Chordates are vertebrates that include mammals, fish, lizards, frogs, and birds, with an estimated 50,000 living species. The Phylum Chordata evolved about 539 million years ago, based on current evidence. Characteristics of Chordates generally include a notochord (often becomes the vertebral column), dorsal nerve, gill clefts (often only during embryo stage), segmented muscles, and a tail.
Kingdom: Animalia
-Phylum: Chordata
I have photographed six classes of Chordata so far:
–Chondrichthyes (Cartilaginous Fish)
–Osteichthyes (Bony Fish)
–Amphibia (Amphibians)
–Reptilia (Reptiles)
–Aves (Birds) – redirects to the alphabetic bird list
–Mammalia (Mammals)