Miacis ("animal madre" en griego antiguo) es un género extinto de mamíferos carnívoros que forma parte de la superfamilia de los miacoideos, un grupo de mamíferos del Eoceno que posteriormente evolucionarían en los carnívoros modernos. Más concretamente, Miacis y otros miembros de su familia evolucionaron en los carnívoros caniformes, mientras que los feliformes encuentran sus orígenes en los viverrávidos. Aparecieron hace aproximadamente 55 millones de años, en el Eoceno muy temprano. Se extendieron por América del Norte y Eurasia, como lo demuestra el hecho de que se hayan encontrado fósiles en lugares tan variados como los Estados Unidos, Canadá, Bélgica, Francia, Kazajistán o China, y estaban adaptados para un estilo de vida arbóreo dentro de los bosques. Aún presentaban características típicas de otros carnívoros primitivos como los creodontos, como por ejemplo sus cráneos bajos, largos cuerpos esbeltos, colas largas y patas cortas. Probablemente se extinguieron hace 42 millones de años, en el Eoceno Medio, pero se han descubierto fósiles del Eoceno Superior (hace aproximadamente 36 millones de años) que han sido tentativamente referidos a este género.

Leer el artículo completo en Wikipedia · CC-BY-SA

Miacis is a genus of extinct carnivorous mammals that appeared in the late Paleocene and continued through the Eocene. The genus Miacis is not monophyletic but a diverse collection of species that belong to the stemgroup within the Carnivoramorpha. As such, most Miacis species belong to the group of early carnivores that represent the ancestors of the modern order, the crown-group Carnivora. However, the species Miacis cognitus is placed not in the stem-group but among the Caniformia, one of the two suborders of the crown-group Carnivora. Miacis species were five-clawed, about the size of a weasel (~30 cm), and lived on the North American and European continents. They retained some primitive characteristics such as low skulls, long slender bodies, long tails, and short legs. Miacis retained 44 teeth, although some reductions in this number were apparently in progress and some of the teeth were reduced in size. The hind limbs were longer than the forelimbs, the pelvis was dog-like in form and structure, and some specialized traits were present in the vertebrae. It had retractable claws, agile joints for climbing, and binocular vision. Miacis and related forms had brains that were relatively larger than those of the creodonts, and the larger brain size as compared with body size probably reflects an increase in intelligence. Like many other early carnivoramorphans, it was well suited for an arboreal climbing lifestyle with needle sharp claws, and had limbs and joints that resemble those of modern carnivorans. Miacis was probably a very agile forest dweller that preyed upon smaller animals, such as small mammals, reptiles, and birds, and might have also have eaten eggs and fruits.

Leer el artículo completo en Wikipedia · CC-BY-SA