is an extinct genus of rebbachisaurid sauropod dinosaur from the Late Cretaceous Huincul Formation of Argentina. The genus contains a single species, S. marae, known from the remains of four individuals. Sidersaura represents one of the largest known rebbachisaurids.

<i>Chakisaurus</i> Extinct genus of ornithopod dinosaurs

Chakisaurus is an extinct genus of elasmarian ornithopod dinosaur from the Late Cretaceous Huincul Formation of Argentina. The genus contains a single species, C. nekul, known from multiple partial skeletons belonging to individuals of different ages. Chakisaurus represents the first ornithischian species to be named from the Huincul Formation.

References

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