GEOL 104 Dinosaurs: A Natural History
Fall Semester 2006
The History of Prehistory: Dinosaur research through time
First major dinosaur discovery, in Britain, by Reverend William Buckland:
- Megalosaurus (“big lizard”)
- Formally described it in 1824
- Thought it to be a giant version of the modern monitor lizard
Next major discovery, in the Weald region of southern England, by husband and wife team
Dr. Gideon and Mary Ann Mantell:
- Teeth were leaf-shaped, reminiscent of the modern Iguana, a primarily
- Called it Iguanodon (“iguana tooth”)
- Formally described it in 1825
- Imagined it to be an immense version of the iguana lizard
Third major discovery, also in the Weald region and also by the Mantells:
- Very large spikes were found arranged along the skeleton: first evidence of giant
- Called it Hylaeosaurus (“lizard of the Weald”)
described in 1833
- Pictured it as a giant spiky lizard
Other discoveries were made on the European continents in the 1830s and 1840s.
In 1841, Sir Richard Owen gave public talks about the fossil reptiles of Britain.
Concluded that Megalosaurus, Iguanodon, and Hylaeosaurus formed their
own distinct group. Proposed the name Dinosauria (“fearfully great lizards”) for
this group when he wrote up talk (in 1842)
In the 1850s the Great Exposition. Benjamin Waterhouse Hawkins sculpted Megalosaurus, Iguanodon, and
Hylaeosaurus (and other non-dinosaurs) under Owen’s guidance. Dinosaurs became
popular subjects for popular science, political cartoons, etc.
Early North American discoveries:
- Three toed footprints in the Connecticut River Valley, thought to be giant bird tracks
- Fragmentary skeleton (also from Connecticut), thought to be “Indian skeleton”
- Dinosaur teeth found by explorers in western territories (now Montana):
- Described in 1856 by first American vertebrate paleontologist Joseph Leidy
- Recognized some to be similar to Iguanodon, others to be similar to
Megalosaurus, still others to be some sort of lizard
In 1858, first major North American dinosaur fossil:
- Discovered near Haddonfield, New Jersey
- Described by Leidy, who named it Hadrosaurus (“heavy lizard”)
- Teeth and bones were similar to Iguanodon, but fossil was more complete
- Front leg was much smaller and more slender than hindlimb, indicating it was
bipedal (two legged)
- Suggested that Iguanodon was bipedal, too
First recognition of bipedal dinosaurs. In 1866, another New Jersey discovery (this time of bipedal
meat-eater) described by Edward Drinker Cope of Philadelphia. Eventually named
Major important rivalry between Cope and Othniel Charles Marsh of Yale University:
The vast numbers of fossils discovered formed the central collections of major museums and
greatly increased the knowledge of extinct life (including some of the first complete
In Europe, new discoveries were also being made:
- First complete Iguanodon skeletons
- First small dinosaurs (Compsognathus, Hypsilophodon)
Beginning of 20th Century, new, wealthy museums sponsored major expeditions to American West.
Also, the AMNH and various European museums began the era of imperial paleontology
(major expeditions to foreign lands, to bring fossils back to the home institution)
In the 1920s, beginning of Great Depression and WWII led to decline in large scale
- Most famous AMNH expeditions: the Central Asiatic Expeditions of the 1920s
- From 1907-1912, German expedition to Tendaguru, German East Africa (now Tanzania)
- Various digs in other parts of the world by other museums (e.g., Germans in Egypt, various
U.S. and Canadian museums in Alberta, etc.)
Also, dinosaur science began to lose its scientific appeal.
In 1960s, John Ostrom of Yale University:
- Reinterpreted horned and duckbill dinosaurs as sophisticated feeders
- In 1964, discovered Deinonychus (“terrible claws”) (named in 1969)
- Sickle-like claw on foot indicated active leaping predator
- Later comparisons between Deinonychus and the primitive bird Archaeopteryx
caused Ostrom to revive idea that dinosaurs were bird ancestors
1970s: Beginning of the Dinosaur Renaissance. New (or revived) topics of dinosaur
New discoveries from many parts of the world
- Were they cold-blooded or warm-blooded?
- Did they have complex family structures?
- How did they communicate?
- How were the different types of dinosaur interrelated?
- What was the relationship between dinosaurs and birds?
- How did the dinosaurs go extinct?
New techniques to find, uncover, prepare, and describe fossils
- Now discoveries made from every continent
- Discoveries often done by international teams, included paleontologists from
Remainder of the course represents the work of Ostrom’s colleagues and students
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Last modified: 14 July 2006