恐龍卡第 0072 張，共 2 027 張

Alexeyisaurus

名字的意思： “Alexey's lizard”1

吃：肉蛇頸龍類三疊紀晚期嚴格來說不是恐龍

Alexeyisaurus was a long-necked marine reptile that swam in the oceans during the Late Triassic, about 210 million years ago. It was not a dinosaur, but a plesiosaur, a type of sea creature with a small head and four flippers. It lived near what is now Franz Josef Land in Russia.1 2

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

227 到 211 百萬年前5

三疊紀晚期

化石發現地

Wilczek Land, Franz Josef Land, Russia1

長度

7 m (23 ft)2

最高速度

時速約 26 公里（16 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 7 隻狗從鼻子接到尾巴一樣長跟 39 根香蕉頭尾相接一樣長能在 6.9 秒內游完一座大泳池（50 公尺）

Alexeyisaurus 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)

Alexeyisaurus 時速約 26 公里 (16 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

Alexeyisaurus is one of the earliest known plesiosaurs, living during the Late Triassic period.3

Its body was about 7 meters (23 feet) long, which is as long as a small bus.2

The humerus (upper arm bone) was straight and very long, with flat ends that suggest the head of the bone was not fully hardened.2

Its femur (thigh bone) was slightly curved and had wider ends than the humerus, giving it a different shape.2

The vertebrae (back bones) were strictly amphicoelous, meaning they were hollow on both ends like a dumbbell.2

Scientists first thought Alexeyisaurus was an elasmosaur, but later studies say the skeleton is too poorly preserved to be sure.1

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

?Was Alexeyisaurus a dinosaur?

No, it was not a dinosaur. It was a plesiosaur, a type of long-necked marine reptile that lived in the ocean.4 1

?How big was Alexeyisaurus?

It was about 7 meters (23 feet) long, which is as long as a small bus.4

?When did Alexeyisaurus live?

It lived during the Late Triassic period, about 210 million years ago.4 1

給恐龍專家

學名: Alexeyisaurus
命名者: Sennikov and Arkhangelsky 20105
類群: 蛇頸龍類
科 / 演化支: Elasmosauridae5
分類: Plesiosauria > Elasmosauridae > Sauropterygia5
岩石的年代: 227 到 211 百萬年 (Norian)5
岩層: Wilczek5
國家: 俄羅斯5
化石紀錄: The Paleobiology Database 收錄 1 筆5
發現: Alexeyisaurus was named by Russian paleontologists A. G. Sennikov and M. S. Arkhangelsky in 2010, based on an incomplete skeleton found on Wilczek Land in the Arctic.1 2
仍有爭議: Scientists are not sure if Alexeyisaurus was really an elasmosaurid plesiosaur, because the only skeleton found is incomplete and poorly preserved.1