All organisms that have been studied must be given a scientific name, that is, a scientific name. Scientific names are established according to the International Code of Zoological or Botanical Nomenclature. Taxonomic units at all levels are represented by Latin or Latinized characters. The scientific name of the unit above the genus (each subgenus) is represented by a noun, that is, the mononomial method, in which the first letter is capitalized; the name of the species is represented by two words, that is, the binomial method, which is determined by the genus to which it belongs. The name (noun) plus the species name (adjective) can form a complete species name. The first letter of the species name should be lowercase, but the first letter of the genus name before the species name should still be capitalized. For the naming of subspecies, the three-digit method should be used, that is, after the genus and species names, plus the subspecies name (adjective), the first letter of the subspecies name should also be lowercase. When printing and writing, the names of units below the genus and genus are in italics, and the names above the genus are in regular font. A complete biological name should also include the namer's surname and the Gregorian calendar year when it was named, with the latter two separated by commas, such as Squamularia grandis Chao, 1929. Taking tigers as an example, its classification system and naming system are as follows:
Kingdom Animalia
Phylum Chordata Phylum Chordata
Subphylum Vertebrata Subphylum Vertebrata
Class Mammalia
Order Carnivora
Family Felidae
Genus Panthera
Panthera tigris tiger species
Some species can be divided into subspecies, and different populations have different traits due to geographical isolation to form geographical subspecies. In addition to geographical subspecies, there are also chronological subspecies in paleontology, that is, different populations within the same species that show different morphological characteristics at different times.
An important principle in the rules of biological nomenclature is the law of priority, that is, the effective scientific name of an organism is the earliest officially published name that complies with the international rules of animal or plant nomenclature. When the same organism has two or more names, it constitutes a synonym, or when different organisms have the same name, it constitutes a synonym. The earliest officially published name should be selected according to the law of precedence. For example, the brachiopod Cyrtospirifer was first named by Nalivkin in 1918. Later, Grabau named the same genus Sinospirifer in 1931. According to the law of precedence, the latter should be abandoned.
In fossil research, sometimes we encounter situations where the species cannot be accurately identified. In this case, special expressions must be used to indicate the species. The method of expression is usually to add some Latin abbreviations after the genus name:
1) sp. (abbreviation of species) is an undetermined species, which means that it is difficult to classify the specimen into a known species after identification, but it is unconditional Establish new species, such as Redlichia sp.
2) sp.indet. (species indeterminata, that is, species that cannot be identified) is an indeterminate species, which means that the fossils are poorly preserved and the species cannot be identified.
3) cf. (conformis, similar, comparable) is a similar species or a comparative species, which refers to a certain similarity in morphology with a known species, but there are still certain differences, such as Fusulina cf.cylindrica.
4) aff. (affinis, close) is a closely related species, indicating that the specimen has a certain genetic relationship with a known species, but there are differences in characteristics. Because the determination of genetic relationships between fossils is obviously artificial, paleontologists generally no longer use the aff. notation in recent years.
5) gen.nov. (genus novum, new genus) and sp.nov. (species novum, new species) are placed after the genus name and species name respectively, indicating that the name is proposed for the first time new genus name or new species name.
If the genus and species names are newly named, gen.et sp.nov. (genus et species novum) can be appended to indicate the new genus and species.