Bilateraalse
Bilateria, also known as bilaterian animals, is a large clade that includes most animal life. They are characterized by bilateral symmetry at some life stage, a triploblastic body plan with three germ layers (endoderm, mesoderm, ectoderm), and typically a centralized nervous system and a complete digestive tract with a mouth and an anus. Most bilaterians exhibit cephalization, the concentration of sensory organs at the front end.
Taxonomically, Bilateria is divided into two major divisions: Protostomia and Deuterostomia. Protostomes encompass ecdysozoans (such as
Evolution and fossil record: Bilaterians likely originated in the Neoproterozoic era, with the urbilaterian posited as
Diversity and ecology: Bilaterians occupy nearly every habitat and include representatives from microscopic worms to large