恐龍卡第 1954 張，共 2 027 張

Xunmenglong

名字的意思： “swift fierce dragon”1

吃：肉肉食恐龍白堊紀早期

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.1 2

生存年代

133 到 126 百萬年前3

白堊紀早期

化石發現地

Hebei Province, northeastern China, in the Huajiying Formation1 2

長度

0.5 m (1.6 ft)1

高度

0.19 m (0.6 ft)

估計值

最高速度

時速約 15 公里（9 英里）

跑步, 估計值

牠生活在什麼時候？

三疊紀

侏羅紀

白堊紀

2 億 5200 萬年前20114566，小行星撞地球

牠有多大？

牠有多長？

牠有多高？

估計值

跟 3 根香蕉頭尾相接一樣長跟 16 塊積木排成一排一樣長小到能從椅子底下走過去能在 24 秒內跑完 100 公尺（最快的人類要 9.6 秒）

Xunmenglong 跟「你」比起來有多大？

只是在你的瀏覽器裡算算數學。什麼都不會被儲存或傳送出去。

牠有多快？

走路的人 時速約 5 公里 (3 mph)

騎腳踏車的小朋友 時速約 12 公里 (7 mph)

Xunmenglong 時速約 15 公里 (9 mph)

一匹飛奔的馬 時速約 65 公里 (40 mph)

一隻獵豹 時速約 100 公里 (62 mph)

酷東西

趣味知識

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

Xunmenglong 的 AI 繪圖 — 這是電腦根據科學家目前的知識，用 AI 畫出 Xunmenglong 可能的樣子。這只是猜測：真正的動物可能長得不一樣，也沒有人知道牠真正的顏色。

你們都在問

關於 Xunmenglong 最常被問的問題

?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

迷思破解王

迷思： Some people might think Xunmenglong was a baby of a larger dinosaur because it was so small.

真相： Scientists think it was a fully grown adult, not a baby, because its bones show adult features.1

給恐龍專家

學名: Xunmenglong
命名者: Xing et al. 20203
類群: 肉食恐龍
科 / 演化支: Compsognathidae3
分類: Theropoda > Compsognathidae3
岩石的年代: 133 到 126 百萬年 (Hauterivian)3
岩層: Huajiying3
國家: 中國3
化石紀錄: The Paleobiology Database 收錄 1 筆3
發現: 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.1 2
仍有爭議: Scientists debate whether Xunmenglong is truly a compsognathid or a more basal member of Tetanurae, as one 2024 study suggested.1