Scientists consider lancelets the closest living relatives to vertebrates (VER-teh-brehts), or animals with a backbone. The two groups share traits such as the organization of the main body muscles into separate segments and the organization of the blood vessels. Lancelets also have a structure that is a simple form of the liver of vertebrates. The nerve cord of lancelets has a central canal that is enlarged at the head end, making it similar to parts of the vertebrate brain.
User Comments Add a comment…