恐龍卡第 1311 張，共 2 027 張

Oneirosaurus

名字的意思： “dream lizard”1

吃：肉滄龍類白堊紀晚期嚴格來說不是恐龍

Oneirosaurus was a fierce marine lizard that swam in the warm seas of Colombia about 87 million years ago. It was a mosasaur, a relative of modern snakes and lizards, and it hunted fish and other sea creatures with its sharp teeth.2 1

趣味小知識：這種海生爬蟲類在海裡游泳的時候，恐龍正在陸地上走路。大家都叫牠們恐龍，但牠們其實是爬蟲類的另一個分支。

生存年代

90 到 86 百萬年前4

白堊紀晚期

化石發現地

Lebrija, Santander, Colombia1

長度

4 m (13 ft)3

最高速度

時速約 37 公里（23 英里）

游泳, 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？

跟 4 隻狗從鼻子接到尾巴一樣長跟 22 根香蕉頭尾相接一樣長能在 4.9 秒內游完一座大泳池（50 公尺）

Oneirosaurus 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)

Oneirosaurus 時速約 37 公里 (23 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

Oneirosaurus had a unique feature: two holes in its skull for nerves X, XI, and XII to exit, a trait not seen in any other plioplatecarpine mosasaur.1

Its name means 'dream lizard,' because the scientists who described it thought finding such a complete fossil was like a dream.1

Oneirosaurus lived during the Coniacian stage, about 89.8 to 85.7 million years ago, in a shallow sea that covered what is now Colombia.2

The only known fossil of Oneirosaurus is a nearly complete skull with a lower jaw and a disarticulated atlas (the first neck vertebra).2

Oneirosaurus belonged to a group of mosasaurs called Plioplatecarpinae, which were medium-sized, fast-swimming predators.2

Its teeth had two sharp edges (carinae) arranged 180 degrees apart, perfect for slicing through flesh.2

Oneirosaurus 的 AI 繪圖 — 這是電腦根據科學家目前的知識，用 AI 畫出 Oneirosaurus 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。

給恐龍專家

學名: Oneirosaurus
命名者: Páramo Fonseca et al. 20254
類群: 滄龍類
科 / 演化支: Mosasauridae4
分類: Mosasauroidea4
岩石的年代: 90 到 86 百萬年 (Coniacian)4
岩層: Galembo4
國家: 哥倫比亞4
化石紀錄: The Paleobiology Database 收錄 1 筆4
發現: Oneirosaurus was named in 2025 by María Eurídice Páramo Fonseca and colleagues, based on a skull found in the Galembo Formation of Colombia.1
仍有爭議: Scientists are still debating exactly how Oneirosaurus is related to other plioplatecarpine mosasaurs, especially its closeness to Yaguarasaurus columbianus and Ectenosaurus clidastoides.1