The lowermost Upper Devonian fossil Pallaviciniites was for a time the oldest known liverwort until Metzgeriothallus was recovered from earlier Devonian strata.[2]
It had a central axis, and bifurcated at its tips; similar fossils have been found in younger strata through to the Pleistocene.[3] With the exception of its elongated axial conducting (non-vascular) cells, the thallus was a single cell thick.[4] It had a serrated margin.[1]
Prior to its discovery, the oldest known liverworts dated to the Lower Carboniferous.[3]
References
^ abHueber, F. M. (1961). "Hepaticites devonicus, a New Fossil Liverwort from the Devonian of New York". Annals of the Missouri Botanical Garden. 48 (2): 125–131. doi:10.2307/2394879. JSTOR2394879.
^Hernick, L.; Landing, E.; Bartowski, K. (2008). "Earth's oldest liverworts—Metzgeriothallus sharonae sp. Nov. From the Middle Devonian (Givetian) of eastern New York, USA". Review of Palaeobotany and Palynology. 148 (2–4): 154–162. Bibcode:2008RPaPa.148..154H. doi:10.1016/j.revpalbo.2007.09.002.