The unifying characteristic of chordates (Phylum Chordata) is the presense of a notochord (an internal skeletal rod that provides support) during some stage of the animal's development. Although the majority of chordates are vertebrates (animals whose notochord is replaced during development with interlocking vertebrae), there are also two groups of chordates that are invertebrates.
Chordates also exhibit the following characteristics:
- bilateral symmetry
- body segmentation
- endoskeleton (bony or cartilaginous)
- pharyngeal pouches (present during some stage of development)
- complete digestive system
- ventral heart
- closed blood system
- tail (at some stage of development)
Classification:
- Kingdom Animalia
- Superphylum Deuterostomia
- Phylum Chordata
New to animal classification? Find out more about how scientists classify animals.
Sources:
- Burnie, D. and D.E. Wilson. Animal. Dorling Kindersley. London. 2001.
- Myers, P. 2001. 'Chordata' (On-line), Animal Diversity Web. Accessed August 23, 2005.
- 'Chordate' (On-line), Wikipedia. Accessed August 23, 2005.
