A number of major evolutionary innovations arose in the fish lineage. Check all of the evolutionary innovations associated with the fishes. a) Teeth arose from the rough scales of ancestral sharks.
b) Skeletal developments leading to the amphibian movement onto land probably evolved from lobe-finned fishes.
c) Fish fins are ancestral (homologous) structures to the flippers (forelimbs) of turtles.
d) The anterior gill arch formed the basis for the evolution of the vertebrate jaw.
e) The swim bladder ultimately led to the evolution of the amphibian urinary bladder.

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.