This paper looks to confirm the semi-aquatic lifestyle of Spinosaurids using oxygen isototopes in their bones.
Direct evidence concerning spinosaurid diet was inconclusive since it appears that they also fed on dinosaurs and pterosaurs. Because of the shape of their jaw/teeth and fish remains in their stomach, the hypothesis of spinosaurs as “crocodile mimics” has been widely accepted. However, their postcranial anatomy differs relatively little from that of the usual large theropods, and is not particularly suggestive of aquatic habits.
So the paper concluded that stable oxygen isotopes unambiguously show for the first time that some dinosaurs, i.e., the spinosaurid theropods, used freshwater environments more as a living habitat than just as temporary hunting grounds.
W020120622356922971023.pdf