Where: Nei Mongol, China (41.3° N, 119.2° E: paleocoordinates 43.0° N, 123.1° E)

• coordinate stated in text

• outcrop-level geographic resolution

When: Tiaojishan Formation, Early/Lower Callovian (164.7 - 161.2 Ma)

• Zhou et al (2013): "The Daohugou site in the Tiaojishan Formation of Inner Mongolia, China; the locality was directly dated to be 165–164 million years (Myr) old".

•

•Older information: "possible dates [range] from Middle Jurassic to Early Cretaceous. However, published radioisotopic [both 40Ar/39Ar and zircon U-Pb] dating results span... 152 to 168 Myr" = Bathonian to Kimmeridgian (Zhang et al. 2008). Also referred to as Haifanggou Formation

•

•"Several recent isotope datings, using both 40 Ar/39Ar and SHRIMP U-Pb methods, have indicated that the age of the (underlying) ignimbrite is between the late Middle Jurassic and early Late Jurassic, or 159-164 Ma. Therefore, the Daohugou Bed cannot be older than this age, and is not comparable to the Middle Jurassic Jiulongshan Formation" (Wang et al. 2005). Unit is older than overlying Yixian Formation. Age is therefore constrained to Callovian-Barremian

•

• formation-level stratigraphic resolution

Environment/lithology: lacustrine - large; lithified shale and tuff

Size classes: macrofossils, mesofossils

Preservation: mold/impression, adpression, soft parts, original phosphate

Reposited in the IVPP

Collection methods: bulk, quarrying, mechanical,

• IVPP and NIGP collections

Primary reference: C.-F. Zhou, S. Wu, T. Martin and Z.-X. Luo. 2013. A Jurassic mammaliaform and the earliest mammalian evolutionary adaptations. Nature 500:163-167 [P. Mannion/P. Mannion/P. Mannion]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 27891: authorized by Matthew Carrano, entered by Matthew Carrano on 15.01.2003, edited by Kaitlin Maguire, Mark Uhen, Matthew Clapham, John Alroy, Richard Butler, Roger Benson, Philip Mannion and Jonathan Tennant

Creative Commons license: CC BY (attribution)