Plant macrofossils from the Upper Cretaceous Nenjiang Formation in the Songliao Basin, NE China: Palaeoenvironmental implications

The lower Campanian members 2 and 3 of the Nenjiang Formation host a diverse array of cupressoid conifers (Glyptostrobus, Sequoiadendron, Cupressinocladus, Mesocyparis; commonly shoots and a few cones), a few unassigned conifers and putative ginkgophytes. True aquatics (Cobbania, Quereuxia) and water-bound plants (Nelumbites and Sparganiophyllum) have been recorded, as well as foliage and putative staminate flowers of the deciduous angiosperm tree Trochodendroides. The floral composition is very similar to assemblages from the adjacent Zeya-Bureya Basin (Far East Russia and Heijlongjiang, China), and it contains elements of contemporaneous floras from further away regions (Sakhalin, Honshu, Chukotka, Kamchatka), indicating an affiliation of the Nenjiang Flora to the Santonian–Campanian floras of north-east Asia and corroborating a Campanian age for the examined strata of the Nenjiang Formation. The flora thrived in and along the shores of a comparatively large lake that supported populations of three to four different species of free- or partly floating aquatics. •First description of plant macrofossils from the Nenjiang Formation, NE China.•Community includes conifers, true aquatics, water-bound plants and deciduous trees.•Floral composition is similar to assemblages from the adjacent Zeya-Bureya Basin.•Flora comparable with Campanian higher-latitude floras of NE Asia.•The flora thrived along the shores of a comparatively large lake.