Miacids, pronounced as /maɪəsɪdz/, is a taxonomic group of extinct carnivorous mammals that lived during the Eocene epoch. The word "miacids" is derived from the word "Miacis," which is the type genus of the family Miacidae. It is said that "miacids" were the earliest carnivores to possess adaptations found in most modern carnivores, such as the ability to rotate their ankle joints. The spelling of the word "miacids" follows the English pronunciation rules, in which "c" is pronounced as /s/ when followed by "i, e, y."
Miacids are an extinct family of small carnivorous mammals that lived during the Eocene epoch, approximately 56 to 33.9 million years ago. They belong to the order Carnivora, which also includes modern-day carnivores such as dogs, cats, and bears. Miacids are considered to be one of the earliest relatives of modern carnivores.
These mammals were generally small in size, ranging from about the size of a weasel to that of a fox. With a slender body, long tail, and relatively short limbs, miacids likely had an appearance similar to modern-day mongooses. They had sharp, carnivorous teeth adapted for consuming meat, indicating their diet consisted mainly of small vertebrates.
Miacids are important in evolutionary history as they possess certain characteristics that link them to both carnivores and primitive tree-climbing mammals, potentially representing an early transitional phase in the development of modern carnivorous mammals. They are believed to have inhabited forested environments, adapting their limbs and claws for both arboreal and terrestrial locomotion.
Although miacids eventually went extinct, their lineages gave rise to various carnivorous mammal groups, including the progenitors of canids (dogs), felids (cats), and mustelids (weasels). Their existence provides valuable insight into the evolutionary processes that have led to the diversity of carnivorous mammals we observe today.
The word "miacids" comes from the combination of two words: "Miacidae" and the suffix "-ids".
"Miacidae" refers to a family of extinct carnivorous mammals. These mammals lived during the Eocene epoch, approximately 55 to 34 million years ago. The name "Miacidae" itself stems from the genus name "Miacis", which was coined by French paleontologist Edward Lartet in 1839. Lartet derived the word "Miacis" from the Greek words "μία" (mía), meaning "one", and "κύων" (kýōn), meaning "dog". This was in reference to the dog-like features observed in the fossil remains of this ancient mammal.