Anamorphosis is encountered the following insect order

Anamorphosis is encountered in the Protura insect order.
Anamorphosis refers to postembryonic development and moulting in Arthropoda that results in the addition of abdominal body segments, even after sexual maturity. Examples of this mode of development occur in proturans and millipedes.
Protura hatch with only 8 abdominal segments and add the remaining 3 in subsequent moults. These new segments arise behind the last abdominal segment but in front of the telson.