| Guildfordia hendersoni | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| Clade: | Vetigastropoda |
| Order: | Trochida |
| Superfamily: | Trochoidea |
| Family: | Turbinidae |
| Genus: | Guildfordia |
| Species: | †G. hendersoni |
| Binomial name | |
| †Guildfordia hendersoni (Marwick, 1934) | |
| Synonyms [1] | |
Guildfordia (Opella) hendersoni(Marwick, 1934) | |
Guildfordia hendersoni is an extinct species of sea snail, a marine gastropod mollusk, in the family Turbinidae, the turban snails. [1]
In biology, a species (, is the basic unit of classification and a taxonomic rank, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. But these are not entirely satisfactory definitions. Scientists and conservationists need a species definition which allows them to work, regardless of the theoretical difficulties. If, as Carl Linnaeus thought, species were fixed and clearly distinct from one another, there would be no problem, but evolutionary processes cause species to change continually, and to grade into one another. While these definitions are often adequate, when looked at more closely they are problematic. For example, the boundaries between closely related species become unclear with hybridisation, in a species complex of hundreds of similar microspecies, and in a ring species. Also, among organisms that reproduce only asexually, the concept of a reproductive species breaks down, and each clone is potentially a microspecies.
Sea snail is a common name for snails that normally live in saltwater, in other words marine gastropods. The taxonomic class Gastropoda also includes snails that live in other habitats, such as land snails and freshwater snails. Many species of sea snails are edible and exploited as food sources by humans.
Family is one of the eight major hierarcical taxonomic ranks in Linnaean taxonomy; it is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as being the "walnut family".
