Acrocanthosaurus, claw of hand Argentinosaurus Complete left lower jaw from

Complete left lower jaw from the Late Cretaceous of Alberta

Aspidella terranovica Billings

It was heavy and supported by the last seven tail vertebrae

These limestone beds are the result of a series of islands and shallow lagoons

analysis by Erik Seiffert in 2006 concluded that the age of the Jebel Qatrani Formation should be revised

Acrocanthosaurus, claw of hand Argentinosaurus Complete left lower jaw fromAcrocanthosaurus (meaning "high spine lizard" because of the spikes growing out of its spine) was a fierce predator that was roughly 30 40 feet (9 12 m) long and weighed about 5,000 pounds (2300 kg). It had a big head, with a 4. 5 foot (1. 4 m) long skull and 68 thin, sharp, serrated teeth. It had 17 inch (43 cm) spikes extending from its vertebrae, along the neck and tail that may have formed a thick, fleshy sail on its back. It had powerful arms,