Allegory of the sea, with two fish tails
In my search for mythical women with two mermaid tails, I’ve found only two ancient examples that don’t have a proper name, unlike the Scythian ancestral goddess, Scylla, or the Gorgons. One is the two-tailed ‘tritonesses’ from the Temple of Despoina at Lykosoura, in modern day Arcadia, Greece.
The second twin-tailed woman is from the Sebasteion reliefs, from the ancient city of Aphrodisias, a temple and sanctuary complex dedicated to Aphrodite, and to Roman emperors. The temple was made between 20 and 60 CE and is in modern-day Turkey.
Allegory of the Sea, Sebasteion reliefs, ancient city of Aphrodisias. Made around 20-60 CE. Image via Flickr.
The woman in question is simply known as an “allegory of the sea.” Like the tritonesses, she has a leaf or fin skirt, and her tails curl off to her sides. Here’s her description from an article about the temple excavation:
2. Augustus by Land and Sea (PIs VI-VII)48
“The sea figure is similarly unspecified; that is, she cannot be meant for Amphitrite or a particular sea goddess. She has two, long, fish-tail legs, one appearing in low relief between Augustus' legs, one partly cut off by the adjacent column. A skirt of large fish-fins conceals the transition to her cuirass-like torso. As often on sea-beings in human form, there are extra fish-fins on the shoulders. She has a late classical head and hairstyle and wears a thick wreath with a central medallion. She is handing the steering oar to Augustus. Her right arm, in low relief behind, disappears into uncarved stone beneath Augustus' drapery, while her left hand holds the lower end of the oar.”
The artist could’ve been inspired by Scylla statues, or by images of the Scythian ancestral goddess.
FWIW: The official website for the Aphrodisias Excavations identifies the emperor as Claudius, while the scholarly article identifies him as Augustus.
Smith, R. R. R. “The Imperial Reliefs from the Sebasteion at Aphrodisias.” Journal of Roman Studies, vol. 77, 1987, pp. 88–138.