Mamontov Y.S., J.Heinrichs, A.
Schäfer-Verwimp, M.S. Ignatov & E.E. Perkovsky. Hepatics from Rovno
amber (Ukraine), 2. Acrolejeunea ucrainica sp. nov.
Arctoa (2013) 22: 93-96
A fossil of Lejeuneaceae subfam. Ptychantoideae is described based on an
inclusion in Late Eocene Rovno amber. The unbranched sterile shoot has
obliquely spreading, squarrose, complicate-bilobed leaves with rounded lobes
and some dorsal lobe margins curved backwards as well as suberect upper shoot
sectors with small leaves possibly serving for vegetative distribution. Based
on morphological similarities the fossil is assigned to the extant genus Acrolejeunea,
as A. ucrainica Mamontov,
Heinrichs et Schaf.-Verw. sp. nov., being the first fossil of this genus
and the third liverwort from Rovno amber.