BIOL-3030 Lecture Notes - Lecture 12: Pedicellate Teeth, Lissamphibia, Gymnophiona
Document Summary
Caecilians - clade gymnophiona about two hundred species. Salamanders - clade urodela about six hundred species. Frogs - clade anura about six thousand species. Smooth, glandular skin (highly permeable, no armor) They contain a mucus gland and a poison gland. The mucus gland is closer to the skin and empty round looking. Poison gland is deeper and filled with little dots. Frogs start off as eggs in the water as tadpoles. Then they continue to grow and their tail shortens and legs amerge. They then walk onto land and continue their life as a land vertebrate. Direct development ( eggs are laid and out emerges a full formed frog on land) Fossil record to jurassic, today they live in tropics worldwide. Smaller than 1 foot and they are specialized for burrowing. Highly ossified (solid bony) skulls, their jaws produce high biting forces. Reduced eyes, special chemosensory organ (because they live underground) organ is called a tentacle.
