Species
Basic unit of taxonomic classification, below genus
A species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. It can be 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, palaeontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. About 14% of these had been described by 2011. All species are given a two-part binomial name. The first part is the name of the genus to which the species belongs. The second part is called the specific name or the specific epithet. For example, Boa constrictor is one of the species of the genus Boa, with constrictor being the specific name.
“Species” enters the record as basic unit of taxonomic classification, below genus. Crown Archives preserves that source wording while asking what Species, Basic and unit can confirm, complicate or overturn.
Why this record matters
“Species” is worth following because a concise public description often conceals a longer documentary argument. Here, Species, Basic and unit provides the most credible route into that argument.
Datasets, specimens, observations and peer-reviewed methods provide the appropriate test for the technical claims summarized here. The source revision retrieved here is dated Sep 10, 2026. The first chronological checks are 2011.
Current terminology should not be projected backward without checking the classification used when the underlying evidence was created. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Check terminology, classification and the date of the cited evidence. Scientific names and technical consensus can change while older records retain historical value.
- Current terminology
- Classification context
- Finding cited technical literature
Primary datasets, specimen catalogues, standards bodies and the most recent peer-reviewed literature.
Three-step research path
- Establish the record: confirm the title “Species”, its source revision and the description used here.
- Expand the search: follow Species primary sources, Species archive and Species research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Species”?
- Has classification or technical consensus changed since the cited source?
- Which observation, specimen, dataset or publication supports the account?
Search terms from this dossier
This entry incorporates text from “Species” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.