Ontogeny

Age differences in Behavior

With age and size come differences in the use of aquatic bipedal behavior in basilisks. The older lizards are more likely to abandon bipedal behavior and swim through the water instead. In general, lighter lizards are able to keep a greater portion of their body out of the water, allowing for more efficient motion across it. Heavier, and typically older, basilisks can swim through the water faster than they can run through it. According to Joshua Laerm, "[t]he ratio of the weight to surface area provided by the feet is probably the most limiting factor involved in aquatic bipedalism, the expectation being that very young or small bipedal lizards would be able to provide greater drag forces propotional to their body weight." It is more effective for the younger lizards to move bipedally through water because they can do so more quickly than they can swim. In older lizards, however, the opposite is true.