Species or groups are put in the wastebsket taxon when they do not fit into one of the regular taxa. Regular taxa are supposed to be monophyletic. By definition, wastebasket taxa are either paraphyletic or polyphyletic. Their name may still be very useful to biologists, because its members may be an important evolutionary grade. Antelopes are a group which is ecologically very important, and have many similar features. However, they are not monophyletic. Species are called 'antelopes' if they look like one.
Invertebrates are often called the "everything-else" category, meaning all animals without backbones. Little-known fossil groups are sometimes later found to be wastebasket taxa. The crocodile-like Triassic group Rauisuchia is an example.
- or dustbin taxon or catch-all taxon
- Hallam A. & Wignall P.B. (1997). Mass extinctions and their aftermath. Oxford: Oxford University Press. p. 107. ISBN 978-0-19-854916-1.
- Monks N. (2002). "Cladistic analysis of a problematic ammonite group: the Hamitidae (Cretaceous, Albian-Turonian) and proposals for new cladistic terms". Palaeontology 45 (4): 689–707. doi:10.1111/1475-4983.00255.
- Nesbitt, S. J. (2003). "Arizonasaurus and its implications for archosaur divergence". Proceedings of the Royal Society B 270 (Suppl. 2): S234–S237. doi:10.1098/rsbl.2003.0066. Full free text.