Vertebrate

A vertebrate is an animal with a spinal cord surrounded by cartilage or bone. The word comes from vertebrae, the bones that make up the spine. Animals that are not vertebrates are called invertebrates. Vertebrates include birds, fish, amphibians, reptiles, and mammals. The parts of the vertebrate skeleton are:

1. Braincase: A braincase or cranium protects the brain.
2. Vertebrae: A series of short, stiff vertebrae are separated by joints. This internal backbone protects the spinal cord. The joints between the vertebrae let the backbone bend.
3. Bones: support and protect the body's soft tissues and provides points for muscle attachment.
4. Gill arches: Gill arches in the pharynx of fish and some amphibians support the gills. In the majority of vertebrates some of the arches have evolved into other organs, such as jaws.

Vertebrate Temporal range: Cambrian Stage 3–Present, 518–0 Ma[1] PreꞒ Ꞓ O S D C P T J K Pg N
Example of vertebrates: Acipenser oxyrinchus (Actinopterygii), an African bush elephant (Tetrapoda), a Tiger shark (Chondrichthyes) and a River lamprey (Agnatha).
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Superphylum:	Deuterostomia
Phylum:	Chordata
Clade:	Olfactores
Subphylum:	Vertebrata J-B. Lamarck, 1801[2]
Infraphylums
Agnatha (paraphyletic) Gnathostomata
Synonyms
Ossea Batsch, 1788[2]

An alligator

Examples of vertebrates are mammals, birds, and fish. A few tens of thousands of species have been identified. The term "fish" is used to describe at least four different kinds of vertebrates.

Distinctions

Vertebrates dominate amongst the animals in virtually all environments. They include the largest animals in each main ecosystem, though not the largest living things (because that would include trees). They are the only animals which have an adaptive immune system.^[3] These two facts may be connected.

Taxonomy and classification

• Subphylum Vertebrata
  • Agnatha (jawless vertebrates)
    • Myxini
    • Hyperoartia (lampreys)
  • †Conodonta
  • †Pteraspidomorphi
    • †Thelodonti
    • †Anaspida
    • †Galeaspida
    • †Pituriaspida
    • †Osteostraci
  • Gnathostomata (jawed vertebrates)
    • †Placodermi (Paleozoic armoured forms)
    • Chondrichthyes (cartilaginous fish)
    • †Acanthodii (Paleozoic "spiny sharks")
    • Osteichthyes (bony fish)
      • Actinopterygii (ray-finned fish)
      • Sarcopterygii (lobe-finned fish)
      • Coelacanthimorpha (coelacanths)
      • Dipnoi (lungfish)
  • Tetrapoda (four-limbed vertebrates)
    • Amphibia (amphibians)
    • Amniota (amniotic eggs)
      • Sauropsida (reptiles and birds)
        • Lepidosauria (lizards, snakes and tuatara)
        • Testudines (turtles)
        • Archosauria (archosaurs)
          • Crocodilia (crocodilians)
          • †Pterosauria (pterosaurs)
          • Dinosauria (dinosaurs)
            • Aves (birds)
      • Synapsida (mammal-like tetrapods)
        • Mammalia

Related pages

• Invertebrate
• Vertebrate brain