Epitype

It is clear, therefore, where any epitype, selected as an interpretive type, should be sought. The selection of an epitype, in the absence of type or authentic material, would be important, for any further molecular work will need to have available a culture of the type species of the genus which has some nomenclatural standing, i.e. a culture derived from the epitype.

Source: wiktionary

The epitype does not displace the primary type it is to interpret, but rather supplements it.

Source: wiktionary

In cases where a name-bearing type exists but does not show features needed for conclusive identification with a particular species circumscription, for example, one lacking spores, an interpretative type, an epitype, can be designated to supplement information evident in the name-bearing type. Epitypes are increasingly being designated in mycology today for sequenced material where DNA has not or cannot be recovered from the name-bearing type.

Source: wiktionary

To test this hypothesis our discussion is focused on finding evidence for gene-specific epitypes that supports or rejects cause-and-effect relationships between genotype, epitype and phenotype.[…]The first approach (A) examines the penetrance of transgenerationally inherited epitypes that are known to activate or silence the expression of disease related gene(s), which in turn correlate with onset of the "aberrant" disease phenotypes.[…]The second and less direct approach (B) searches out epitypes that are duplicated, as DNA sequences are duplicated, and examines multiple copies of DNA sequence and epitype that have been evolutionarily co-conserved.

Source: wiktionary