Describer

Sereno and Brusatte 2008

Time

Cretaceous Early Aptian Albian

Classification

Saurischia Theropoda Tetanurae Carnosauria Carcharodontosauridae

Diet

Carnivore

Fossilsite

“Gadoufaoua” on the western edge of the Ténéré Desert; type locality has coordinates N 1688’ and E 988 Echkar Formation, Niger

Info

Genus - Typespecies - Skull

Represented by several cranial bones and isolated teeth. Phylogenetic analysis places it as a basal carcharodontosaurid, similar to Acrocanthosaurus and less derived than Carcharodontosaurus and Giganotosaurus. The discovery of these taxa suggests that large body size and many of the derived cranial features of abelisaurids and carcharodontosaurids had already evolved by the mid Cretaceous. The presence of a close relative of the North American genus Acrocanthosaurus on Africa suggests that carcharodontosaurids had already achieved a trans−Tethyan distribution by the mid Cretaceous.

Etymology

From Greek eos, dawn; karcharias, shark (Greek); in reference its basal position in the “shark−toothed” theropod clade Carcharodontosauridae. From Greek dinops, fierce−eyed; in reference to the massive ornamented brow above the orbit.

Holotype

MNN GAD2, a complete left postorbital.

Referred material

MNN GAD3, complete left postorbital; MNN GAD4, partial right postorbital; MNN GAD5, partial right postorbital; MNN GAD6, partial right postorbital; MNN GAD7, nearly complete left maxilla; MNN GAD8, right maxillary fragment; MNN GAD9, left maxillary fragment; MNN GAD10, left frontal and prefrontal; MNN GAD11, frontoparietal; MNN GAD12, three teeth; MNN GAD13, tooth fragment; MNN GAD14, complete crown.

Diagnosis

Large−bodied carcharodontosaurid with enlarged subtriangular laterally exposed promaxillary fenestra larger in size than the maxillary fenestra, a circular accessory pneumatic fenestra on the posterodorsal ramus of the maxilla, dorsoventral expansion of the antorbital fossa ventral to the promaxillary and maxillary fenestrae, postorbital brow accentuated by a finely textured ovoid swelling, or boss, positioned above the posterodorsal corner of the orbit, postorbital medial processwith a plate−shaped projection fitted to an articular slot on the frontal, postorbital articulation for the jugal that includes a narrow laterally−facing facet, an enlarged prefrontal lacking the ventral process with subquadrate exposure on the dorsal skull roof and within the orbit (limiting the anterior ramus of the frontal to the roof over the olfactory bulbs), and a low protuberance on the frontoparietal suture.

Eocarcharia dinops also differs from other carcharodontosaurids such as Acrocanthosaurus, Giganotosaurus, and Carcharodontosaurus by the low proportions of the suborbital flange on the postorbital and from Mapusaurus, Giganotosaurus, and Carcharodontosaurus by the absence of extensive external neurovascular grooves on the maxilla and blade-shaped crowns with prominently developed, marginal, arcuate enamel wrinkles in upper and lower tooth rows. Unlike these advanced carcharodontosaurids, Eocarcharia retains the prefrontal as a separate element and has only a rudimentary lacrimal−postorbital suture. Finally, Eocarcharia has a relatively small planar sutural surface on the postorbital for the squamosal, rather than the more complex spiral articulation observed in Carcharodontosaurus , Mapusaurus, and Giganotosaurus. (Sereno and Brusatte 2008)

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