An epiphysis (from Ancient Greek ἐπί (epí) 'on top of' and φύσις (phúsis) 'growth'; pl.

: epiphyses) is one of the rounded ends or tips of a long bone that ossify from one or more secondary centers of ossification.

[7] However, the secondary center of ossification may have evolved multiple times, having been found in the Jurassic sphenodont Sapheosaurus as well as in the therapsid Niassodon mfumukasi.

As the longest bone in the human body, it plays a pivotal role in forming the upper part of the knee joint.

The tibia, located medially, bears most of the body's weight, while the fibula, positioned laterally, is smaller and supports leg structure.