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Eocarcharia () is an extinct genus of theropod dinosaurs found in what is now the western Ténéré Desert of Niger. It is known from several skull bones collected in 2000 by an expedition to the Early Cretaceous (Aptian–Albian ages) Elrhaz Formation (Gadoufaoua locality) led by American paleontologist Paul Sereno. The fossil material was then described in 2008 by Sereno and Steve Brusatte. The genus contains a Monotypic taxon, Eocarcharia dinops. While Sereno and Brusatte identified all of the remains as belonging to a new carcharodontosaurid, later studies suggested that the species is chimaeric, comprising bones of at least two unrelated taxa. Some of the Eocarcharia material, including the holotype (name-bearing) specimen, likely belongs to a baryonychine spinosaurid. This would render Eocarcharia a member of this group, closely related to the coeval Suchomimus. Meanwhile, the definitively carcharodontosaurid bones, a and teeth, belong to a distinct unnamed taxon.
Little is known about Eocarcharia due to its fragmentary and chimaeric nature. When considered a carcharodontosaurid, it was estimated to be long, making it smaller than derived carcharodontosaurids like Giganotosaurus, and Carcharodontosaurus. The (bone behind the orbit) is robust with a large brow, a distinct characteristic of Eocarcharia. It was possibly covered in keratin and used for Headbutt with other individuals of its species. Eocarcharia lived in an environment with rivers and vast alongside many other dinosaurs, pterosaurs, crocodylomorphs, and freshwater animals.
In 2008, Sereno and Steve Brusatte described all of these remains as belonging to a new genus and species of carcharodontosaurid dinosaur, named Eocarcharia dinops. They established one of the postorbitals, MNN-GAD2, as the holotype (name-bearing) specimen. The generic name, Eocarcharia, derives from the Ancient Greek words eos, meaning , and karcharias, meaning , referencing the early-diverging nature of Eocarcharia in relation to its 'shark-toothed' relatives. The specific name, dinops, is a Greek term meaning , referring to the unique postorbital ornamentation above the eye.
The margins of the postorbital make up segments of the orbit edges, the , and the . Several of the postorbitals known from Eocarcharia preserve the Joint for the , which are deep and long. These articular surfaces are very small and deep proportionally for a carcharodontosaurid, making this characteristic a diagnostic trait of Eocarcharia. In contrast, the point of contact between the postorbital and the frontal is rugose and bears a unique, plate-shaped process (projection of bone) that interlocks with a concavity on the frontal. Another diagnostic trait of Eocarcharia is that its postorbital bears a narrow facet which articulates laterally with the (cheekbone), whereas carcharodontosaurids like Carcharodontosaurus have broader facets. Midshafts of the ventral (bottom) ramus (a branch of bone) of the postorbital in spinosaurids and Megalosauridae are typically U-shaped in cross-section, whereas in Eocarcharia it is subtriangular in cross-section. An infraorbital process is also present on the postorbital ventral ramus of Eocarcharia, distinct from those of other carcharodontosaurids in that it is small, rugose, and distally-positioned (away from the body core).
The frontal is known from Eocarcharia, and is proportionally very broad at its mid-length, similar to that of Carcharodontosaurus. In dorsal view, the supratemporal (a depression along the temporal fenestra) is greatly exposed, another diagnostic characteristic. In ventral view, the anterior portion of the frontal is exposed, forming the roof of the Olfactory bulb section of the endocranium (the part of the skull that holds the brain). This portion of the frontal is narrow, in contrast to those of tetanurans, where it is typically broad. Notably, a prefrontal is also preserved. Independent prefrontals are absent in advanced carcharodontosaurids as they are typically co-ossified (fused) with the into a single element, whereas in earlier genera like Eocarcharia, Acrocanthosaurus, and Concavenator, they are unfused. In Eocarcharia, the prefrontal is relatively wide, about half the width of the frontal. The prefrontal bears an extended process that articulates with the deep, squared articular notch on the frontal. On the ventral (bottom) side of the frontal, theropods typically feature an extended process that travels along the posteromedial (back inner) portion of the bone. Eocarcharia lacks this process.
In the same 2008 paper, Sereno and Brusatte named Kryptops based on an abelisaurid maxilla and postcranial remains. They assigned the postcranial material to the same individual as the maxilla based on their close association and alleged basal abelisaurid features in the vertebrae and pelvis. In 2012, Matthew Carrano and colleagues considered Kryptops palaios to be a chimera (specimen composed of multiple species), stating that its postcranial remains, especially the pelvis and sacrum, may belong to a carcharodontosaurid, possibly Eocarcharia. Since these bones do not overlap with the Eocarcharia holotype, they could not be definitively referred to this taxon. The hypothesis that these postcranial bones do not belong to Kryptops was supported by later studies, which agreed that the remains belonged to a carcharodontosaurid or a metriacanthosaurid.
In their 2024 description of a new specimen of the giant carcharodontosaurid Taurovenator, Rolando and colleagues included Eocarcharia in their phylogenetic analysis, recovering it as an early-diverging member of the clade, branching after Neovenator. These results are displayed in the cladogram below:
The skull bones of Eocarcharia belong to multiple individuals and were found in different sites. As such, the taxonomic identity of these bones—and whether or not they can all be referred to the same taxon—has been debated. In their description of the carcharodontosaurid Tameryraptor, Kellermann, Cuesta & Rauhut (2025) scored the holotype postorbital (including a referred frontal with articular surfaces that match those of the postorbital) and referred maxilla as separate operational taxonomic units (OTUs) to test the likelihood that they belonged to the same taxon. In their analyses, both OTUs were consistently recovered in different positions, supporting their status as distinct taxa. The maxilla was reliably recovered as a carcharodontosauriform, either as a non-carcharodontosaurine carcharodontosaurid or as a metriacanthosaurid. On the other hand, the holotype was recovered in positions as a basal carcharodontosaur, or variably inside or outside of Carcharodontosauriformes. They interpreted these results as indicative of the referred maxilla skewing past analyses toward carcharodontosaur affinities for the taxon.
Cau and Paterna's phylogenetic results placed Eocarcharia as the sister taxon to Suchomimus. Both species differ in fourteen characters, precluding their taxonomic synonymization. This also provides further evidence for an observed trend of at least two spinosaurids coexisting in one ecosystem (e.g., Ceratosuchops and Riparovenator in the Wessex Formation). Since the maxilla OTU was recovered as distinct from the holotype + skull roof OTU, Cau and Paterna suggested that this bone—which demonstrates apparent allosauroid anatomy consistent with carcharodontosaurids—should be referred to a new taxon. Abbreviated results of their phylogenetic analysis are displayed in the cladogram below, with both Eocarchia OTUs indicated: the skull roof and holotype within the spinosaurid clade Ceratosuchopsini and the maxilla as a basal carcharodontosaurid. ⊞ buttons can be clicked to expand nodes.
Notably, spinosaurid similarities have been noted before Cau and Paterna's 2025 analysis; in 2022, Sereno and colleagues reported a newly-discovered skull roof specimen they assigned to Suchomimus. The similarity of this specimen to the postorbital and frontal of Eocarcharia was noted by Schade and colleagues the following year. In early 2025, Kellermann, Cuesta & Rauhut reinforced this comparison, claiming that the Suchomimus specimen may even belong to Eocarcharia. Cau and Paterna acknowledged these similarities, but noted characters more consistent with Suchomimus than Eocarcharia. They also commented on the possibility that some of the other specimens traditionally referred to Suchomimus may actually belong to Eocarcharia.
Eocarcharia lived alongside several other dinosaurs. These included other theropods, such as the spinosaurid and probable close relative Suchomimus, Kryptops (known from a chimaeric combination of abelisaurid and allosauroid material), and the putative noasaurid Afromimus. Several Megaherbivore, including the hadrosauriforms Ouranosaurus and Lurdusaurus, the dryosaurid Elrhazosaurus, and two sauropods, the rebbachisaurid Nigersaurus and an unnamed titanosaur, have been unearthed from Gadoufaoua. Together, these comprise one of the few associations of megaherbivores with a balance of sauropods and large ornithopods. Crocodylomorphs including Anatosuchus, Araripesuchus, Sarcosuchus, and Stolokrosuchus were also found in these rock layers. In addition, remains of an unnamed ornithocheirid pterosaur, turtles, bony fish, a hybodont (shark-like fish), and bivalves have been found. The aquatic fauna consists entirely of freshwater inhabitants.
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