mammallike

Mammallike is an adjective used to describe organisms, features, or forms that resemble mammals in appearance or function, without implying membership in the clade Mammalia. The term appears in biology, paleontology, and science fiction as a way to indicate similarity rather than strict classification.

In biology, mammallike traits may include body hair or a hair-like covering, endothermic metabolism, lactation, and mammary glands in females. Other commonly cited features are differentiated teeth and certain jaw or skull adaptations that are characteristic of mammals. The label does not by itself prove a taxonomic relationship.

In paleontology, "mammallike" has historically been used for "mammal-like reptiles," a now outdated phrase. The more accurate term is synapsids, a lineage closer to mammals than reptiles proper. Among synapsids, groups such as cynodonts show progressive mammal-like traits, including refined teeth, changes in jaw mechanics, and the emergence of traits associated with mammalian hearing and, in later relatives, more advanced mammalian features.

In popular usage, mammallike can describe fictional creatures or robots designed to resemble mammals or to evoke mammalian physiology, often in a speculative or illustrative context. Etymologically, the word combines mammal with the suffix -like, signaling resemblance rather than taxonomic status. See also mammal, synapsid, endothermy, and lactation.