BSCI392
11-12-07
The Vertebrate Invasion of the Land

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Primitive sarcopterygian diversity:

Eusthenopteron: Represntative of a group of choanate fish ranging from the Devonian to the early Permian. Indicators of what the last fully aquatic ancestors of land vertebrates might have looked like. Fortunately, the anatomy of some, such as Eusthenopteron, is very well know from many excellent fossils.

Panderichthyes: This is an example of a small group of fish-like vertebrates even closer to the common ancestry of land vertebrates than Eusthenopteron:

Stegocephalii - transition to land:

Tiktaalik: (Dev) (As seen on Southpark!)

Biological meaning: Tiktaalik could absolutely support part of its weight on its forelimbs.

The biological significance of the invasion of land.

III. Roster of transformations.

Landmarks in evolution of terrestriality: