This metopa shows Perseus beheading Medusa in front of Athena, followed by the birth of Pegasus. It's part of the "small metopes" from the Temple C (540-510 BC).

The Small Metopes

Dating to 560-550 BC, but reused in the town walls of the Hellenistic period (4"-3" centuries BC), the "Small Metopes" represent the oldest examples of metopes (architectural element of the frieze consisting of a stone slab carved in relief and placed alternating with the triglyphs) which were documented in Sicily and Magna Graecia. Made from the soft and compact limestone of Menfi, the most commonly used material for stone sculpture in Selinunte, the metopes are distinguished by a very low relief, with the figures originally enlivened by the use of color. A total of six have been saved together with a dozen more fragments, divisible into two distinct groups according to the different manner in which the frame which surrounds the scenes was realized.

The first group (exhibited in the museum together with this group) includes: the metope of the Sphinx, one of the best-known ancient mythological creature, in which the monster is crouching in profile to the right ready to spring; the metope with the Rape of Europa by Zeus, in which the god, transformed into a bull, swam across the sea full of fish after having kidnapped the beautiful Phoenician princess; the relief of the Delian Triad, with the epiphany of Apollo who, playing the zither, reaches his mother Latona and his sister Artemis; the metope of the three deities, with vast ceremonial robes and headdress, variously identified with Demeter, Kore/Persephone, Hecate, with the Fates (the daughters of Zeus and Thetis, whose duty was to weave the thread of destiny of each man and finally cut it off, marking their death) or the Cariti (daughters of Zeus and perhaps Hera, personifications and dispensers of grace and beauty), or with Persephone and two companions collecting the flowers before her daughter Demeter's rape by Hades. The distinctive feature of this group of sculptures is the presence of the frame on all four sides, with equal height at the top and bottom.

The second group includes: the metope of the Quadriga, which depicts a chant departing with its team of horses, the outer ones of which are running away, led by two deities variously identified as Hera and Athena or Demeter and Kore/Persephone; and the metope, only partially preserved, showing Hercules fighting an opponent with a bull's body, identified with the Cretan bull or river god Achelous. The main distinctive feature of the frame of this second group of reliefs is the relationship between the lower band, which is higher, and the upper band.
The differences in the frame might exclude the attribution of the metopes of the two groups to the same frieze. The reliefs should rather be allocated to different sides (such as the two faces) of the same building, or to two separate buildings. In the latter case, the first group of metopes should be attributed to the so-called Temple Y, the first peripteros building (with columns around the cell) of Selinunte. On the contrary, the second group of metopes would be relevant to an unidentified temple of the same period, called x.