Taurovenator, from Latin taurus, meaning "bull", and venator, meaning "hunter", is an extinct genus of large, probable carcharodontosaurid theropod dinosaurs that lived in what is now Argentina during the Cenomanian age of the Late Cretaceous, around 95 to 93.9 million years ago. Initially only known from a single Postorbital bone skull bone described from the Huincul Formation, Taurovenator violantei was named in 2016 by Argentine paleontologist Matias Motta and colleagues. Debate came about over the validity of the species, with some paleontologists arguing that Taurovenator was synonymous with the earlier-named carcharodontosaurid Mapusaurus. However, the 2024 description of a well-preserved partial skull and skeleton referrable to Taurovenator aided in distinguishing the two taxa.
Discovery and naming
Initial discovery and description
In 2005, a right
Postorbital bone of a
theropod dinosaur was unearthed by Argentine paleontologist
Matias Motta from a section of
sandstone Stratum deriving from the lower member of the Huincul Formation, dating to the
Cenomanian stage of the
Late Cretaceous (95-93.9 million years old).
The strata located on the Violante Farm, a farm located in Rio Negro Province, Argentina. This fossil was found in the vicinity of the
Aoniraptor, several
Abelisauroidea, and a possible
Unenlagiinae Paraves.
The fossils recovered were then transported to the Museo Provincial "Carlos Ameghino", with the isolated postorbital deposited under catalogue number MPCA-Pv 803.
This postorbital remained undescribed until in 2016, when Matias Motta and colleagues described the postorbital as the
holotype (name-bearing specimen) of a new
genus and
species of carcharodontosaurid dinosaur,
Taurovenator violantei.
Taurovenator was then the second carcharodontosaurid described from the Huincul Formation, with
Mapusaurus named in 2006 based on several incomplete skeletons.
[Coria, R. A., & Currie, P. J. (2006). A new carcharodontosaurid (Dinosauria, Theropoda) from the Upper Cretaceous of Argentina. Geodiversitas, 28(1), 71-118.] The generic name
Taurovenator means "bull hunter", derived from the
Latin roots
taurus "bull" and
venor "hunter" whereas the specific name is in honor of Violante Farm where the postorbital was unearthed.
Validity debate and additional specimen
Taurovenator went largely unnoticed due to its fragmentary nature,
with Coria et al. (2019) suggesting 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.
Additionally, the authors considered that there was a high likelihood of them being ,
however,
Taurovenator is actually from the lower unit of the Huincul Formation, while
Mapusaurus is from the upper unit of the formation.
Researcher
Mickey Mortimer also believed that
Taurovenator was synonymous with
Mapusaurus due to the lack of sufficient material and diagnostic traits for the genus.
In 2022, another carcharodontosaurid from the Huincul Formation,
Meraxes, was named on the basis of a well-preserved skull and partial skeleton from the same strata as
Taurovenator. In their description of
Meraxes, the authors stated that
Taurovenator lacks sufficient diagnostic characters and may be coeval with
Meraxes.
Notably in the same site on Violante Farm as the Taurovenator holotype, an associated skeleton (MPCA-Pv 803) including a partial skull and posterior (back portion) mandible, incomplete cervical (neck vertebrae) series, fragments of dorsal (back) vertebrae, several Rib cage, two partial Forelimb, a femur (thighbone), a partial pes (foot), gastralia, and a was unearthed along with the Taurovenator holotype in 2005 but were regarded as belonging to an indeterminate carcharodontosaurid in the 2016 description of Taurovenator. Additionally, the material of MPCA-Pv 803 had not been completely collected, prepared, or made available for study, delaying its description.
Description
Taurovenator is a very large carcharodontosaurid. It had an estimated body mass of , , based on a formula that utilizes the circumference of the femur to predict body mass. For reference, this is smaller than
Giganotosaurus , but larger than
Meraxes and
Mapusaurus, and , respectively).
This puts
Taurovenator among the largest theropod dinosaurs known and therefore one of the biggest terrestrial carnivores known to science, though still smaller than genera like
Tyrannosaurus and
Spinosaurus.
Skull
The skull of
Taurovenator is known from the holotype postorbital in addition to the cranial and mandibular elements of MPCA-Pv 803 which include: both (cheekbones), left (skull bone articulating with the lower jaw), left (main palate bone), right (smaller palate bone), both and (back of lower jaw bones), (rearmost lower jaw bone), left (lower jaw bone articulating with the skull), right (throat bone), and three isolated
Tooth. The maximum length of the skull of MPCA-Pv 803 was estimated to be around based on the more complete skulls of relatives like
Meraxes. The is 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,
but its sister taxon
Meraxes too has a postorbital that was described as laterally projecting out like a horn.
The 2024 description of MPCA-Pv 803 however argued that this horn-like projection is distinct from that of
Meraxes, with the projection measuring in height and in diameter. In addition, there is a deep (depression in bone) and excavation on the ventral surface of the postorbital. Though the excavations are observable in the postorbitals of
Mapusaurus, Meraxes, and other carcharodontosaurids, they all do not preserve the unique fossa found on the
Taurovenator holotype.
The jugal is long and sub-triangular in shape with a slightly posteromedially (backwards) pointed postorbital . Its lateral (exposed side) surface is rugose with a thick shelf, a condition similarly observed in South American carcharodontosaurids like Tyrannotitan and Meraxes but absent from the jugals of other Carnosauria. The anterior (front) of the jugal is compressed and bears an ovular (pits in bone for air sac systems) on its articulating (contacting) surface with the . The quadrate of MPCA-PV 803 is distinctly stout, triangular in lateral view, bearing a large, anteriorly projected pterygoid flange as in related genera. The pterygoid fossa is wide, subdivided by a crest, and lacks pneumaticity as in contemporary carcharodontosaurids of its time. In contrast the palatine of Taurovenator is tetraradiate with an anteriorly expanded vomeropterygoid (expansion), a short and sub-triangular pterygoid process, a narrow jugal process, and an elongated maxillary process. The ectopterygoid is C-shaped from dorsoventral (top and bottom) views with a pneumatic on its medial surface, a trait in other tetanurans. A distinguishing feature of Taurovenator's pterygoid is the thin, long jugal process which is longer than those of Meraxes and Giganotosaurus. As for the mandible, only the posterior portion is known from Taurovenator. It preserves a robust and dorsoventrally (top-down) high morphology, akin to the mandibles of Acrocanthosaurus, Tyrannosaurus, and other Tyrannosauroidea. Two teeth are preserved from Taurovenator, both of which are large, around in length. The margins of these teeth are convex and straight, with chisel-like denticles which number around 8.5 per at the mid-crown and 11 per at the base. Their blood grooves are well developed and their Tooth enamel wrinkles are notably deep,[Farlow, J. O., Brinkman, D. L., Abler, W. L., & Currie, P. J. (1991). Size, shape, and serration density of theropod dinosaur lateral teeth. Modern Geology, 16(1-2), 161-198.]
Postcrania
Distinctively
, Taurovenator's neck vertebrae bore prominent
Vertebra 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.
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
Ceratopsia 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.
Only remains of two dorsal vertebrae are known. One is composed of a centrum, but the other is composed of a very tall, high neural arch. This neural spine preserves strong laminae that form an "H"-shaped cross-section and a saddle shape at the top, traits found in the high-spined Acrocanthosaurus. As for the appendicular skeleton, the forelimbs are nearly completely preserved, missing only the carpals and ungual phalanges. Taurovenator had proportionately some of the smallest arms of all known allosauroids, being 65-68% of the length of the femur. 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.
Classification
Motta et al. (2016) suggested that
Taurovenator occupied a derived position within Carcharodontosauridae, comparing it to
Giganotosaurus,
Carcharodontosaurus and
Mapusaurus in particular.
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.
[ Additionally, the authors considered that there was a high likelihood of them being ,]
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:
In 2025, Cau and Paterna recovered Taurovenator as an allosauroid outside Carcharodontosauridae.
Palaeoenvironment
Taurovenator was discovered in the Argentine Province of Neuquén. It was found in the Huincul Formation, a rock formation bordering the Río Limay Subgroup, the latter of which is a subdivision of the Neuquén Group. This unit is located in the Neuquén Basin in Patagonia. The Huincul Formation is composed of yellowish and greenish of fine-to-medium grain, some of which are .
Fossilised pollen indicates a wide variety of plants were present in the Huincul Formation. A study of the El Zampal section of the formation found , , , Selaginellales, possible Noeggerathiales, (including and ), and (flowering plants), in addition to several pollen grains of unknown affinities.
In addition to Taurovenator, the theropods of the Huincul Formation are represented by the other giant carcharodontosaurids Meraxes and Mapusaurus, including Skorpiovenator,
See also
