Animal diversity II

• Deuterostomes. In development of cells there is an opening that forms which begins at the anus and then forms the mouth.
• Deuterostomes include invertebrates and vertebrates.
• Lophotrochozoa

  Consists of molluscs.
• Ecdysozoa.

  Consist of Arthropoda
• Main features of Deuterostomia: bilateral symmetry - triploblastic; consisting of ectoderm, endoderm, mesoderm. And first opening develops in the anus first.
• Deuterostomes have two main phyla including: Echinoderms and chordates.
• Echinoderms are animals like sea stars and sea urchins etc.
• Chordates are animals like fish, amphibians, and turtles.
• Echinoderms: (sea stars, sea urchins)

  Echinos = spiky

  derma = skin
• Echinoderms are generally slow-moving or sessile animals, meaning fixed to a surface.
• Examples of echinoderms: Sea stars (starfish), Brittle stars, Sea urchin, Sea cucumbers.
• The phylum Chordates have 4 features that happened at some stage of our development. They include: Pharyngeal slits or clefts, Post-anal tail, Notochord, and a Dosal, hollow nerve cord.

  They happened during the embryo development!
• Name the 4 features of chordates.

  Pharyngeal slits, Notochord, Post-anal tail, Dorsal hollow never cord
• Notochord.

  Notochord is not the same as the nerve cord.

  It has a flexible rod which gives it rigidity, and is located along the back of the body under the nerve cord.

  It provides support. The structure where things can move on.
• What is a Notochord?


  A notochord is a flexible rod that provides support.
• Dorsal, hollow nerve cord.

  The nerve cord is a part of the nervous system. It develops into the spinal cord and brain.
• Pharyngeal slits or clefts.

  They are slits that opened into the digestive tract where water was able flow through them which could be used for filter feeding (to capture food).

  In non-tetrapod vertebrates aka. fish, they develop into gills.

  In tetrapods (four limbed vertebrates) aka. humans, they develop into ears and necks.

  *Basically at some of development we had pharyngeal slits.
• Muscular post-anal tail.

  Our ancestors would have had an extended tail but in evolution, humans no longer have tails because they don't need them.

  The tail is muscular, consisting of muscles -> movement.
• Chordates have two major groups: Lancelets and Tunicates
• Deuterostomes


  Have two phyla: Echinoderms and Chordata
• Echinoderms


  Animals that are slow-moving or fixed to a surface
• Echinoderms


  • starfish
  • sea urchins
  • sea anemones
• Chordates


  • Notochord
  • Pharyngeal slit (develops into gills in fish, while ear & neck in human)
  • Dorsal hollow nerve cord
  • Muscular post-anal tail (muscle tail that develops depending on the animal - relates to evolution, humans may have had tails millions of years ago but have developed to not need tails in the adult form. Other animals still have tails even after evolution for specific reasons like balancing. Amphibians have a muscular post-anal tail in their tadpole or larvae stage however tail disappears when developed into its adult form)
• Chordata classes that are invertebrates

  • Lancelets
  • Tunicates
• Features of Lancelets and Tunicates.

  Lancelets: appear like fish but don't have bone and filter feeds

  Tunicates: sessile (non-moving), visible chordate features in larva stage