Zoology What lineage do the sarcopterygian fish and actinopt

Solution

First we have to find the lineage of the sarcopterygian fish and actinopterygian fish that which both give rise too because of the sarcopterygians the coelacanth has lobe-fins muscular fins with a single bone that articulates with the rest of the body many fishes we have seen they have several bones at the bases of their pectoral fins and their fins are composed of a set of webbed rays not muscle and skin covered bone lobe fins are rare among living fish and are only possessed by the coelacanth and lungfish.

while,fish appear in the fossil record earlier than the clade we call tetrapods does it\'s tempting to assume that modern fishes bear the same traits that their and our common ancestor did this line of reasoning is intuitive but it is not correc.

The fish from the fossil record are represented by a group of small jawless armoured fish known as ostracoderms.

The first jaws are found in Placoderm fossils the diversity of jawed vertebrates may indicate the evolutionary advantage of a jawed mouth.

Jawless fish were prominent among the early fish in the early Paleozoic, fish jaws are bony or cartilaginous and oppose vertically comprising an upper jaw and a lower jaw.