A speculative portrait of the ceratosaurid Genyodectes serus for the challenge. Partial upper and lower jaws of Genyodectes, complete with teeth, were found in Lower Cretaceous rocks of Argentina's Cerro Barcino Formation. The dinosaur was described by sir A. Woodward in 1901 and remained the most complete Argentine theropod until the 1970s. Due to its fragmentary state, it was assigned to various theropod groups, including megalosaurids, tyrannosaurids, and abelisaurids. It was even considered a nomen dubium (a dubious name). Additional preparation allowed for a better understanding of the remains, and in 2004, O. Rauhut classified the reptile as a ceratosaurid. Like Ceratosaurus, Genyodectes had long maxillary teeth, but differed in having four premaxillary teeth instead of three. Besides Genyodectes, sauropods, including the gigantic Patagotitan, and the massive carcharodontosaur Tyrannotitan are known from the Cerro Barcino Formation.

(genyodectes serus sketch)

Conjectural portrait of Genyodectes, the poorly-understood meat-eating dinosaur, known only from the tip of its jaws (see inset image). It lived around 125 to 113 million years ago, in an ecosystem of sand dunes and swamps in what is now South America.

Source: http://teratophoneus.deviantart.com/art/Genyodectes-serus-368113900

Name: Genyodectes serus 

Name Meaning: Late jaw bite

First Described: 1901 

Described By: Woodward 

Classification: Dinosauria, Saurischia, Eusaurischia, Theropoda, Neotheropoda, Averostra, Ceratosauria, Neoceratosauria, Ceratosauridae 

Genyodectes was an early Cretaceous ceratosaurian from the Aptian age, around 112 million years ago. It was found in the Cañadón Grande, Departamento Paso de Indios in the Chubut Province of Argentina. It's not known from many remains - mainly just the front of the jaw and upper mandible and many teeth. However, given the arrangement of the teeth, it seems to resemble Ceratosaurus more than other theropods. Given that, it was only recently that it was classified as such, and has been named everything from a megalosaurid to a tyrannosaurid. However, recent removal from its display matrix has allowed it to be classified as a ceratosaur. It was also one of the earliest dinosaurs found in South America. 

Sources: 

http://www.dinochecker.com/dinosaurs/GENYODECTES

http://en.wikipedia.org/wiki/Genyodectes