Curiosities of Biological Nomenclature
Mark Isaak
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The Rules We Play By


Rules for assigning scientific names have become well codified in order to keep the names internationally unambiguous and understandable. The full set of rules is rather involved, but the most important parts are fairly simple:

Rules for Zoology

Bison (Bison) bison bison (Linne 1758) Skinner & Kaisen, 1947 (American bison)
Buettikoferella Stresemann 1928 (buff-banded grassbird) This name was originally published in an obituary. Stresemann mentioned, in an obituary for Buettikofer, that a bird genus was named after him, but Stresemann realized that Buettikoferia was preoccupied, so he proposed this as a replacement. [Orn. Monatsb. 36: 40,note4]
Megalochelys atlas (Rhodin et al. 2015) (giant Miocene-Pleistocene turtle) The fossil was first named Megalochelys sivalensis by Falconer & Cautley (1837), but that publication was a brief announcement with no description. They gave a complete description in 1844, but changed the name to Colossochelys atlas (because they felt that "Megalochelys" was not sufficiently expressive of the fossil's large size). A nomen nudum, or "naked name", i.e. a name without description, invalidates the species name but not, it turns out, names of genus or higher rank, so Megalochelys stayed, but sivalensis was replaced by atlas. (And Rhodin et al. get credit for first treating it under that combination [Turtles and Tortoises of the World during the Rise and Global Spread of Humanity].)
Nessiteras rhombopteryx (Loch Ness monster) This proposed name is not a valid scientific name because there is no type specimen to go with it.
Tanysiptera nympha G.R. Gray, 1840 (red-breasted paradise kingfisher) This name is accepted as valid even though underparts, wings, and rump of the mounted specimen Gray worked from came from at least three other species of birds, "artificially intermingled, to give the appearance of a perfect specimen." There was enough of the head and body to indicate a new species. [Dance, 1975, p. 77]
Cryptoclidus (plesiosaur from Oxford Clay) The spelling was intended to be Cryptocleidus (from the Greek for 'hidden clavicle'), but probably from a printing error, it appeared, and now remains, without the 'e'.
Eschscholzia Chamisso, 1820 (California poppy) Named for zoologist Johann Eschscholtz, but the 't' was omitted from the publication.
Haliaeetus Savigny 1809 (bald eagle) This name is a misspelling; the original description had an extra 'e', which must now stay there.
Huernia (African Asclepiadaceae) Named after Justus Heurnius, the first European to collect plants in South Africa, but the "eu" was transposed in publication.
Penstemon (flowering plant) The name derives from "five stamens", so some have called it Pentstemon or Pentastemon, but the shorter name has priority.
Wisteria Nuttall (woody vine) Named for Caspar Wistar, author of America's first anatomy textbook and successor of Thomas Jefferson as head of the American Philosophical Society. But Nuttall misspelled it with an "e", and the name is stuck.
Ambystoma or Amblystoma Tschudi 1838 (mole salamanders) Both names appeared in the original description. Amblystoma ("blunt mouth") was probably intended, but Ambystoma (and the family Ambystomatidae) is the accepted name now. Amblystoma is on the Official Index of Rejected and Invalid names, but it still gets quite a bit of use.
There are means of overruling priority, if the newer name has come into common use before the priority of the original name is recognized.
Scrotum humanum Brookes 1763 (Megalosaurus) Among the oldest dinosaur bones discovered. So named because the condyles had a testicular shape. Fortunately, the genus will continue to be known as Megalosaurus because that name came into common use before it was discovered that Scrotum was an earlier synonym. [Halstead & Sargent, 1993, Modern Geol. 18:221-4]
Sometimes the same name gets reused by people not aware of the original use:
Argus Bohadsch 1761 (gastropod)
Argus Scopoli 1763 (lycaenid)
Argus Scopoli 1777 (satyrid)
Argus Poli 1791 (mollusk)
Argus Temminck 1807 (bird)
Argus Lamarck 1817 (hesperiid)
Argus Boisduval 1832 (lycaenid)
Argus Walckenaer 1836 (arachnid)
Argus Gray 1847 (mollusk)
Argus Gerhard 1850 (lycaenid) Only the original name is valid. Since that name has priority, all the rest are junior homonyms and needed to be renamed.

However, the same name can be used for a plant and an animal. There are hundreds of instances. See hemihomonyms for the long list (though it includes invalid names). The samples given below are those I found before discovering that website.
Adonis L. 1753 (bird's-eye ranuncula) or Adonis Gronow 1854 (fish)
Ammophila (grass or sphecid wasp)
Andromeda L. 1753 (wild rosemary) or Andromeda Gistel 1834 (bupestrid beetle)
Appendicularia DC. (plant) or Appendicularia Fol, 1874 (free-swimming tunicate). It is also the name of the class which the latter is within.
Arenaria L. 1753 (Caryophyllaceae plant) or Arenaria Brisson 1760 (bird)
Aotus (pea or monkey)
Arctophila (grass or syrphid fly)
Aristotelia (tree or moth)
Bartramia (moss or sandpiper)
Bullockia (Rubiaceae or catfish)
Canarium (tropical tree or sea snail)
Cannabis L. (hemp) or Cannabis Blyth 1850 (bird)
Cecropia (tree or moth)
Cereus (cactus or sea anemone)
Chloris (grass or green finch)
Colocasia (taro or tussock moth)
Culcita (tree fern or echinoderm)
Cyanea (Hawaiian bellflower or jellyfish)
Dahlia Cav. (flower) or Dahlia Pagenstecher, 1900 (moth)
Darwinia Rudge 1815 (shrub) or Darwinia Pereyaslawzewa 1892 (flatworm)
Darwiniella Speg. 1888 (fungus) or Darwiniella Anderson 1992 (barnacle). There is also an illigimate name Darwiniella Braas & Luckel, 1982 (orchid)
Dionaea (venus flytrap) or Dionaea Robineau-Desvoidy, 1830 (fly)
Diphylleia Michx. 1803 (herbaceous plant) or Diphylleia Massart 1920 (protist)
Donax Lour. (arrowroot relative) or Donax L. (clam)
Dracunculus (herb or roundworm)
Drosophila (fungus, synonym of Typhrasa) or Drosophila (fruit fly)
Dryas (shrub or butterfly) The shrub gave its name to the Older and Younger Dryas geological periods.
Dugesia (composite or flatworm)
Eisenia (brown alga or earthworm)
Erica L. (heath) or Erica Peckham and Peckham 1892 (jumping spider)
Ficus (fig or gastropod)
Girardia S.F.Gray (red alga) or Girardia Ball, 1974 (flatworm)
Hamadryas (buttercup or butterfly)
Hymenolepis (yarrow relative or tapeworm)
Huberia DC. (Melatomataceae) or Huberia Forel, 1890 (ant)
Hystrix (grass or porcupine)
Iris (flower or mantis)
Knightia (Proteaceae plant or fossil fish)
Lactarius (fungus or fish)
Leptonia (toadstool (now usu. a subgenus of Entoloma) or rove beetle)
Lessonia (kelp or tyrant flycatcher)
Linaria Mill. (toadflax) or Linaria Bechstein 1802 (bird)
Liparis Rich. 1818 (orchid) or Liparis Scopoli 1777 (fish)
Lophophora J.M.Coult. (cactus) or Lophophora Möschler, 1890 (moth)
Lucilia Cass. (flower) or Lucilia Robineau-Desvoidy, 1830 (moth)
Mallotus Lour. (spurge) or Mallotus Cuvier, 1829 (fish)
Mauritia (palm or gastropod)
Megaceros (hornwort or Pleistocene deer)
Melanogaster Corda (false truffle) or Melanogaster Rondani, 1857 (hover fly)
Morus (mulberry or gannet)
Myrmecia (alga or ant)
Oenanthe (water celery or bird)
Perilla L. (mint) or Perilla Thorell, 1895 (spider)
Pieris (Japanese andromeda or butterfly)
Ponera Lindl. (orchid) or Ponera Latreille 1804 (ant)
Prosopis (mesquite or solitary bee)
Prunella Linnaeus 1753 (Lamiaceae plant) or Prunella Vieillot 1816 (bird)
Rhamphorhynchus (orchid or pterosaur)
Ricinus (castor bean or bird louse)
Sirindhornia (orchid or moth)
Sphaerostoma (fossil gymnosperm or trematode)
Stenella Syd. (1930) (fungus) or Stenella Gray 1866 (dolphin)
Trichia von Haller 1768 (slime mold) or Trichia Hartmann 1840 (snail)
Verticordia DC. (myrtle) or Verticordia Sowerby 1844) (clam)
Zenkerella (African legume or African rodent)
Zeus Minter & Diam. (1987) (fungus) or Zeus L. (dory)

There are even a few cases of duplicated binomials, where both genus and species get reused in different kingdoms:
Adesmia muricata (Linnaeus, 1758) (beetle) or Adesmia muricata (Jacq.) DC. (legume)
Agathis montana Shestakov, 1932 (wasp) or Agathis montana de Laub. (kauri, a conifer)
Asterina gibbosa (Pennant, 1777) (starfish) or Asterina gibbosa Gaillard (fungus)
Baileya australis (Grote, 1881) (moth) or Baileya australis Rydb. (desert marigold, synonym of B. multiradiata)
Centropogon australis (White, 1790) (waspfish) or Centropogon australis Gleason (bellflower)
Cuspidaria cuspidata (Olivi, 1792) (bivalve) or Cuspidaria cuspidata (M. Bieb.) Takht. (wallflower, a synonym of Erysimum cuspidatum)
Ficus variegata Röding, 1798 (sea snail) or Ficus variegata Blume (fig)
Gaussia princeps (T. Scott, 1894) (copepod) or Gaussia princeps H.Wendl. (palm)
Myrmecia pyriformis Smith, 1858 (ant) or Myrmecia pyriformis J.B.Petersen (green algae)
Orestias elegans Garman, 1895 (pupfish) or Orestias elegans Ridl. (orchid)
Thysanotus gracilis Jeannel, 1949 (ground beetle) or Thysanotus gracilis R.Br. (herb)
Tritonia pallida Stimpson, 1855 (nudibranch) or Tritonia pallida Ker Gawl. (iris)
Ekgmowechashala (early Miocene North American primate) The name means "small fox-man" in Lakota
Lainodon orueetxebarriai Gheerbrant & Astibia, 1994 (Upper Cretaceous mammal) The 'tx' is pronounced like English 'ch'.
Nqwebasaurus thwazi de Klerk et al. 2000 (Late Jurassic/Early Cretaceous South African coelurosaur) It is pronounced: N-(click with tongue)-KWE-bah-SAWR-us. If you are a real stickler for pronunciation, the "nq" is a nasal postalveolar click. Nqweba is the native Bantu name of the place where the dino was found.
Tahuantinsuyoa macantzatza Kullander 1986 (Peruvian cichlid) The genus is a Quechuan name of the Incan empire; this page has a pronunciation.

There are no official rules about how names should be pronounced. Still, many names have right and wrong pronunciations according to conventional usage.

Buddleja L. (shrub) Named after botanist and rector Adam Buddle in an era when 'j' sometimes signified a long 'i' between two vowels. It is pronounced BUD-ul-EYE-uh.
There are plenty of other rules; see the ICZN and specifically the International Code of Zoological Nomenclature for the complete set.

Rules for Botany

The rules above are for zoological nomenclature. The rules for botanical nomenclature are similar. Some exceptions are:

Taphrina cerasi (Fuck.) Sad. The fungus Taphrina cerasi was originally described by Karl Wilhelm Gottlieb Leopold Fuckel and later redescribed by Richard Emil Benjamin Sadebeck, so this listing now appears in some catalogs. The prefered citation, though, is Taphrina cerasi (Fuckel) Sadeb.
Ziziphus zizyphus (L.) H.Karst. (jujube)
Johnson-sea-linkia profunda N.J. Eiseman & S.A. Earle, 1983 (seaweed)

Rules for Fungi

Traditionally, fungi have been grouped with plants (even though, as later discovered, they are more closely related to animals). In 2011, this grouping was formalized, with the botanical code (ICBN) renamed the International Code of Nomenclature for algae, fungi, and plants (ICN).

Because fungi often have very different sexual and asexual forms, the same species of fungus could have two different scientific names, one for the sexual form and one for the asexual. This rule, however, has changed (with much gnashing of teeth) as of 2011, because DNA analysis makes it easier to recognize two forms as the same species.

Rules for Bacteria

There is also a separate International Code of Nomenclature of Prokaryotes governed by the International Committee on Systematics of Prokaryotes (ICSP). It has published the Approved Lists of Bacterial Names, listing all names valid as of 1 January 1980; it serves as a starting point for adding new names. "(Approved Lists 1980)" may be used in place of an author citation for names on the lists. Other rules particular to prokaryotes are:

Gordonia Stackebrandt et al. 1989 or Gordonia Newton, 1893 (Permian synapsid) or Gordonia J.Ellis (Theaceae)
Lawsonia McOrist et al. 1995 or Lawsonia Sharp, 1873 (beetle) or Lawsonia L. (Lythraceae)
Leptonema Hovind-Hougen 1983 or Leptonema Guérin, 1843 (caddisfly) or Leptonema A.Juss (Phyllanthaceae)
Moorella Collins et al. 1994 or Moorella Cameron, 1913 (parasitoid wasp) or Moorella P.Rag.Rao & D.Rao (saprophytic fungus)
Morganella Fulton, 1943 or Morganella Cockerell, 1897 (scale insect) or Morganella Zeller (1948) (puffball)
Rothia Georg and Brown 1967 or Rothia Westwood, 1877 (moth) or Rothia Pers. (legume)

See also Trüper 1999 in the references.

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