Today, most of us would recognize a fossil bone for what it is, but in
the 1790’s things were different. Isolated legbones, vertebrae, and
teeth of huge reptiles had been dug out of certain sedimentary rocks of
Europe and North America but their scientific importance was little
understood.
These specimens were found by people in all walks of life and it was
natural that their curiosity was greatly aroused. The finders took the
specimens to someone nearby whom they considered more competent to tell
them something about these strange bones and teeth. In nearly all cases
these “experts” were doctors of medicine. They studied the fossil
specimens and reported on them at regular meetings of the learned
societies of which they were members. It was customary to put the
fossils in the collections of these societies where they could be
studied by other members. In North America most reports of these early
discoveries are found in the _Proceedings of the American Philosophical
Society_ in Philadelphia, Pa.
By 1842 accumulated knowledge of these large reptiles was sufficient to
show that they were distinct from any group then known. This was first
recognized by Sir Richard Owen of the British Museum. It was he who
named the group _Dinosauria_. The name is made up of two Greek words:
_deinos_ (terrible) plus _sauras_ (lizard).
As knowledge of these unusual reptiles increased through the discovery
of additional types and more complete and better preserved specimens, it
became evident that dinosaurs were neither a single group of reptiles
nor were all of them large. Actually the dinosaurs show as much
diversity in size, body form, and habits as any group of reptiles. The
smallest dinosaur walked on its 2 hind legs like a chicken and was about
the same size. The largest walked on all 4 legs, was about 80 feet long,
and weighed 30 to 40 tons. As examples of variety in body form there are
the two-footed, flesh-eating _Antrodemus_, the armored _Stegosaurus_,
the turtle-like _Ankylosaurus_, the horned _Triceratops_, the huge
_Apatosaurus_, the two-footed vegetarian _Camptosaurus_, and the great
variety of head forms in the aquatic hadrosaurs. Although there were two
distinct groups, we still retain the term “dinosaur” as a convenient
name for all of them but qualify it by saying, flesh-eating dinosaur,
plant-eating dinosaur, armored dinosaur, etc., to indicate the
particular type we are talking about. Perhaps you are wondering how all
these ancient creatures are related to reptiles in general. Where do
they fit in the classification system devised to bring order to this
mass of knowledge?