A new thalloid liverwort: Pallaviciniites sandaolingensis sp. nov. from the Middle Jurassic of Turpan–Hami Basin, NW China

Abstract

Here we described a fossil thalloid liverwort from the Middle Jurassic Xishanyao Formation, Turpan–Hami Basin, China, preserved as a carbonized compression in greyish-green siltstones. The fossil thalloid liverwort is characterized by the long and strap-like thallus with a well-defined costa, entire margins and polygonal cells in the thallus wings. Following comparisons of the present fossil with extant and other related fossil liverworts, a new species, Pallaviciniites sandaolingensis sp. nov., is established in the subclass Pallaviciniineae, Pallaviciniales of the new classification system. It is probable that Pallaviciniites sandaolingensis grew on moist soils and rock surfaces near lakes and rivers in a humid and warm environment.