More on Erinaceus europaeus here.

From wikipedia:

“When a creature is discovered, it is first necessary to determine whether it is a new species, a new subspecies or merely a variant of an already described and known species. As there is no single, unambiguous definition of “species” this determination can be time-consuming and subject to discussion and disagreement.

By tradition, the right to name a new species is given to the discoverer, or more precisely the scientific describer of the species (who is not necessarily the person who discovered the species in nature). There are, however, many regulations to be followed when naming a species, all of them fixed by the International Code of Zoological Nomenclature (ICZN) when animals are concerned, or the International Code of Botanical Nomenclature (ICBN) for plants.

In general, the nomenclature of creatures follows a system established 1758 by Carl von Linné and each scientific species name is a composite of two parts, namely the genus name and the species name. For example, the scientific name of the European Common Frog is Rana temporaria, where Rana is the genus name and temporaria is the species name.

As the genus name should reflect relationships among different species within the same genus, the first attempt after each discovery is to allocate the creature to a respective genus (and the systematic categories of higher hierarchical levels). Thus in most cases, with exception of the discovery of new genera, the genus name is fixed already, whereas the species name may be freely chosen by the scientic describer of the species within the frame of the ICZN or ICBN regulations.”

Via IFLS