Chapter 11 The Triassic Takeover

P. 139. Diapsids

UC Berkeley's Introduction to the diapsids
Tree of Life guide to the diapsids

P. 139. Basal Diapsids

Heleosaurus was terrestrial, Hovasaurus was aquatic, and Coelurosauravus was a glider. (More information from the Royal Ontario Museum).

P. 140. Lepidosauromorphs

Lepidosauromorphs from the Tree of Life site.

Lepidosaurs:

Squamata are the numerous and diverse smaller living reptiles, including lizards and snakes.
- Squamata from the Tree of Life site
- Check out the computer images of lizard skulls at the University of Texas CT scanning lab.
- The digestive physiology of the python, for those who might think that snakes are rather primitive.
Sphenodontia are a sister group of the Squamata but include only one family with one living form, the tuatara Sphenodon.
- Tuataras here with links to other pages.

P. 141. Archosauromorphs

Here is UC Berkeley's Introduction to the diapsid archosauromorphs

Archosauria are conveniently divided into four groups. Thecodonts; Crocodylia; Dinosauria; and Pterosauria.

Some early diapsid reptiles are not properly understood, including Mesosaurus, a strange little Permian fish-eating reptile that was the earliest amniote to reach the southern continents.

Mesosaurus
Another specimen of Mesosaurus, from Reisz's site at the University of Toronto.
Here is a reconstruction of Mesosaurus.

The Triassic Diapsid Takeover

Lecture notes on the Triassic World
Yale's Peabody Museum Panorama from the Triassic, with background discussion.
The crocodylomorph Effigia

P. 143. Respiration, Metabolism, and Locomotion

P. 144. The Komodo dragon

The giant varanid lizard, the ora or Komodo dragon: short piece from the American Museum of Natural History. More stories:

Basic facts about the Komodo dragon
Great article by Jared Diamond in Discover, December 1992
The gulping that helps a monitor breathe in the face of Carrier's Constraint. Article by Adam Summers, originally published in Natural History, June 2003.
Feature article from Scientific American , March 1999.
How to catch a Komodo dragon: first catch a goat...
Saliva from the Komodo dragon. Article from National Wildlife Magazine, 2003.
Sharon Stone and the Komodo dragon. You can't make up stuff like this!

P. 146. Archosauromorphs

A student finds a new Late Triassic rauisuchian in North Carolina, announced August 1999.
Skull of the Late Permian predatory thecodonts, the oldest known thecodont Archosaurus
and the lion-sized Garjainia

Dinosaur Ancestors

Euparkeria could have been the ancestor of both pterosaurs and dinosaurs later in the Triassic.

Here is a dynamic image of the anatomy and posture of Euparkeria

The first dinosaurs may have appeared right at the Middle/Upper Triassic boundary:

Story from BBC News OnLine, Thursday, October 21, 1999.
Press release: these are Middle to Late Triassic, from Madagascar, very slightly older than than the Argentine ones, perhaps 230 Ma. We are not talking scientific breakthrough here. 22 October 1999.

The reference list for Chapter 11, 4th Edition, with associated Web links

Page last updated December 5, 2006.

Links last checked October 3, 2005.

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