Sphenacodontidae (Greek: "wedge point tooth family") is an extinct
family of small to large, advanced,
carnivorous,
Late Pennsylvanian to
middle Permian pelycosaurs. Primitive forms were generally small in size (60 cm to 1 meter), but during the later part of the early Permian these animals grew progressively larger (up to 3 meters or more), to become the
top predators of their environments. Sphenacodontid fossils are so far known only from
North America and
Europe.
