⁴⁰Ar/³⁹Ar dating of ignimbrite from Inner Mongolia, northeastern China, indicates a post‐Middle Jurassic age for the overlying Daohugou Bed

Abstract

The 40Ar/39Ar step heating analyses of K‐feldspar derived from the ignimbrite in Inner Mongolia, China indicates that they were formed at 159.8 ± 0.8 Ma, which provides a maximum age for the overlying fossil‐bearing lacustrine deposits (Daohugou Bed). This result favors a post‐Middle Jurassic (Late Jurassic or younger), rather than the Middle Jurassic age for the Daohugou Bed. Such a result is generally consistent with vertebrate biostratigraphic evidence, providing a maximum known age for the first appearance of several major animal groups such as Cryptobranchidae of Urodela (salamanders) and Maniraptora (birds and their closest dinosaurian relatives).

Constraints on the upper boundary age of the Tiaojishan Formation volcanic rocks in West Liaoning-North Hebei by LA-ICP-MS dating

“…In the Daohugou area, a lot of isotopic ages of the Tiaojishan Formation have been obtained by the previous researchers [6,9,19,29] (Figure 3), and the data are from 170 to 152 Ma, but mostly between 166 and 157 Ma ( Figure 3).…”

New long-tailed pterosaurs (Wukongopteridae) from western Liaoning, China

“…This is due to several discoveries from the so called Jehol Biota (e.g., Chang et al 2003). Pterosaur specimens were collected mainly in the Early Cretaceous Yixian and Jiufotang Formations (e.g., He et al 2004), where 13 and 16 species were recognized, respectively (e.g., , 2008, Lü et al 2008, Andres and Ji 2008, Lü 2010, some of which have spurred controversy (e.g., Ji et al 1999, Unwin et al 2000, Wang and Zhou 2006, Lü et al 2006). …”

“…The stratigraphy of these deposits is disputed, with some regarding them as part of the Daohugou Formation (e.g., Wang et al 2009), whereas others refer them to the Tiaojishan Formation (e.g., Lü et al 2010). There are also questions about the age of these deposits, ranging from Middle to Late Jurassic (Zhang 2002 up to the Early Cretaceous (e.g., , He et al 2004). …”

On the identification of feather structures in stem-line representatives of birds: evidence from fossils and actuopalaeontology

“…The general taphonomic history links preservation of these biotas to episodes of volcanic activity (Zhou et al 2003;He et al 2004;Benton et al 2008). The sediments represent freshwater lacustrine environments (Zhou et al 2003;He et al 2004;Hu et al 2009).…”

“…The general taphonomic history links preservation of these biotas to episodes of volcanic activity (Zhou et al 2003;He et al 2004;Benton et al 2008). The sediments represent freshwater lacustrine environments (Zhou et al 2003;He et al 2004;Hu et al 2009). Freshwater and terrestrial organisms from these biotas that usually occur together within the same sedimentary horizon were presumably buried rapidly in the fine-grained sediments produced by catastrophic events (Zhou et al 2003;Benton et al 2008).…”