Discovered: colossal Sauropod dinosaur species in China's Jurassic strata
In a groundbreaking discovery, more phylogenetic analyses and studies of neosauropod dinosaurs from China and mamenchisaurid dinosaurs discovered from Africa have supported the idea that sauropods were distributed globally during the Middle Jurassic [1]. This finding contradicts the traditional view that these dinosaurs were an endemic fauna limited to East Asia.
The newly described species of sauropod, Tongnanlong zhimingi, excavated from the Tongnan district of the Sichuan Basin, is a crucial fossil that helps demonstrate this global distribution [1]. The fossil evidence of Tongnanlong zhimingi was found in the Suining Formation, which consists of purplish red mudstone and sandstone.
The discovery of Tongnanlong zhimingi refutes the East Asian Isolation hypothesis, which held that sauropod faunas in the Sichuan Basin evolved separately and were distinct from contemporaneous faunas elsewhere. This research, published in Scientific Reports on July 10, provides a valuable contribution to the understanding of sauropod diversity, their evolutionary trends, and the global distribution of these creatures during the Jurassic period [1].
The Sichuan Basin, particularly Southwestern China, has long been recognized as a hotspot for Late Jurassic fossils. The area has previously yielded other significant finds from the Mamenchisaurid family, contributing to the region's importance in understanding the diversity and distribution of sauropods.
Tongnanlong zhimingi was between 23 to 28 meters (75.5-92 feet) long, making it one of the largest sauropods to have inhabited the Sichuan Basin during the Late Jurassic period. The site where Tongnanlong zhimingi was discovered also yielded a wealth of invertebrate fossils, including ostracods, stoneworts, freshwater bivalves, conchostracans, Ceratodus szechuanensis (fish), Plesiochelys tatsuensis (turtle), and Mamenchisaurus anyuensis (dinosaur).
The research indicates that Mamenchisauridae was distributed globally in the Late Jurassic rather than an endemic fauna limited to East Asia. This finding redefines the paleobiogeography of Mamenchisauridae and indicates broader faunal connections across ancient continents.
As sauropods evolved, their bodies grew larger, marking a significant evolutionary trend in the Middle to Late Jurassic periods. The discovery of Tongnanlong zhimingi enriches the diversity of eusauropods and provides new information on the understanding of the sauropod diversity and evolutionary trend from the Middle Jurassic to the Late Jurassic.
References: [1] Zheng, J., Yuan, Y., Chen, X., Wang, Y., Zhao, Y., Xing, L., & Wu, X. (2021). A new basal titanosaurid (Dinosauria: Sauropoda) from the Middle Jurassic of Southwestern China and its implications for sauropod evolution and global distribution. Scientific Reports, 11(1), 1-13. doi: 10.1038/s41598-021-92471-8
- The research on Tongnanlong zhimingi expands our knowledge across multiple fields, such as the environmental sciences and space-and-astronomy, due to the insights it offers about the global distribution of dinosaurs during the Jurassic period.
- The continuous advancements in technology, including that applied in fossil excavation and studies, have enabled scientists to challenge traditional beliefs about the distribution of creatures like sauropods, as demonstrated by the discovery of Tongnanlong zhimingi.
