GEOL 104 Dinosaurs: A Natural History
Fall Semester 2006
Introduction: What is Science?; What are Dinosaurs?
Review course policies,
- Is NOT simply a body of knowledge
- Is a way of understanding the physical universe
- Uses the method of testing hypotheses
- Observations of natural phenomena lead to possible explanations (hypotheses)
- These hypotheses must be falsifiable (i.e., there must be some test, experiment, or observation which can demonstrate that the hypothesis is untrue)
- Until the hypothesis is tested, it is only considered a speculation
- If the hypothesis survives a test (or tests) of falsification, it is tentatively (or provisionally) accepted (keeping in mind that additional tests might potentially overturn the hypothesis)
- Proceeds by publication of ideas
- Allows others to check the original scientist's observations
- Allows others (including later generations) to independently test the hypotheses
- Allows ideas to be widely transmitted
Dinosaur science is NOT Archaeology!
Paleontology, the study of ancient life and their remains (fossils).
Fossils (from Latin fossilium "that which is dug up") are the physical
remains of past life and its activities preserved in the rock record.
Vertebrate Paleontology, the study of ancient backboned animals, including dinosaurs
Dinosaur fossils have been found in Mesozoic Era rocks from every continent, including Antarctica.
Types of dinosaur fossils:
- Isolated bones and teeth
- Skeletons, in varying degrees of completeness
- Footprints and trackways
- Skin impressions and Feathers
- Mineralized soft tissue (muscles, intestines, possible heart)
- Eggs (some with embryos) and nests
- Coprolites (fossilized feces)
The word "Dinosauria" (and hence "dinosaur") was coined in 1842 by Sir Richard
- Greek deinos "fearfully great" (i.e., not just big, but SCARY BIG!), and sauros "lizard"
- Note: hundreds of books to the contrary, Owen did not say Dinosauria meant
Owen recognized 3 different dinosaurs:
- carnivorous Megalosaurus
- herbivorous Iguanodon
- armored Hylaeosaurus
Saw that they were different from other fossil (and modern) reptiles because of:
- upright limbs
- extra hip vertebrae
- and a few other skeletal features
Dinosauria is now recognized as a single major group of organisms, all descendants of a
Modern Definition of Dinosauria:
All descendants of the concestor (most recent common ancestor) of Megalosaurus and
To Next Lecture.
Last modified: 14 July 2006