 At the same occasion "Helix" is also a synonym of "Pomatia", but it is older and so it has precedence.At the species level, subjective synonyms are common because of an unexpectedly large range of variation in a species, or simple ignorance about an earlier description, may lead a biologist to describe a newly discovered specimen as a new species.A common reason for objective synonyms at this level is the creation of a replacement name.