A thalloid organism with possible lichen affinity from the Jurassic of northeastern China

Documentation of fossil lichens is rare, despite the fact that lichenization in fungi is believed to be ancient and many paleoecosystems should have provided ample suitable habitats for these organisms. Impression fossils of a cm-sized thalloid organism, Daohugouthallus ciliiferus nov. gen. et spec., are described from a Middle Jurassic deposit nearby Daohugou village, Inner Mongolia, China. The thallus comprises elongate primary axes from which extend lateral and terminal branches that fork once to repeatedly. Extending from all branches (mostly from the lateral margins and tips) are filiform appendages that closely resemble the cilia of certain extant lichens. Some branch tips appear ruptured and covered by minute irregularities, and appear similar to lichen soralia. One specimen is associated with a small seed cone and suggestive of epiphytic growth. The structural similarities with extant lichens, close association with land plants, and the environment in which the organism lived, suggest that the affinity of D. ciliiferus is with the lichens.