An Updated Review of the Middle‐Late Jurassic Yanliao Biota: Chronology, Taphonomy, Paleontology and Paleoecology

Abstract

The northeastern Chinese Yanliao Biota (sometimes called the Daohugou Biota) comprises numerous, frequently spectacular fossils of non‐marine organisms, occurring in Middle‐Upper Jurassic strata in western Liaoning, northern Hebei, and southeastern Inner Mongolia. The biota lasted for about 10 million years, divided into two phases: the Bathonian‐Callovian Daohugou phase (about 168–164 million years ago) and the Oxfordian Linglongta phase (164–159 million years ago). The Yanliao fossils are often taphonomically exceptional (many vertebrate skeletons, for example, are complete and accompanied by preserved integumentary features), and not only are taxonomically diverse but also include the oldest known representatives of many groups of plants, invertebrates, and vertebrates. These fossils have provided significant new information regarding the origins and early evolution of such clades as fleas, birds, and mammals, in addition to the evolution of some major biological structures such as feathers, and have demonstrated the existence of a complex terrestrial ecosystem in northeast China around the time of the Middle‐Late Jurassic boundary.

Palaeoenvironmental reconstruction and biostratinomic analysis of the Jurassic Yanliao Lagerstätte in northeastern China

“…The most obvious fold structures are synclines (and synforms) filled with Jurassic and Cretaceous strata; these are separated from anticlines with Precambrian rocks at the core by thrust and reverse faults that dip away from syncline hinges (Davis et al, 1998). The Yanliao Biota was discovered in the Jurassic Haifanggou and Tiaojishan formations (or Lanqi Formation in studies earlier than the 1990s) in three of these northeasttrending synclines (and synforms), belonging to the following basins: Lingyuan-Sanshijiazi (Wang et al, 1989;Wang et al, 2005;Sullivan et al, 2014;Huang, 2016;Xu et al, 2016).…”

“…Zhang, 2002) or part of the Yanliao Biota (e.g. Ren et al, 2002;Zhou et al, 2010;Xu et al, 2016). This paper follows the latter terminology, as the extent to which the term "Daohugou Biota" is applicable to the strata containing similar biotas outside the Daohugou region is currently debated (Zhou et al, 2010;Huang, 2016;Xu et al, 2016).…”

“…Ren et al, 2002;Zhou et al, 2010;Xu et al, 2016). This paper follows the latter terminology, as the extent to which the term "Daohugou Biota" is applicable to the strata containing similar biotas outside the Daohugou region is currently debated (Zhou et al, 2010;Huang, 2016;Xu et al, 2016). The Yanliao Biota spans about 10 million years, and is divided into two phases: the Bathonian-Callovian Daohugou phase and the Oxfordian Linglongta phase, named after representative fossil localities (Xu et al, 2016).…”

“…Despite extensive research on the biotic diversity and evolutionary significance of the Yanliao biota, the palaeoenvironmental setting is poorly understood (Wang et al, 2009;Wang et al, 2013;Na et al, 2015;Huang, 2016;Xu et al, 2016). It is widely accepted that the fossils are hosted within laminated lacustrine deposits.…”

A new skin-winged dinosaur from the Jurassic of northeast China

“…1) that sheds light on these questions, and corroborates the original interpretation of Yi as possessing a membranous flight apparatus. Like all other scansoriopterygids that have been discovered to date, the new specimen belongs to the Yanliao Biota, a diverse and increas-ingly well-known assemblage of fossil plants and animals dating to near the boundary between the Middle and Late Jurassic [6,7]. Like the Early Cretaceous Jehol Biota, the Yanliao Biota comes from the northeast Chinese lake deposits and is famous for preserving the delicate bones of small vertebrates, often accompanied by remnants of soft tissue such as feathers or hair.…”