BIOL 2030 Lecture Notes - Lecture 18: Devonian, Salamander, Terrestrial Animal
17 Sep 2015
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Document Summary
Viviparity common reproduce life young, young develop inside the female. Internal fertilization: unique for this class because most amphibians reproduce eggs by fertilization and larva develop completely independent of the parents. Majority are very small (~ 15 cm) but some are very large e. g. chinese giant. Carnivores predators as larvae and adult. ~ 5 000 species a lot are going extinct. Body plan considerably modified from basic ancestral form. Invasion of land began in the devonian period (400 mya: devonian period was completely dominated by fishes (aquatic vertebrates) nowadays 50% of vertebrates are fishes, devonian: mild temperatures and altering droughts and floods. Instead of relying on oxygen within an aquatic setting (water) if water is lost or reduced (water is not able to supply enough oxygen anymore) they can exploit aerial respiration. Important because gills are unsuitable for gas exchange in terrestrial environment (in air) In order for gills to work it requires hydrostatic support of water.
