A possible brachiosaurid (Dinosauria, Sauropoda) from the mid-Cretaceous of northeastern China

Chun-Chi Liao; Andrew Moore; Changzhu Jin; Tzu-Ruei Yang; Masateru Shibata; Feng Jin; Bing Wang; Dongchun Jin; Yu Guo; Xing Xu

doi:10.7717/peerj.11957

A possible brachiosaurid (Dinosauria, Sauropoda) from the mid-Cretaceous of northeastern China

PeerJ. 2021 Aug 20:9:e11957. doi: 10.7717/peerj.11957. eCollection 2021.

Authors

Chun-Chi Liao^{1

2

3}, Andrew Moore⁴, Changzhu Jin^{1

2}, Tzu-Ruei Yang^{1

2}, Masateru Shibata^{5

6}, Feng Jin^{7

8

9}, Bing Wang^{7

8

9}, Dongchun Jin^{7

8

9}, Yu Guo¹⁰, Xing Xu^{1

2}

Affiliations

¹ Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Beijing, China.
² CAS Center for Excellence in Life and Paleoenvironment, Beijing, Beijing, China.
³ University of Chinese Academy of Sciences, Beijing, Beijing, China.
⁴ Department of Anatomical Sciences, Renaissance School of Medicine at Stony Brook University, NY, USA.
⁵ Fukui Prefectural Dinosaur Museum, Fukui, Japan.
⁶ Institute of Dinosaur Research, Fukui Prefectural University, Fukui, Japan.
⁷ Yanji Municipal Bureau of Land and Resources, Yanji, China.
⁸ Yanji Paleontological Research Centre, Yanji, China.
⁹ Yanji Dinosaur Museum, Yanji, China.
¹⁰ The Geological Museum of China, Beijing, Beijing, China.

Abstract

Brachiosauridae is a lineage of titanosauriform sauropods that includes some of the most iconic non-avian dinosaurs. Undisputed brachiosaurid fossils are known from the Late Jurassic through the Early Cretaceous of North America, Africa, and Europe, but proposed occurrences outside this range have proven controversial. Despite occasional suggestions that brachiosaurids dispersed into Asia, to date no fossils have provided convincing evidence for a pan-Laurasian distribution for the clade, and the failure to discover brachiosaurid fossils in the well-sampled sauropod-bearing horizons of the Early Cretaceous of Asia has been taken to evidence their genuine absence from the continent. Here we report on an isolated sauropod maxilla from the middle Cretaceous (Albian-Cenomanian) Longjing Formation of the Yanji basin of northeast China. Although the specimen preserves limited morphological information, it exhibits axially twisted dentition, a shared derived trait otherwise known only in brachiosaurids. Referral of the specimen to the Brachiosauridae receives support from phylogenetic analysis under both equal and implied weights parsimony, providing the most convincing evidence to date that brachiosaurids dispersed into Asia at some point in their evolutionary history. Inclusion in our phylogenetic analyses of an isolated sauropod dentary from the same site, for which an association with the maxilla is possible but uncertain, does not substantively alter these results. We consider several paleobiogeographic scenarios that could account for the occurrence of a middle Cretaceous Asian brachiosaurid, including dispersal from either North America or Europe during the Early Cretaceous. The identification of a brachiosaurid in the Longshan fauna, and the paleobiogeographic histories that could account for its presence there, are hypotheses that can be tested with continued study and excavation of fossils from the Longjing Formation.

Keywords: Albian-Cenomanian; Brachiosauridae; Cranial evolution; Early cretaceous; Longjing formation; Longshan fauna; Paleobiogeography.

Grants and funding

This work was supported by the National Natural Science Foundation of China (41688103), the Yanji Dinosaur Research Center, and a University of Chinese Academy of Sciences (UCAS) scholarship to Chun-Chi Liao. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.