Wastebasket taxon
Wastebasket taxon (also called a wastebin taxon,
The term was coined in a 1985 essay by
Examples
There are many examples of paraphyletic groups, but true "wastebasket" taxa are those that are known not to, and perhaps not intended to, represent natural groups, but are nevertheless used as convenient groups of organisms. The
- The Flacourtiaceae, a now-defunct family of flowering plants[7] – the Angiosperm Phylogeny Group has placed its tribes and genera in various other families, especially the Achariaceae and Salicaceae.
- The obsolete kingdom Protista is composed of all eukaryotes that are not animals, plants or fungi, leaving to the protists all single-celled eukaryotes.[8]
- The
- Carnosauria and Thecodontia are fossil groups, banded together back when the limited fossil record did not allow for a more detailed scheme.
- Meridiungulata or Protungulatum, may not represent laurasitherian mammals, while others like phenacodontids have been clearly established as early odd-toed ungulates.[10][11]
- The order Primates and sometimes grouped in Sundatheria, while tenrecs, golden moles and elephant shrews are all afrotheres, probably forming the clade Afroinsectiphilia. Both of these clades have at times been accused of being wastebasket taxa themselves, grouping superficially similar animals in Euarchonta and Afrotheria, respectively, but they have been more strongly supported by genetic studies.[citation needed]
- Vermes is an obsolete taxon of worm-like animals. It was a catch-all term used by Carl Linnaeus and Jean-Baptiste Lamarck for non-arthropod invertebrate animals.
- The genus Mamenchisaurus is sometimes considered a wastebasket taxon for large, long-necked dinosaurs.[12]
Wastebasket taxa in science
Fossil groups that are poorly known due to fragmentary remains are sometimes grouped together on gross morphology or stratigraphy, only later to be found to be wastebasket taxa, such as the crocodile-like Triassic group Rauisuchia.[13]
One of the roles of taxonomists is to identify wastebasket taxa and reclassify the content into more natural units. Sometimes, during taxonomic revisions, a wastebasket taxon can be salvaged after doing thorough research on its members, and then imposing tighter restrictions on what continues to be included. Such techniques "saved" Carnosauria and Megalosaurus. Other times, the taxonomic name contains too much unrelated "baggage" to be successfully salvaged. As such, it is usually dumped in favour of a new, more restrictive name (for example, Rhynchocephalia), or abandoned altogether (for example, Simia).[citation needed]
Related concepts
A related concept is that of
The term wastebasket taxon is sometimes employed in a derogatory fashion to refer to an evolutionary grade taxon.[citation needed]
See also
References
- PMID 20739322.
- ISBN 978-0-19-854916-1.
- .
- ^ Gould, S. J. (1985). "Treasures in a taxonomic wastebasket". Natural History. 94: 22–33.
- S2CID 86606882.
- S2CID 86606882.
- JSTOR 4110825.
- PMID 5762760.
- ^ Young AM (2002). "Brief notes on the status of Family Hygrophoraceae Lotsy". Australasian Mycologist. 21 (3): 114–6.
- ^ Naish, Darren (8 August 2013). "Phenacodontidae, I feel like I know you". Tetrapod Zoology. Scientific American.
- PMID 25295875.
- S2CID 219749618.
- PMID 14667392.