The anatomy of most fish and reptiles is hardly suitable for dancing. Even Ronan has certain limitations, preferring head bobbing to flipper waving, for example, since the former is easier and allows for more flexibility.
Humans, though, aren't the only ones to use dancing in social situations to attract mates and admiration from onlookers.
Irena Schulz, director of the non-profit avian education organization Bird Lovers Only that houses Snowball, says that male cockatoos "display dance-like and other rhythmic behaviors to attract females." Some, for example, rhythmically sway, while others drum on tree branches with a stick to get a female’s attention.
Certain species are then naturally better at keeping a beat. Cook, Schulz and others are also trying to determine if a talent for vocal mimicry also predicts dancing ability, since both skills require matching incoming sound info with outgoing behaviors (vocalizing or grooving).
Sea lions, however, are not known to do vocal mimicry and have a limited repertoire of sounds, so it could be that a capacity for complex vocal learning is not necessary to boogie.
Yet another factor is the individual animal. Just as some people are better dancers than others, some particular animals are better beat-keepers than other members of their own species.
Musical tastes also come into play. Schulz said that she conducted musical therapy studies involving Snowball and an OCD cockatoo that used to pluck her feathers out. Schulz discovered that "the type of music that the OCD bird found to be calming was actually making Snowball more agitated/stir crazy. Likewise, the music that made the OCD parrot most agitated was the music that Snowball enjoyed most."
As she said, "What is good for the goose is not necessarily good for the gander."