Pantropical
A pantropical distribution is one which covers tropical regions of both hemispheres. Examples include caecilians, modern sirenians and the plant genera Acacia and Bacopa.
Neotropical is a zoogeographic term that covers a large part of the Americas, roughly from Mexico and the Caribbean southwards.
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, 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.