恐龍卡第 0084 張，共 2 027 張

Alzadasaurus

名字的意思： “Alzada lizard”4

吃：肉蛇頸龍類白堊紀晚期嚴格來說不是恐龍

Alzadasaurus was a long-necked marine reptile that swam in the seas of North America about 80 million years ago. It was not a dinosaur, but a plesiosaur, and it used its four flippers to paddle through the water. With sharp teeth, it hunted fish and other sea creatures.4

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

84 到 72 百萬年前4

白堊紀晚期

化石發現地

Montana, USA4

長度

10.86 到 11.95 m (36 到 39 ft)2

體重

4.4 公噸到 6.8 公噸 (9,700 到 15,000 lb)2

最高速度

時速約 22 公里（14 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？

牠有多重？

跟 5 台汽車一樣重

跟 2.5 台汽車排成一排一樣長跟 66 根香蕉頭尾相接一樣長大約跟一頭大象一樣重跟 1400 顆西瓜一樣重跟 8 整班小學生一樣重跟 15 隻北極熊一樣重能在 8.2 秒內游完一座大泳池（50 公尺）

Alzadasaurus 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)

Alzadasaurus 時速約 22 公里 (14 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

Alzadasaurus lived during the Late Cretaceous period, between about 83.6 and 72.2 million years ago.1

It belonged to a group of plesiosaurs called elasmosaurids, which had very long necks.4

Fossils of Alzadasaurus have been found in the Bearpaw Shale formation in Montana.4

Some scientists think Alzadasaurus might actually be the same animal as Thalassomedon, another elasmosaurid.4

Alzadasaurus was named by paleontologist Samuel Paul Welles in 1943.4

It is the type genus of the subfamily Alzadasaurinae, a group of elasmosaurids.4

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

?How big was Alzadasaurus?

Scientists are not sure of its exact size, but its close relative Thalassomedon was about 10.86 to 11.95 metres long and weighed 4.4 to 6.8 metric tons.2

?What did Alzadasaurus eat?

It was a carnivore that ate fish and other sea creatures, using its sharp teeth to catch them.4

?Is Alzadasaurus a dinosaur?

No, it is a plesiosaur, a marine reptile that lived in the sea. It is not a dinosaur.4

?When did Alzadasaurus live?

It lived during the Late Cretaceous period, between about 83.6 and 72.2 million years ago.4

?Could Alzadasaurus swim?

Yes, it was an aquatic marine reptile that used its four flippers to paddle through the water.4

?Where were Alzadasaurus fossils found?

Fossils have been found in Montana and South Dakota, in the Bearpaw Shale and Pierre formations.4 3

給恐龍專家

學名: Alzadasaurus
命名者: Welles 19434
類群: 蛇頸龍類
科 / 演化支: Elasmosauridae4
分類: Plesiosauria > Elasmosauridae > Sauropterygia4
岩石的年代: 84 到 72 百萬年 (Campanian)4
岩層: Bearpaw Shale4
國家: 美國4
化石紀錄: The Paleobiology Database 收錄 1 筆4
發現: Alzadasaurus was named by Samuel Paul Welles in 1943 based on fossils found in Montana, USA.4
仍有爭議: Scientists are not sure if Alzadasaurus is a distinct genus or if it should be considered the same as Thalassomedon.4