恐龍卡第 0600 張，共 2 027 張

Eonatator

名字的意思： “dawn swimmer”1

吃：肉滄龍類白堊紀晚期嚴格來說不是恐龍

Eonatator was a small, speedy marine lizard that swam in warm Cretaceous seas. It was an early relative of the giant mosasaurs, but much smaller and more agile.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

86 到 72 百萬年前3

白堊紀晚期

化石發現地

Kansas and Alabama, USA; southern Sweden; and Coello, Colombia1

長度

2.6 m (8.5 ft)1

最高速度

時速約 30 公里（19 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 2.5 隻狗從鼻子接到尾巴一樣長跟 14 根香蕉頭尾相接一樣長能在 6 秒內游完一座大泳池（50 公尺）

Eonatator 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)

Eonatator 時速約 30 公里 (19 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

Eonatator's tail made up about 40% of its head and body length, helping it swim fast.1

The first Eonatator fossil was found in the Niobrara Chalk of Kansas in 1918 by Charles Hazelius Sternberg and his son Levi.1

Eonatator was originally thought to be a species of Clidastes or Halisaurus, but scientists gave it its own genus in 2005.1

A second species, Eonatator coellensis, was discovered in Colombia and named after the town of Coello.1

Eonatator had a smooth, triangular bone on top of its skull with a round hole called the parietal foramen.1

Like many mosasaurs, Eonatator gave birth to live young instead of laying eggs.2

Eonatator 的 AI 繪圖 — 這是電腦根據科學家目前的知識，用 AI 畫出 Eonatator 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 Eonatator 最常被問的問題

?How big was Eonatator?

Eonatator was a small mosasaur. The type specimen of Eonatator sternbergii was about 2.6 metres (8.5 ft) long, and a specimen of Eonatator coellensis measured 2.8 metres (9.2 ft) long as preserved, missing part of its tail.1

?What did Eonatator eat?

The sources do not say exactly what Eonatator ate. As a small marine lizard and a mosasaur, it likely ate fish and other small sea creatures, but no specific diet is given.1

?Where was Eonatator found?

Eonatator fossils have been found in North America (Kansas and Alabama), Colombia, and Sweden. The first fossil was discovered in the Niobrara Chalk of Kansas in 1918.1

?Is Eonatator a dinosaur?

No, Eonatator is not a dinosaur. It is a marine lizard belonging to the mosasaur family.1

給恐龍專家

學名: Eonatator
命名者: Bardet et al. 20053
類群: 滄龍類
科 / 演化支: Mosasauridae3
分類: Mosasauroidea3
岩石的年代: 86 到 72 百萬年 (Santonian / Campanian)3
岩層: Niobrara, Nivel de Lutitas y Arenas3
國家: 瑞典, 美國, 哥倫比亞3
化石紀錄: The Paleobiology Database 收錄 9 筆3
發現: The first Eonatator fossil, a nearly complete skeleton, was found in Kansas in 1918 by Charles Hazelius Sternberg and his son Levi. It was named Eonatator sternbergii by Nathalie Bardet and colleagues in 2005.1
仍有爭議: Some scientists think Eonatator might actually belong to the genus Halisaurus, but most now accept it as a separate genus.1