Compsognathus, commonly known as "The poodle of dinosaurs", was thought for decades to be the smallest dinosaur. The first specimen collected was around 1 m (3 ft) in length. However, more recent discoveries, such as Caenagnathasia, Microraptor and Parvicursor, were even smaller.
When the partial femur of Megalosaurus was unearthed in England in 1676, Robert Plot, the curator of an English museum, mistakenly identified it as belonging to a human giant. It took another 150 years for William Buckland to give this genus its distinctive name, and nearly 20 years after that for Megalosaurus to be conclusively identified as a dinosaur by the famous paleontologist Richard Owen.
Most of the dinosaur fossils unearthed in the late 18th and early 19th century belonged to relatively small ornithopods or slightly bigger theropods. The discovery of Diplodocus in western North America's Morrison Formation in 1877 ushered in the age of the giant sauropods which have since captured the public imagination.