sentences:  This shift possibly started as early as the Hellenistic Period, but is clearly evident in mermaid-like depictions of "sirens" in later Christian bestiaries.Some attributes of Homer's sirens, such as the enticement of men and their beautiful song, also became attached to the mermaid.There are also naturalist theories on the origins of the mermaid, postulating they derive from sightings of the manatee, or dugong or even seals.