Where: Hebei, China (41.2° N, 118.0° E: paleocoordinates 43.3° N, 120.1° E)
• coordinate based on nearby landmark
• outcrop-level geographic resolution
When: Yixian Formation (Jehol Group), Late/Upper Barremian (130.0 - 125.5 Ma)
• The Yixian Formation can be subdivided into five units, in ascending order, Lujiatun unit, Lower Lava, Jianshangou unit, Upper Lava, Dawangzhangzi unit, Jingangshan unit, and Huanghuashan unit. Most of the Jehol fossils from the Yixian Formation are preserved in four beds, that is, the Lujiatun bed (recalculated age is 124.0 ± 1.0/1.3 Ma, He et al., 2006), the Jianshangou bed (125.43 ± 0.50/0.88 Ma, Swisher et al., 1999), the Dawangzhangzi bed, and Jinggangshan bed (~122 Ma, Smith et al., 1995).U-Pb dating suggests that the Huangbanjigou section ranges from 124.9 ± 1.7 Ma to 122.8 ± 1.6 Ma (Yang et al., 2007). Chang et al. (2017) obtained Ar/Ar ages of 125.8 ± 1.0 Ma and 126.0 ± 0.8 Ma from the Lujiatun Unit, the lowest part of the Yixian Formation, below the lacustrine shales.
•He et al. (2004) reported a 40Ar/39Ar age of 120.3 ± 0.7 Ma for a tuff layer in the lower part of the Jiufotang Formation, and Chang et al. (2009) obtained a 40Ar/39Ar age of 122.1 ± 0.3 Ma for a tuff layer from the lowermost part of the Jiufotang Formation. Yu et al. (2021) dated an ash bed just above the Yixian/Jiufotang formation boundary to 122.0 ± 0.9 Ma and three tuff beds from the Xiaotaizi section to 118.9 ± 0.8 Ma, 118.8 ± 0.6 Ma, and 118.6 ± 1.1 Ma. These ages suggest that the Jiufotang Formation in Jianchang Basin was deposited at ca. 122.0–118.9 Ma.
•Olierrok et al. (2019) used a selection of U-Pb and 40Ar-39Ar geochronology to place the Barremian–Aptian boundary (the base of the Chron M0r) between 123.8 and 121.8 Ma. The GTS 2020 uses an age of 121.4 Ma for the base of the Aptian, and multiproxy orbital tuning gives an age of 120.2 Ma for the Barremian-Aptian boundary (Leandro et al., 2022). Therefore, the Yixian Formation should be entirely Late Barremian, with the Jiufotang Formation deposited in the Early Aptian (or latest Barremian at its base).
• group of beds-level stratigraphic resolution
Environment/lithology: lacustrine - large; lithified mudstone
Size class: mesofossils
Preservation: mold/impression
Primary reference: D. Ren. 1995. Insecta. In D. Ren, L.W. Lu, Z.G. Guo, S.A. Ji (eds.), Faunae and stratigraphy of Jurassic-Cretaceous in Beijing and the adjacent areas 47-121 [M. Clapham/M. Clapham]more details
Purpose of describing collection: taxonomic analysis
PaleoDB collection 107001: authorized by Matthew Clapham, entered by Matthew Clapham on 31.03.2011
Creative Commons license: CC BY (attribution)
Taxonomic list
Insecta | |
"Liadoxyela chengdeensis n. sp." = Angaridyela chengdeensis
"Liadoxyela chengdeensis n. sp." = Angaridyela chengdeensis Ren 1995 sawfly | |
Sinosepulca gigathoracalis n. gen. n. sp.
Sinosepulca gigathoracalis n. gen. n. sp. Ren 1995 sawfly | |
Allogaster ovata n. gen. n. sp.
Allogaster ovata n. gen. n. sp. Ren 1995 wasp | |
Baissodes grabaui n. sp.
Baissodes grabaui n. sp. Ren 1995 apoid wasp | |
Jeholoropronia pingi n. gen. n. sp.
Jeholoropronia pingi n. gen. n. sp. Ren 1995 wasp | |
Chengdeserphus petiolatus n. gen. n. sp.
Chengdeserphus petiolatus n. gen. n. sp. Ren 1995 wasp | |
Manlaya flexuosa n. sp.
Manlaya flexuosa n. sp. Ren 1995 wasp | |
Scolichneumon rectivenius n. gen. n. sp., Yanocleistogaster canaliculata n. gen. n. sp., Mesaulacinus rasnitsyni n. sp.
Scolichneumon rectivenius n. gen. n. sp. Ren 1995 wasp
Yanocleistogaster canaliculata n. gen. n. sp. Ren 1995 wasp
Mesaulacinus rasnitsyni n. sp. Ren 1995 wasp | |
Multimodus dissitus n. sp. Ren 1995 caddisfly
? Multimodus elongatus n. sp. Ren 1995 caddisfly
Multimodus stigmaeus n. sp. Ren 1995 caddisfly | |
"Yanorthophlebia hebeiensis n. gen. n. sp." = Liassochorista hebeiensis
"Yanorthophlebia hebeiensis n. gen. n. sp." = Liassochorista hebeiensis Ren 1995 scorpionfly | |
Yanoraphidia gaoi n. gen. n. sp.
Yanoraphidia gaoi n. gen. n. sp. Ren 1995 snakefly | |
Yanosmylus rarivenatus n. gen. n. sp.
Yanosmylus rarivenatus n. gen. n. sp. Ren 1995 lacewing | |
Sinoviparosiphum lini n. gen. n. sp.
Sinoviparosiphum lini n. gen. n. sp. Ren 1995 aphid | |
Yanocossus guoi n. gen. n. sp.
Yanocossus guoi n. gen. n. sp. Ren 1995 true bug | |
"Habrohagla curtivenata n. gen. n. sp." = Parahagla sibirica
"Habrohagla curtivenata n. gen. n. sp." = Parahagla sibirica Sharov 1968 hump-winged cricket | |
Sinohagla pleioneura n. sp.
Sinohagla pleioneura n. sp. Ren 1995 hump-winged cricket | |
"Blattula extenuata n. sp." = Elisama extenuata, Blattula delicatula n. sp., Blattula platypa n. sp.
"Blattula extenuata n. sp." = Elisama extenuata Ren 1995 cockroach
Blattula delicatula n. sp. Ren 1995 cockroach
Blattula platypa n. sp. Ren 1995 cockroach | |
Basilorhagio venustus n. gen. n. sp.
Basilorhagio venustus n. gen. n. sp. Ren 1995 dagger fly | |
Opiparifungivora aliena n. gen. n. sp.
Opiparifungivora aliena n. gen. n. sp. Ren 1995 fly | |
Atalosciophila yanensis n. gen. n. sp.
Atalosciophila yanensis n. gen. n. sp. Ren 1995 fungus gnat | |
Lichnoplecia kovalevi n. gen. n. sp.
Lichnoplecia kovalevi n. gen. n. sp. Ren 1995 march fly |