Synapsids

Linnaean and cladistic classifications

Synapsids were subsequently considered to be a later reptilian lineage that became mammals by gradually evolving increasingly mammalian features, hence the name "mammal-like reptiles" (also known as pelycosaurs). These became the traditional terms for all Paleozoic (early) synapsids. More recent studies have debunked this notion as well, and reptiles are now classified within Sauropsida (sauropsids), the sister group to synapsids, thus making synapsids their own taxonomic group.