OLD SOFTIES

The image below is a photo of the exhibit panel. Following it is a transcript of the panel.

Photo of the panel from the exhibit.

The first known animals had soft bodies, shaped in one of three body plans

Ediacaran animals had the same basic body plans that we see in modern animals. Body plans are described in terms of symmetry : radial, bilateral, or none (asymmetrical). Most Ediacaran animals show radial symmetry.

PICTURE CAPTIONS:

asymmetry:
irregular body plan, as seen in sponges, which have

  • specialization of cells for different specific functions, such as feeding or digestion
  • a porous body wall that filters food particles from sea water

radial symmetry:
regular body plan formed of a repeating pattern of similarly shaped parts around a center, as seen in sea anemones, which have

  • a non-porous wall that encases the body

  • single-opening gut for ingesting food, excreting waste

  • tentacles for capturing and manipulating food

bilateral symmetry:
regular body plan in which one half of the body mirrors the other, as seen in flatworms, which have

  • a directional body with a head

  • complex reproductive system