The discovery of the Bernissart Iguanodons, of Hadrosaurus and of Compsognathus was reinforcing the view that dinosaurs were indeed bipedal.   However, by 1877 North American explorers were finding evidence of huge quadrupedal dinosaurs, far larger than anything previously known.   They were labelled as sauropods.

In 1877 Othniel Marsh found the bones of a gigantic sauropod which he named Apatosaurus.

In 1879 a near complete skeleton was found in Lake Como. Wyoming, by Marsh, who named it Brontosaurus.   He went on to publish a full skeletal restoration of the creature in 1883.   Unfortunately he made 2 errors :

1.   The Brontosaurus was actually the same creature as the Apatosaurus that he had named 2 years earlier.   Nowadays it is referred to as an Apatosaurus.

2.   The skeleton discovered in 1879 was missing its head and so Marsh estimated its appearance, based on a Camarosaurus.   Marsh did not point this out at the time, and so later restorations continued to use the wrong 'head' on the creature, until the late 1970s.  Thus during the 1980s a large number of Camarosaurus heads were removed from Apatosaurus restorations around the world

Apatosaurus, with a Camarosaurus head. (A.Avinoff 1936).

The famous Carnegie mount of Apatosaurus louisae, mounted in 1913 with a Camarasaurus cast for a head.  The original specimen, found in 1909 by Earl Douglas, had no head, but a Camarasaurus-like skull was found nearby.