Paleobiota of the Yixian Formation
The Yixian Formation (simplified Chinese: 义县组; traditional Chinese: 義縣組; pinyin: Yìxiàn zǔ) is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans about 1.6 million years during the early Cretaceous period (Barremian-Aptian stage).
The Yixian Formation is divided into the following subunits: (ages from Zhong et al., 2021[1] unless otherwise noted) Dongbeititan D. dongi Partial postcrania[2] A basal titanosauriform cf.
Lujiatun & Jianshangou Beds Isolated vertebrae and teeth[7][4] One or more species of sauropods, possibly titanosaurs, have been recovered from the Yixian Formation, though most remain undescribed[3] The dinosaurs listed below were compiled in a survey by Xu and Norell in 2006, unless otherwise noted.
"[8] Liaoceratops L. yanzigouensis Beipiao Lujiatun Bed "[Two] nearly complete skulls, juvenile to adult.
"[17] A primitive short-tailed bird (pygostylian), also present in the Jiufotang Formation C. suniae Junior synonym of Confuciusornis sanctus[16] Dalingheornis D. liweii Dawangzhangzi Bed An Enantiornithine[19] Eoenantiornis E. buhleri Jianshangou Bed "Nearly complete skeleton.
[28] Liaoxiornis L. delicatus Dawangzhangzi Bed Considered a nomen dubium because the name is based on remains of a hatchling entantiornithine and cannot be confidently matched with the adult form.
[29] Lingyuanornis L. parvus Dawangzhangzi Bed Junior objective synonym of Liaoxiornis delicatus, a nomen dubium.
[32] Vescornis V. hebeiensis Previously regarded as Yixian, horizon reassigned to the Huajiying Formation by Jin et al., 2008.
A dromaeosaurid Zhongjianosaurus[41] Z. yangi Lingyuan A partial skeleton includes an arm, legs, vertebrae, ribs, and most of the tail.
"[45] A primitive ornithomimosaur Caudipteryx C. dongi Beipiao Jianshangou Bed "[One] partial postcranium with feather imprints.
[48] An oviraptorosaur Protarchaeopteryx P. robusta Beipiao Jianshangou Bed "Nearly complete skull and skeleton, at least [two] individuals.
"[49] A possible relative of Incisivosaurus Similicaudipteryx S. yixianensis Two specimens An oviraptorosaur, also present in the Jiufotang Formation[50] Xingtianosaurus X. ganqi Liaoning Dakangpu Bed One nearly complete specimen (IVPP V13390), minus the head An oviraptorosaur[51] Beipiaosaurus B. inexpectus Beipiao Jianshangou Bed "Incomplete skeleton with integument.
[61] Yutyrannus Y. huali Unknown Three nearly complete skeletons of various ages A large tyrannosauroid[62] Unnamed theropod Not yet described Yixian Lujiatun Bed Partial post-cranial skeleton[63] A possible carnosaur[64] The pterosaurs listed below were compiled in a survey by Wang and Zhou in 2006, unless otherwise noted.
[78] The arachnid species listed below follow a catalogue compiled by Dunlop, Penney and Jekel in 2010, unless otherwise noted.
The dragonfly species listed below follow a review compiled by Zhang, Ren and Panf in 2008, unless otherwise noted.
