Cancrinos differs most markedly from other related animals by the form of the second antennae, which are flattened towards the end, approaching the state seen in living slipper lobsters. Unlike living slipper lobsters, however, the flattened, distal parts of the antennae retain the
ancestral state of comprising many segments, rather than being reduced to a single element.
Development Because immature specimens have been found, parts of the
ontogeny of
Cancrinos are known, although it is unclear whether the smallest specimens are in the
puerulus stage, or are
juveniles. Younger specimens have less flattened antennae, more like those of living
spiny lobsters; thus,
Canrcinos exhibits a form of
heterochrony known as
peramorphosis. This ontogeny is thought to reflect the
phylogeny of
Cancrinos, representing a partial development from the ancestral spiny lobster-like form towards the derived slipper lobster-like form. ==References==