Fossilised Anzia (Lecanorales, lichen-forming Ascomycota) from European Tertiary amber

Abstract

Anzia electra sp. nov. is described and illustrated from Baltic amber dating back approx. 40 Myr. The diagnostic features of the fossilised species include the small, narrow lobed foliose thallus, two-layered medulla, lack of chondroidal axis, moniliform spongiostratum, and rhizines born singly at the margins of spongiostratum cushions. The fossil species demonstrates that all distinguishing features in the thallus morphology of Anzia sect. Anzia have remained stable for tens of millions of years. Hence the divergence of anzioid lichens must have occurred in the distant past, most probably before the Tertiary. The fossil also provides the first hard evidence that the disjunct-Laurasian distributions of some modern lichens represent relicts of a formerly wider range. The close similarity of the fossil to extant species in East Asia and eastern North America suggests that the present range of Anzia sect. Anzia is highly relict.