中国科学院南京地质古生物研究所机构知识库

A new liverwort with perichaetium and perigonium collected from the Middle Jurassic Yima Formation is described. Gametophyte is dorsivental, irregularly branched, bearing two-ranks of lateral leaves obliquely attached to main axis, and one rank of ventral leaves transversely attached to ventral surface of the axis. Lateral branch bearing perigonium arises from axil of ventral leaves. Perigonium consists of small paired perigonial bracts arranged in a spike. Two perichaetia are borne on the top of lateral branches with an ovate perianth bearing longitudinal ridges and grooves. Setae are thin and straight and stretch out from the aristulate perianth mouth. General morphology of this fossil bears resemblance to some living liverworts of Jungermanniales. It is so far the oldest fossil record of Jungermanniales in the world.