Question

Use the vertebrate lineage to how the skeleton changed and evolved to allow vertebrates to invade the land. . Include which classes contributed key features. • Include how each change benefited that lineage in terms of their evolution to land.

Answer 1

Mammalia- two pair limbs for various activities and presence of different types of teeth. Aves- forelimbs modified into wings, and hindlimbs modified for walking, swimming and clasping branches.fully ossified endoskeleton and pneumatic long bones. Reptilia- have got short neck and strong limbs than amphibia. Amphibia-evolvement of middle ear with 3 bones. Stegocephalia- Its legs are not well-suited to support its weight. The bones of its forearm, the radius and ulna, are very thin at the wrist and also unable to support it on land. It also lacks a sacrum and strong ligaments at the hip, which would be integral to supporting the animal against gravity. Osteichythes-replaced with bony endoskeleton. Chondrichythes- streamlined body with cartilagnous endoskeleton. - Cyclostomata- cartilaginous cranium and vertebral column Protochordata- notochord present only in larval tail for urochordate, in cephalochordate it is persistent throughout the life from head to tail.