Xingxiulong yueorum was a large, early-diverging sauropodomorph from the Lower Jurassic Lufeng Formation in Yunnan, China. Its estimated length is 8–10 metres (about 26–33 feet), so 33 feet is the upper end of the estimate, not an exact measured length. The discovery adds evidence that early sauropodomorph evolution was more complex than a simple march toward later giant sauropods; it does not, by itself, rewrite the history of Jurassic dinosaurs.
What is Xingxiulong yueorum?
It is a newly described species of sauropodomorph, the broader group that includes the long-necked sauropods and their earlier relatives. The species comes from the Lower Jurassic Lufeng Formation of Yunnan Province, China. Chen, Wang, Zhang, Wang and You described it in a 2025 paper in Historical Biology, published online on February 3, 2025. Read the paper record and abstract.
The description is based on postcranial material—skeletal remains from behind the skull. The authors distinguish X. yueorum from its close relative X. chengi by a combination of features in the thigh bone, ankle and foot:
- A pendant-shaped fourth trochanter that terminates toward the lower end of the femur.
- An astragalus (an ankle bone) with an almost straight dorsal margin on its rear surface.
- Two phalanges, or toe bones, on pedal digit V.
A phylogenetic analysis in the study supports the view that the two named species belong together in the genus Xingxiulong.
Do these 3 things before closing this tab:
1Clear out junk files and repair common Windows errors2Fix the driver behind crashes, sound loss and screen glitches3Repair Windows errors before they cause bigger problems#1 Best Overall
- Build from the Bones Up – Explore the internal structure with a “Skeleton Build” that reveals how the dinosaur was formed.
- Reconstruct the Beast – Add outer skin parts over the skeleton for a full, lifelike dinosaur model — a unique feature only possible with plastic model kits.
- No Tools Needed! – Snap-fit design means no glue or cutters required. Just build and enjoy.
- All-New Parts – Completely redesigned skin parts faithfully replicate the textures and shapes seen in the movie.
- The product box will have a Bandai Namco warning label, which is proof that you are purchasing an officially licensed product
How big was the dinosaur?
The Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences estimated X. yueorum at 8–10 metres long, using its 78-centimetre femur as a basis. Converted to feet, that is roughly 26–33 feet. The headline figure of 33 feet therefore represents the high end of an estimated range, not a direct measurement of a complete animal. The institute’s February 13, 2025 announcement also estimates X. chengi at 4–5 metres long; its largest individual had a 56-centimetre femur.
| Species | Estimated body length | Reported femur length |
|---|---|---|
| Xingxiulong yueorum | 8–10 m (about 26–33 ft) | 78 cm |
| Xingxiulong chengi | 4–5 m (about 13–16 ft) | 56 cm in its largest individual |
Both length estimates are from the Chinese Academy of Sciences institute announcement, not measurements of fully preserved skeletons. The available announcement identifies the femur basis but does not provide further detail on the reconstruction method.
Rank #2
- Highly-detailed and intricately painted sculpt.
- Figure measures approximately 7" tall.
- Collect all 3 officially licensed Jurassic Park dioramas!
- Ages 14+
What does its anatomy suggest about sauropodomorph evolution?
The most notable evolutionary point is a shared feature of both known Xingxiulong species: each had four sacral vertebrae, the vertebrae that connect the spine to the pelvis. The study authors note that four sacrals are typically associated with later-diverging sauropodiforms and sauropods. They interpret the condition as evidence of complexity in early sauropodomorph evolution.
“Both the two species of Xingxiulong have four sacral vertebrae, which are typically associated with the late-diverging sauropodiforms and sauropods, suggesting a complex early evolution within the sauropodomorphs.”
Free tools Windows power users keep installed
One-click scans. No signup required.
Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.Rank #3
BANDAI Hobby - Jurassic World - Titanosaurus - Jurassic Collaboration Plannosaurus Dinosaur Model Kit
- Learn from the Inside Out: Dive into dino anatomy with the Skeleton Build – a unique way to explore the internal structure before bringing the beast to life
- No Tools, No Glue, No Hassle: Easy snap-fit assembly means anyone can build it — no nippers, no adhesives, just pure fun!
- Dynamic Display Base Included: Comes with a custom ocean-themed base featuring the official Jurassic World logo plate
- Bonus Illustrated Backdrop: Set the scene with a vibrant background sheet to display your dino in action!
- The product box will have a Bandai Namco warning label, which is proof that you are purchasing an officially licensed product
That is a specific anatomical finding and the authors’ interpretation of it. It does not show that X. yueorum was a direct ancestor of later sauropods, nor does one shared feature establish that the broader picture of Jurassic evolution has been overturned. The finding instead adds another piece to the evidence for diversity and evolutionary complexity among early sauropodomorphs.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Why the discovery matters—and what it does not establish
X. yueorum expands the known diversity of dinosaurs from the Lufeng Formation and provides a distinctive set of postcranial traits for comparison with X. chengi and other sauropodomorphs. Its size estimate makes it notably larger than the estimate for that related species, while the four-sacral condition is relevant to how researchers understand changes within the group.
Rank #4
- Dinosaur toy set – Inspire a passion for dinosaur-related adventures in kids ages 9 and up with this Dinosaur Fossils: T. rex Skull set. The set offers fans a more challenging build for a fun display
- Dinosaur ‘fossil’ figure for boys and girls – Features a dino toy T. rex skull with dinosaur bones for kids, a ‘fossilized’ footprint and a stand to hold them, as well as a plaque and a hidden ‘amber’ piece
- Posable skull – With jaws that can open and close, the skull can be posed in different ways on the stand or in front of it with the ‘fossilized’ footprint
- Dinosaur LEGO set – Designed for kids who love dinosaurs, paleontological adventures or being a hero, this fun dinosaur gift will make a birthday or holiday present to create and display
- A new way to build – Let the LEGO Builder app guide kids on an intuitive building adventure. They can save sets, track progress, zoom in and rotate models in 3D while they build
The paper’s abstract and the institute’s announcement support those conclusions, but they do not establish a wholesale revision of dinosaur evolutionary history. The paper’s full text is restricted in the cited record, so detailed excavation chronology and additional specimen-level claims should not be inferred from the abstract alone.
Quick Recap
Best Value
- Learn from the Inside Out: Dive into dino anatomy with the Skeleton Build – a unique way to explore the internal structure before bringing the beast to life
- No Tools, No Glue, No Hassle: Easy snap-fit assembly means anyone can build it — no nippers, no adhesives, just pure fun!
- Dynamic Display Base Included: Comes with a custom ocean-themed base featuring the official Jurassic World logo plate
- Bonus Illustrated Backdrop: Set the scene with a vibrant background sheet to display your dino in action!
- The product box will have a Bandai Namco warning label, which is proof that you are purchasing an officially licensed product
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
