GEOL 104 Dinosaurs: A Natural History

Fall Semester 2013
Introduction: What are Dinosaurs? What is Science? The Meaning of Fossils

Review course policies, syllabus.

Goals of this course:

Learning Outcomes: By the end of the semester, every student should be able to:

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. The majority of paleontologists, or even of vertebrate paleontologists, are NOT dinosaur researchers!

Dinosaur fossils have been found in Mesozoic Era rocks from every continent, including Antarctica.

Types of dinosaur fossils:

The word "Dinosauria" (and hence "dinosaur") was coined in 1842 by Sir Richard Owen:

Owen recognized 3 different dinosaurs:

Saw that they were different from other fossil (and modern) reptiles because of:

Dinosauria is now recognized as a single major group of organisms, all descendants of a common ancestor.

Modern Definition of Dinosauria:

The concestor (most recent common ancestor) of Megalosaurus and Iguanodon and all of its descendants

Thus, dinosaurs are not just "any fossil animals" or "all fossil reptiles" or "all fossil reptiles of the Mesozoic" or "all giant fossil reptiles of the Mesozoic." Instead, they are specific branch of the Tree of Life.

What is Science?

The following (from Thomas Kida's Don't Believe Everything You Think) are a useful set of characteristics of thinking like a scientist:

The Meaning of Fossils
Dinosaur fossils have been weathering out of the rock since LONG before humans evolved, yet "Dinosauria" was not recognized until 1842. Why did it take this long?

Before scientists could recognize the existence of dinosaurs, they had to recognize that fossils were the remains of dead (not alive), unknown, extinct (not living anywhere) organisms.

Traditional cultures around the world noticed fossils, but assumed they were remains of supernatural creatures (giants, trolls, mammuts (a Siberian [Yakut] legendary race of "earth dwellers": the name is now transferred to fossil elephants!), unicorns, dragons, etc.).

During the Renaissance and Enlightenment in Europe, many thinkers began to abandon a view of the mythic past that included monsters and dragons. So what might fossils be? Some explanations included:

Nicolas Steno, a 17th Century naturalist, came up with a simple solution: fossils really WERE parts of dead animals and plants! Steno was one of the first people to recognize that rocks were not eternal, but were formed during the history of the Earth. So fossils were the remains of living things buried as those rocks formed. But what sort of animals were represented by fossils?

Baron Georges Cuvier (France) and contemporaries examined many fossils in the late 1700s/early 1800s:

The stage was set for the discovery of dinosaurs.

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Last modified: 26 August 2013