Xunmenglong
Xunmenglong was a tiny, speedy meat-eater that lived in what is now China. It was one of the smallest dinosaurs of its group, about as long as a big chicken. It probably dashed around hunting small animals in the Early Cretaceous.12
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Fun facts
Xunmenglong is the smallest known member of the compsognathid group, about the size of a sub-adult Scipionyx, another small dinosaur.1
Its lower legs were unusually long compared to the rest of its body, which may have made it a fast runner.2
The fossil was originally part of a chimera, meaning it was mixed with bones from two other animals before scientists sorted it out.1
Xunmenglong lived about 130.7 million years ago, during the Hauterivian age of the Early Cretaceous.1
It is the oldest known compsognathid from Asia, found in the Huajiying Formation which may preserve the oldest Jehol Biota fauna.2
One unique feature is that its fourth toe bone (pedal phalanx IV-4) is longer than the third, which helps tell it apart from other compsognathids.2
Most asked questions about Xunmenglong
?How big was Xunmenglong?
It was about 50 centimetres (1.6 feet) long, roughly the size of a chicken.1
?What did Xunmenglong eat?
It was a meat-eater that probably hunted small animals like lizards and insects.1
?When did Xunmenglong live?
It lived about 130.7 million years ago, during the Early Cretaceous period.1
?Is Xunmenglong a dinosaur?
Yes, it is a compsognathid theropod dinosaur.1
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Myth buster
Myth: Some people might think Xunmenglong was a baby of a larger dinosaur because it was so small.
Truth: Scientists think it was a fully grown adult, not a baby, because its bones show adult features.1
For dino experts
- Scientific name
- Xunmenglong
- Named by
- Xing et al. 20203
- Group
- Meat-eating dinos
- Family / clade
- Compsognathidae3
- Classification
- Theropoda > Compsognathidae3
- Age of the rocks
- 133 to 126 million years (Hauterivian)3
- Rock formations
- Huajiying3
- Countries
- China3
- Fossil records
- 1 in the Paleobiology Database3
- Discovery
- Xunmenglong was named in 2020 by Xing and colleagues from a fossil that was part of a chimera. The holotype includes a pelvis, tail base, and hindlimbs, and it was found in the Huajiying Formation in China.12
- Still debated
- Scientists debate whether Xunmenglong is truly a compsognathid or a more basal member of Tetanurae, as one 2024 study suggested.1
Where the facts come from
- Xunmenglong (en.wikipedia.org)
- A new compsognathid theropod dinosaur from the oldest assemblage of the Jehol Biota in the Lower Cretaceous Huajiying Formation, northeastern China - ADS (ui.adsabs.harvard.edu)
- Xunmenglong in The Paleobiology Database (CC BY 4.0): age, places, rock formations, classification.
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