Watch List notes:

Greek Italy. Southern Lucania, Sybaris. AR Triobol, c. 453-448 BC. D/ Poseidon advancing right, wielding trident; to right, ΣVB retrograde; to left, AP (?). R/ Bird (thrush?) standing right, within circular incuse. HN Italy 1744. SNG ANS 860. Kraay, Coinage pl. IV, 9. AR. g. 1.15 mm. 9.50 RR. Very rare and in excellent condition for issue. Prettily Toned. VF.

This coin is from the third foundation of Sybaris. The citizens of Laos played a role in this foundation, and Kraay believed the bird on the reverse was intended to be a laioV, a type of thrush, which served as a pun on the name of the city Laos.
(CNG 69, 52 note).