Ignatov,
M.S. & E.E. Perkovsky. Mosses from Rovno amber (Ukraine)
Arctoa (2011) 20: 1-18
Four moss genera are revealed in the Lower
Triassic deposits of Yaman Us (Mongolia). One of them, Tricostium, was formerly described from the Upper Jurassic. Three genera,
Yamanusia, Atrichites and Palaeosyrrhopodon, are
described as a new for science. All these four genera are
represented in collection by leaves with finely preserved laminal cell
structure. The strong costa and relatively short lamial cells indicate their
position within acrocarpous mosses.