The Amniote Radiation

• Comparison of skull characteristics of major amniote groups
• Tree of Life guide to the Amniotes: updated 2000.
• Phylogeny and classification of amniotes, updated 2000.

Synapsids

Synapsid overviews on the Web:

• Tree of Life guide to the Synapsids
• The skeletal novelties of Main Synapsid Lineages

Pelycosaur Biology and Ecology

P. 126. Carnivorous Pelycosaurs

• The sphenacodonts from the Palaeos site.
• American Museum of Natural History specimen of Dimetrodon
• Image of Dimetrodon grandis
• Make a Cut-out Dimetrodon

P. 128. Vegetarian Pelycosaurs

• Caseids were more numerous than edaphosaurs. They included Ennatosaurus from Russia.
• Edaphosaurs

P. 130. Thermoregulation in Living Reptiles

Examples of Heterothermy in Animals

P. 131. Thermoregulation in Pelycosaurs

P. 132. Permian Changes

Therapsid Evolution

P. 134. Dinocephalians

Tapinocephalians. Here is a picture of the skull of Estemmenosuchus.

Tusks, sexual dimorphism, and inferred display/fighting in a Permian therapsid from South Africa. Press release, January 24, 2003.

P. 135. Theriodonts dominated the early Late Permian of Russia.

• Here is a poor photograph of the skull of the sabertooth theriodont Eotitanosuchus.
• Artist's reconstruction of Titanophoneus

P. 135. Gorgonopsians were specialist carnivores on large prey and had some exciting adaptations. Here is an image of the gorgonopsian Rubidgea.

In late 1998 the first complete skeleton of a gorgonopsian was found in South Africa. We have to wait until the fossil is cleaned before we can assess the paleobiology of gorgonopsians better.

P. 135. Cynodonts are the therapsids from which mammals evolved. They were important small- and medium-sized animals in Triassic times throughout Gondwanaland.

• Here is the predatory Cynognathus

• Here is a dicynodont from Russia.
• Dicynodonts declined abruptly at the end of the Permian, but a few lineages persisted, often in great numbers. The best-known dicynodont of all is Lystrosaurus:
  • Skull of Lystrosaurus from South Africa
  • Lystrosaurus at National Geographic
  • Are these Lystrosaurus footprints?

  What happened to the dicynodonts? We know what C. E. Gow thought. Gillian King wrote all around this question in 1990, but in the end decided that we don't know.

  The reference list for Chapter 10, 4th Edition, with associated Web links

  Page last updated June 7, 2004.

  Links checked October 2, 2005.

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