anapsid

Examples of anapsid in the following topics:

• Evolution of Amniotes

  • Sauropsids include reptiles and birds and can be further divided into anapsids and diapsids.
  • Anapsids have no temporal fenestrae, synapsids have one, and diapsids have two.
  • Anapsids include extinct organisms and may, based on anatomy, include turtles (Testudines), which have an anapsid-like skull with one opening.
  • The image illustrates the differences in the skulls and temporal fenestrae of anapsids, synapsids, and diapsids.
  • Anapsids have no openings, synapsids have one opening, and diapsids have two openings.

• Evolution of Reptiles

  • Soon after the first amniotes appeared, they diverged into three groups (synapsids, anapsids, and diapsids) during the Permian period.
  • These groups remained inconspicuous until the Triassic period when the archosaurs became the dominant terrestrial group due to the extinction of large-bodied anapsids and synapsids during the Permian-Triassic extinction.