Olbian dolphins are among the world's first bronze coins. Years of minting
VI century BC - IV century BC.
An essential feature of Olbian dolphins is the presence of large specimens among them. Such dolphins were issued as a paradigm of denominations. Dolphins have different weights: 2.5 grams, 14.9 and 28.2 grams, 71.5 grams, but the most common are 2.5-3 grams.
It is difficult to catch a common stylistic system among dolphins. In addition, these coins are poorly classified by denomination: the largest coins of this variety are so rare and so different in weight (from 103 to 58 grams) that they cannot be unequivocally placed in a weight relationship either with the cast round coins of Olbia or with small dolphins, which weigh from 4 to 6.5 grams.