PHYLUM CHORDATA (MAMMALS, BIRDS, RETILES, AMPHIBIANS, FISH)
FOUR COMMON FEATURES
This phylum includes animals with a notochord, pharyngeal slits, dorsal nerve cord, and post anal-tail (which they have at some period in their life).
Dorsal hollow nerve cord - nerve fiber bundle that runs down the back and connects the brain with other organs and muscles.
Notochord - a cartilaginous, skeletal, flexible rod on the dorsal side of the gut. It is present at one stage in all chordates.
Pharyngeal slits - A set of openings that connect the throat (inside) to the outside (neck). Sometimes used as gills in fish. Become the bones of the inner in in some chromates, like humans.
Post-anal tail - body extension past the anal opening. Remnants of the human tail are evidenced by the presence of the coccyx. Too bad we aren't like some primates with their prehensile tails. The struggle is truly real.
There are six classes main of chordates. There are more than 75,000 species. They include most vertebrates, so they have backbones, but some are invertebrates (like tunicates). Humans are chordates. This is the most highly evolved, complex and complicated group of animals. They have the most advanced brains and nervous systems, for example.
THE SIX CLASSES OF CHORDATES
CLASS CHONDRICHTHYES
CLASS OSTEICHTHYES
CLASS AMPHIBIA
CLASS REPTILIA
CLASS AVES
CLASS MAMMALIA
PLEASE SEE THE FOLLOWING PAGES FOR INFORMATION ABOUT EACH CLASS.
This phylum includes animals with a notochord, pharyngeal slits, dorsal nerve cord, and post anal-tail (which they have at some period in their life).
Dorsal hollow nerve cord - nerve fiber bundle that runs down the back and connects the brain with other organs and muscles.
Notochord - a cartilaginous, skeletal, flexible rod on the dorsal side of the gut. It is present at one stage in all chordates.
Pharyngeal slits - A set of openings that connect the throat (inside) to the outside (neck). Sometimes used as gills in fish. Become the bones of the inner in in some chromates, like humans.
Post-anal tail - body extension past the anal opening. Remnants of the human tail are evidenced by the presence of the coccyx. Too bad we aren't like some primates with their prehensile tails. The struggle is truly real.
There are six classes main of chordates. There are more than 75,000 species. They include most vertebrates, so they have backbones, but some are invertebrates (like tunicates). Humans are chordates. This is the most highly evolved, complex and complicated group of animals. They have the most advanced brains and nervous systems, for example.
THE SIX CLASSES OF CHORDATES
CLASS CHONDRICHTHYES
CLASS OSTEICHTHYES
CLASS AMPHIBIA
CLASS REPTILIA
CLASS AVES
CLASS MAMMALIA
PLEASE SEE THE FOLLOWING PAGES FOR INFORMATION ABOUT EACH CLASS.