neotenous
Adjective
Meaning
of or relating to or characterized by neoteny
Source: WordNetSynonyms
Examples
neotenic development
A prime example are their neotenous skulls. citation The shape of their skull does not change into adulthood; it only increases in size.
The neotenous individuals have higher survivorship as well as higher fecundity than the salamanders that had gone to the adult form in the higher altitude and cooler environment.
In humans "The cartoon of Betty Boop illustrates some human features which are sometimes labeled as neotenous, such as a large head, short arms and legs relative to total height, and clumsy, child–like movements."
This implies that proportionately large heads and proportionately short legs would be neotenous features for adults.