A pantropical ("all tropics") distribution is one which covers tropical regions of both the Eastern and Western hemispheres.[1] Examples of species include caecilians, modern sirenians and the plant genera Acacia and Bacopa.[2]
Neotropical is a zoogeographic term that covers a large part of the Americas, roughly from Mexico and the Caribbean southwards (including cold regions in southernmost South America).
Palaeotropical refers to geographical occurrence. For a distribution to be palaeotropical a taxon must occur in tropical regions in the Old World.
According to Takhtajan (1978), the following families have a pantropical distribution: Annonaceae, Hernandiaceae, Lauraceae, Piperaceae, Urticaceae, Dilleniaceae, Tetrameristaceae, Passifloraceae, Bombacaceae, Euphorbiaceae, Rhizophoraceae, Myrtaceae, Anacardiaceae, Sapindaceae, Malpighiaceae, Proteaceae, Bignoniaceae, Orchidaceae and Arecaceae.[3][4]