Scientists have recovered a 120-million-year-old dinosaur fossil from a depth of 473.2 meters inside a mineral exploration drill core in northern China’s Inner Mongolia Autonomous Region. The rare specimen, which dates to the Early Cretaceous epoch, marks the first dinosaur discovery in the western Yin’gen-Ejinaqi Basin.
Guaizihu
Most prehistoric discoveries begin with shovels, pickaxes, and careful hand-scraping beneath open skies. But a team of Chinese geologists searching for copper mineral deposits near the settlement of Guaizihu stumbled upon something far older by accident.
Cataloged as 208GPV01, the fossilized remains were hauled up from a drill core at a depth of 473.2 meters, roughly 1,500 feet below the surface. The find emerged from the upper part of the Bayan Gobi Formation, a continental rock unit dating back to the Early Cretaceous. Researchers published their findings online in the journal Earth History and Biodiversity. A research team of members from the nuclear industry and paleontology research institutions published the finding online Thursday in the journal Earth History and Biodiversity. According to the study, the dinosaur bones were found 473.2 meters down in a drill core in 2023. They were preserved in the upper part of the Bayan Gobi Formation, a geological layer of ancient sediment dating to the Early Cretaceous, about 120 million years ago.
An Accidental Find in an Uncharted Basin
Yin’gen-Ejinaqi Basin
The scientific value of the specimen lies as much in its geographic position as in its anatomy. While the Bayan Gobi Formation has long served as a productive hunting ground for prehistoric remains, nearly all prior discoveries clustered in the eastern reaches of the Yin’gen-Ejinaqi Basin. This recovery marks the first published dinosaur record from the western section of the basin.
The discovery fills a major geographic gap in northern China’s fossil record. According to researchers, the local fauna shares notable similarities with contemporaneous deposits in Western Liaoning, suggesting both regions fall within the radiation range of the Jehol Biota. The Bayan Gobi Formation is an Early Cretaceous continental deposit in northern China, primarily exposed within the Yin’gen-Ejinaqi Basin of western Inner Mongolia,
said Dr. Lida Xing, a researcher at the China University of Geosciences and the Dinosaur Odyssey Science Museum, and colleagues. Its fauna shares similarities with that of the nearly contemporaneous Western Liaoning, suggesting that both may belong to the radiation range of the Jehol Biota, although some differences exist.
The 208GPV01 fossil dates back roughly 115 million years to the Early Cretaceous epoch. It consists mainly of proximal tail vertebrae along with several associated elements. 208GPV01 comprises a sacral rib, four caudal vertebral centra, six caudal neural arches, several transverse processes, and ossified tendons,
the researchers said.
As the first dinosaur fossil record from the western Yingen-Ejinaqi Basin, the new find fills a gap and opens new prospects for future prehistoric vertebrate exploration in western Inner Mongolia,
Chinese paleontologist Xing Lida told the Global Times.
Snorre oil field
Dinosaur fossils extracted from industrial drilling cores remain exceptionally rare worldwide. Dinosaur fossils found in drill cores are extremely rare worldwide, said co-author Xing Lida, a dinosaur expert from China University of Geosciences (Beijing). Paleontologists point to a famous 1997 precedent at the Snorre oil field in the northern North Sea, where an exploration well struck a crushed limb bone 2,256 meters below the seabed. One of the most famous cases occurred in 1997, when an exploration well at the Snorre oil field in the northern North Sea struck a crushed limb bone in a drill core about 2,256 meters below the seabed. Scientists later identified it as a plant-eating dinosaur. The discovery showed that the area was then a vast alluvial plain crossed by rivers, not the seabed. Industry-derived samples continue to unlock ancient ecosystems that traditional mining surveys pass right through. Like the Norwegian one, the fossil found in north China is a reminder that drill cores deep underground, seemingly relevant only to mining, can also hold keys to the ancient world,
Xing said.
Anatomy of a Juvenile Ornithischian
Bayan Gobi Formation
The recovered material is fragmentary rather than a complete skeleton. According to the study, the specimen comprises a sacral rib, four caudal vertebral centra, six caudal neural arches, several transverse processes, and ossified tendons. According to the study, the specimen includes part of a rib, four tail vertebrae and six bony arches from the tail. The bones had not yet fused, suggesting the dinosaur died as a juvenile.
Xing Lida, co-author and dinosaur expert
