A fossil analysis suggests that the yunnanozoan, a wormlike fish that flourished around 520 million years ago, sported structures that were the precursors of the head and jaws of modern vertebrates.

He doesn't even have a head. If Blob had been born with a spine, or backbone, he would have been a vertebrate. If we give Blob some legs and a head then he can start to move about. There are lots ...

Model vertebrates are extensively studied non-human vertebrates (species with a notochord, or vertebral column) chosen for the ease of investigating particular biological phenomena in areas such ...