Out of all the dinosaur fossil bearing formations in South America the Cañadon Asfalto Formation is probably the most obscure, yet it provides several intresting fossils that give us an insight about often overlooked Jurassic fauna of South America.
The Callovian-Oxfordian age (166-156 ma) as whole is often overlooked in general, yet it has a suprisingly large amount of dinosaur discoveries and even full fledged ecosystem from that time, most notably in Asia.
The Callovian fauna of Argentina isn't too rich as far as we currently know, with a notable absence of numerous types of dinosaurs like stegosaurs and ornithopods and only one, very fragmentary pterosaur taxon has been found in this formation, yet at least 3 types of large sauropods have been unearthed here, including a cetiosaur and camarasaur, hower it's most intresting finds are a trio of theropods, 2 of which are a pair of closely related megalosaurs, both around 4,5 m long, the long snouted Condorraptor and the more box faced Piatnitzkysaurus. These 2 are the main representetives of the piatnitzkysaurs, a basal subgroup of megalosaurs even more distant from the "true megalosauru" liniage then even the spinosaurs.
The other theropod found here was Eoabelisaurus, who as it's name implies is one of the oldest known abelisaurs and a suprising bit of evidence of how far back this highly sucesfull group of ceratosaurs went, as they are usually assosiated with the Cretaceous. And intrestingly, with a lengh of nearly 6 m it was the largest carnivore in the ecosystem that we know of, dwarfing the local tetanurans, which makes it an intresting subversion of the usual predator hierarchy of the late Jurassic.
Another intresting find was Argentoconodon, a volaticother mammal that was a sort of bat-fly squirrel hybrid.