Afrotheria

Part of speech: noun

Definitions

1. A clade of mammals that includes elephants, manatees, and hyraxes, characterized by unique evolutionary traits and genetic markers
2. A taxonomic group encompassing diverse animals like sea cows and elephants, recognized for their shared ancestry and traits distinct from other mammals
3. A lineage of mammalian species including both large and small creatures, linked by evolutionary history and a set of defining morphological features

Etymology: Afrotheria was coined in 1998, when molecular biologists analysing DNA sequences found that a surprising group of mammals shared a common ancestor. The name combines "Africa" with the Greek "therion," meaning "wild beast," and it reflects the fact that most living members, including elephants, sea cows, aardvarks, elephant shrews and tenrecs, are native to Africa or descend from African lineages. Because the grouping was discovered through genetic data rather than anatomy, the name records a finding about ancestry rather than a shared body plan. The surprise was that these animals looked unrelated. Elephants, manatees and golden moles have little in common on the surface, so zoologists had long placed them in separate orders. Gene sequences showed they belonged to one clade, which later work suggested had split off from other placental mammals in the Cretaceous period, with the continent's long isolation likely helping to explain how so many distinct forms developed there.