Dear Maurizio,

the "sibling species" is a concept that applies to species that are closely
related and show little or no "evident" morphological differences (see e.g.
Mayr's books). It is commonly used referring to two different things:
- sister species: the two daugthers of an ancestral mother-species (thus
they're actually "sibling"). Often in this case the morphological
differences between the two sister species are weak but this is not an
universal rule.
- cryptic species: they are species nearly indistiguishable from
morphology. Since "cryptic" is a word that is used in ecology with respect
to mimetic patterns, this is a concept that has been little used in this
other context.

>B) When two new genera are introduced ans subsequently regarded as
synonyms, the priority goes to the one first described, regardless the type
species.
Thus Oliva Bruguiere, 1789 has precedence over Porphyria Roding, 1798.


=========================================================
Marco Oliverio - Evolutionary Biology PhD
Research Scientist

Dipartimento di Biologia Animale e dell'Uomo
Viale dell'Universita' 32
I-00185 Roma   ITALY

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