Fossil seeds of Euryale(Nymphaeaceae) indicate a lake or swamp environment in the late Miocene Zhaotong Basin of southwestern China

Euryale(Nymphaeaceae) is a monotypic genus distributed in eastern Asia, but fossils in its native distribution are sparse as compared to Europe where the genus has disappeared. Here, we describe a new fossil species, Euryale yunnanensis sp. nov., from the late Miocene Zhaotong Basin in southwestern China on the basis of seed remains. Characteristics including an ellipsoidal to almost spherical shape,a smooth surface, a germination cap that covers the micropyle, the separation of the hilum and germination cap(micropyle), elliptic testa surface cells with undulate margins and thickened cell walls collectively indicate a close affinity with the genus Euryale in Nymphaeaceae. Comparisons ofseed morphology and anatomy demonstrate that the newly described fossil species differs from modern and other fossil species of Euryale and thus verify the assignment to a new fossil species. As the modern Euryale is an aquatic plant,preferably living in swamps and lakes with shallow and stable water, we hypothesize that a lake and/or swamp environment with shallow water was present near Shuitangba in the Zhaotong Basin, where the Shuitangba hominoid lived during the late Miocene. This inference is generally consistent with paleoenvironmental data extracted from avian, fish, frog, turtle and crocodile fossils, as well as from aquatic pollen. The fossil history suggests a comparatively recent(Miocene) emergence of Euryale, which is roughly in agreement with the divergence time inferred from the molecular information.

Juvenile hominoid cranium from the terminal Miocene of Yunnan,China

Fossil apes are known from several late Miocene localities in Yunnan Province,southwestern China,principally from Shihuiba(Lufeng)and the Yuanmou Basin,and represent three species of Lufengpithecus.They mostly comprise large samples of isolated teeth,but there are also several partial or complete adult crania from Shihuiba and a single juvenile cranium from Yuanmou.Here we describe a new,relatively complete and largely undistorted juvenile cranium from the terminal Miocene locality of Shuitangba,also in Yunnan.It is only the second ape juvenile cranium recovered from the Miocene of Eurasia and it is provisionally assigned to the species present at Shihuiba,Lufengpithecus lufengensis.Lufengpithecus has most often been linked to the extant orangutan,Pongo pygmaeus,but recent studies of the crania from Shihuiba and Yuanmou have demonstrated that this is unlikely.The new cranium reinforces the view that Lufengpithecus represents a distinct,late surviving lineage of large apes in the late Miocene of East Asia that does not appear to be closely affiliated with any extant ape lineage.It substantially increases knowledge of cranial morphology in Lufengpithecus and demonstrates that species of this genus represent a morphologically diverse radiation of apes,which is consistent with the dynamic tectonic and biotic milieu of southwestern China in the late Miocene.