Ceratosaurus

Ceratosaurus ("horned lizard") was a Late Jurassic dinosaur know due to its horn in its nose. It was mainly portrayed before the 70s (Brute Force, The Animal World, Fantasia), until it lost popularity due to new discoveries, essentially being replaced by Carnotaurus.

Iberomesornis's Idea
The enviroment would be similar to other Morrison and Lourinha formations animals. Ceratosaurus itself should have a lake, as it was probably a good swimmer which prefered to hunt fish and crocodiles. Scanvenging would also form part of this animal's diet. Ceratosaurus juveniles would be in hunt with the rest of the pack, whic the adults would protect. Scratching posts should be avaible during mating seasons, for the theropods to "sharpen" their horns to be more noticeable.