Overoraptor

Overoraptor (meaning "piebald thief") is a genus of paravian theropod dinosaurs, which was closely related to "Rahonavis", from the Late Cretaceous (Cenomanian) Huincul Formation of Gondwana, present-day Argentina. It includes one species, Overoraptor chimentoi.
Etymology.
The generic name "Overoraptor" is derived from the Spanish "overo", meaning piebald, in reference to the color of the fossil bones. The specific name, "O. chimentoi", refers to Roberto Nicolás Chimento, who discovered the remains.
Description and classification.
Although the holotype is very fragmentary, it exhibits an unusual combination of features that reveal a novel phylogenetic position. The forelimb exhibits a bird-like morphology that includes, among other things, a robust ulna, while the hindlimb appears to have been adapted for a cursorial lifestyle. A "sickle-claw" similar to that of dromaeosaurs is also present. Both a flight-adapted forelimb and a cursorial hindlimb are present in "Rahonavis", also from Gondwana, and the describers suggest the two are closely related taxa. 
The describers ran a phylogenetic analysis and recovered a novel position for "Overoraptor" and "Rahonavis", being outside of Unenlagiidae and Avialae, to which the latter has sometimes been assigned to. Their cladogram is shown below, based on a previous study by Agnolin & Novas (2013):
Paleoenvironment.
"Overoraptor" was found in the Huincul Formation, a geological unit that has been extensively studied in recent years. "Overoraptor" lived alongside theropods such as the noasaurid "Huinculsaurus", abelisaurids like "Skorpiovenator", "Ilokelesia" and "Tralkasaurus", carcharodontosaurids like "Mapusaurus" and indeterminate theropods like "Gualicho" and "Aoniraptor". Sauropods were represented by the rebbachisaurids "Cathartesaura" and "Limaysaurus", the titanosaurs "Argentinosaurus" and "Choconsaurus", and some unnamed species. Ornithischians were represented by unnamed iguanodonts.