Definition of anapsid in US English:

anapsid

noun

Zoology
  • A reptile of a group characterized by the lack of temporal openings in the skull, including the turtles and their relatives.

    Sometimes placed in a subclass Anapsida, though this taxon is now often not recognized

    • ‘If anything, the synapsids seem more closely related to anapsids than diapsids.’
    • ‘The relationships of more basal anapsids are not firmly established, but millerettids apparently appeared first.’
    • ‘Today, only one group of anapsids remains (Chelonia - the turtles), which truly could be called an evolutionary success story.’
    • ‘Therefore, a long hiatus exists in the fossil record of anapsids.’
    • ‘All members of the group called the Reptilia, except for the anapsids (turtles and their ilk), and a few extinct groups, are diapsids.’

Origin

1930s: from modern Latin Anapsida, from Greek an- ‘without’ + apsis, apsid- ‘arch’.

Pronunciation

anapsid

/əˈnapsəd/