A plesiosaur can be cretaceous.Logical formLearned from2 sentences. A continent may pull in a cretaceous period.Logical formLearned from2 sentences. Mammals can be in a cretaceous period.Logical formLearned from2 sentences. Some birds can be from a cretaceous period.Logical formLearned from2 sentences. Some (dinosaur embryos) can be from a cretaceous period.Logical formLearned from2 sentences. A day can be in a cretaceous period.Logical formLearned from2 sentences. Sediments may mark a boundary of cretaceous periods.Logical formLearned from2 sentences. A herbivore can be cretaceous.Logical formLearned from2 sentences. An old man can be cretaceous.Logical formLearned from2 sentences. (Period fossils) can be cretaceous.Logical formLearned from2 sentences. A breakup may occur in a cretaceous period.Logical formLearned from2 sentences. An insect may be knowned from a cretaceous period.Logical formLearned from2 sentences. A creekbed can be cretaceous.Logical formLearned from2 sentences. A belt can be cretaceous.Logical formLearned from2 sentences. Clay-shales can be cretaceous.Logical formLearned from2 sentences.