selkäjänteisihin
Selkäjänteiset is the Finnish term for chordates, a phylum of animals that includes vertebrates and several related invertebrate groups. The defining characteristic of chordates is the presence of a notochord, a flexible rod that supports the body, at some stage of their life cycle. In many chordates, the notochord is replaced by a vertebral column during development, forming the backbone of vertebrates.
Other key features shared by all chordates include a dorsal hollow nerve cord, pharyngeal slits, and a
The phylum Chordata is divided into several subphyla. Cephalochordata, such as lancelets, retain the notochord throughout