Spinosaurs (or spinosaurids) were the last major group of theropod dinosaurs to evolve during the Mesozoic Era.
Spinosaurs appeared during the late Jurassic with the earliest know species being Ostafrikasaurus.
They remained very uncommon during that period until the Early Cretaceous.
Unlike the other theropods, they already appeared to be at least semi-aquatic, with overly large talons on their front legs and with elongated, crocodile-like snouts. Baryonyx in particular was often depicted (initially) as a four-legged animal, but lately this theory is disputed.
The spinosaurs heyday was during the early Cretaceous, when they evolved several new species, such as Irritator, Suchomimus, and, especially Spinosaurus, which is currently considered to be the biggest theropod dinosaur ever. They kept their initial traits - large and robust forelegs, an elongated snout - but have also developed a large sail on their back, which reached its' peak in Spinosaurus. The use of that sail is currently disputed, and some believe that the sail was actually a fat-storing hump, similar to the modern Bison.
All spinosaurs were semi-aquatic animals and depended in part of hunting and eating fish to survive. When in the second half of Cretaceous the sea levels began to rise and Earth's climate began to change, they died out.
Spinosaurs are commonly depicted as heron-like waders, but oxygen isotopes from Spinosaurus indicate they where just as aquatic as crocodiles are today.
Portrayal in the seriesEdit
Spinosaurus and Suchomimus are dinosaurs featured in this app.