A new Cretaceous record of Platanoxylon (Platanaceae): the first Mesozoic angiosperm wood from China.

A new record of Cretaceous platanaceous wood, Platanoxylon sp., is described from Keshan, Heilongjiang Province, Northeast China. The features indicating it belongs to Platanoxylon include: growth rings distinct, wood diffuse-porous, vessels numerous, solitary and in short radial or tangential multiples, perforation plates exclusively scalariform, intervessel pits opposite, elliptical, horizontally elongated, vessel-ray pits similar to intervessel pits, some fibers with distinctly bordered pits, axial parenchyma diffuse, rays mostly large homocellular multiseriate, rarely uniseriate, and crystals often in ray cells. Fossil platanaceous woods are common in the Northern Hemisphere. Yet, Platanoxylon sp. is China's first report of fossil Platanaceae wood. It is also China's first record of Cretaceous angiosperm wood. This wood and compression floras indicate that the Platanaceae were in northern China from the Late Cretaceous to the Eocene. [ABSTRACT FROM AUTHOR]