What as allosaurus habitat?

Allosaurus fossils have been found in the Morrison Formation of the western USA, the Tendaguru Formation of Tanzania, and the Lourinhã Formation of Portugal and date to between 155 and 150 million years ago. The two former areas, if not all three, were semi-arid, subtropical to tropical plains with distinct wet and dry seasons. Along rivers, there would have been forests of conifers, cycads, ginkgoes, ferns, and horsetails. Farther from the rivers there were open expanses, but rather than being covered in grass, which didn't exist yet, they were covered in ferns, and there were scattered trees. Allosaurus probably preferred the more open areas for hunting.