Alamosaurus: Geology students recently discovered a rare, nearly complete fossil of Alamosaurus at Big Bend National Park, United States.

• About: Alamosaurus is one of the largest dinosaurs ever known.

o Lived during the Late Cretaceous period (100.5 to 66 million years ago).

o Herbivorous sauropod with armoured spikes on its back for protection against predators.

o Belonged to sauropods, the largest land animals to ever evolve.

o Only known sauropod in North America from the Upper Cretaceous.

o Largest terrestrial animal in North America during the Upper Cretaceous.

o Rivalled in size with South America's Argentinosaurus (lived 97–92 million years ago).

o Had a long neck, tail, and pillar-like limbs typical of sauropods.

o Went extinct in the Cretaceous–Paleogene extinction event; among the last non-avian dinosaurs.