 Since the 1930s , Barnum Brown described that an <unk> species of Kritosaurus had inhabited the late Maastrichtian Ojo Alamo Formation , the <unk> Formation in Texas and the El Picacho Formation , which was a flood plain type environment at the time of the Cretaceous . However , it should be noted that these fossils might be of an unknown species of hadrosaur or an undescribed specimen of Kritosaurus . This genus lived alongside numerous species of dinosaurs including the sauropod Alamosaurus , the ceratopsians <unk> , Ojoceratops , Torosaurus and a possible species of <unk> , hadrosaurs which included a possible species of Edmontosaurus annectens , Saurolophus and Gryposaurus and the armored nodosaur Glyptodontopelta . Theropods from this environment which included Tyrannosaurus , smaller theropods like a species of Troodon and Richardoestesia , the oviraptorid <unk> , indeterminate ornithomimids and dromaeosaurs . Non @-@ dinosaur species that had shared the same environment with Kritosaurus included the giant pterosaur Quetzalcoatlus , various species of fishes and rays , amphibians , lizards , turtles like Adocus , and multiple species of mammals like Alphadon and Mesodma . 
