Wikipedia article of the day is Argentinosaurus. Check it out:
Article-Link Summary: Argentinosaurus is a genus of giant sauropod dinosaur that lived during the Late Cretaceous in what is now Argentina. It was one of the largest land animals of all time, and possibly the largest, with length estimates ranging from 30 to 39.7 metres (98 to 130 ft) and weight estimates from 50 to 100 tonnes (55 to 110 short tons). It was a member of Titanosauria, the dominant group of sauropods during the Cretaceous. The first Argentinosaurus bone was discovered in 1987 by a farmer near the city of Plaza Huincul in the Huincul Formation, which is rich in dinosaur fossils. A scientific excavation of the site led by the Argentine palaeontologist José Bonaparte was conducted in 1989, yielding several back vertebrae and parts of a sacrum—fused vertebrae between the back and tail vertebrae. Additional specimens include a complete femur (thigh bone) and the shaft of another. The fragmentary nature of the remains makes their interpretation difficult.