One challenge studying sleep evolution is that adequate sleep information is known only for two phyla of animals-chordata and arthropoda.
12.
The most familiar invertebrates include the Protozoa, Porifera, Coelenterata, Platyhelminthes, Nematoda, Annelida, Echinodermata, Mollusca and Arthropoda.
13.
The largest animal phylum is also included within invertebrates : the Arthropoda, including insects, spiders, crabs, and their kin.
14.
Evidence of varied origin and nature, though not qualitatively uniform in all Arthropoda, shows a trend in favour of such interpretations.
15.
There are however many other ranges of protelean organisms, such as early instars of certain species of mites that attack other Arthropoda.
16.
This article focuses on the segmentation of animal body plans, specifically using the examples of the taxa Arthropoda, Chordata, and Annelida.
17.
Schizocoelous development is typically attributed to protostomes : phyla Mollusca, Annelida, and Arthropoda, but some deuterostomes can exhibit schizocoely as well.
18.
The Ecdysozoa include the following phyla : Arthropoda, Onychophora, Tardigrada, Kinorhyncha, Priapulida, Loricifera, Nematoda, Loricifera, and Nematomorpha.
19.
Most species of Arthropoda with compound eyes bear just two eyes that are located separately and symmetrically, one on each side of the head.
20.
Within the Arthropoda, they belong in the subclass Acari ( or Acarina ) and species belonging to the Acari are informally known as acarines.
