恐龍卡第 1601 張，共 2 027 張

Scalamagnus

名字的意思： “large staircase, referring to the Grand Staircase-Escalante National Monument where it was found”1

吃：肉蛇頸龍類白堊紀晚期嚴格來說不是恐龍

Scalamagnus was a small, fast-swimming marine reptile that lived in the warm, shallow sea that once covered North America. It had a long snout full of sharp teeth and used its four flippers to zoom through the water after fish and squid.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

94 到 90 百萬年前2

白堊紀晚期

化石發現地

Utah, USA, in the Tropic Shale formation1 2

長度

3.2 m (10 ft)1

最高速度

時速約 28 公里（17 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 3 隻狗從鼻子接到尾巴一樣長跟 18 根香蕉頭尾相接一樣長能在 6.4 秒內游完一座大泳池（50 公尺）

Scalamagnus 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)

Scalamagnus 時速約 28 公里 (17 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

Scalamagnus was originally thought to be a species of Dolichorhynchops, but scientists later gave it its own name in 2023.1

One Scalamagnus skeleton was found with 289 stomach stones (gastroliths), which is very unusual for this group of plesiosaurs.1

The stomach stones weighed about 518 grams in total, and most were smaller than 2 grams.1

It lived about 93 to 91 million years ago, during the early Turonian stage of the Late Cretaceous.1

Scalamagnus was a polycotylid plesiosaur, a group known for having short necks and large heads, unlike the long-necked plesiosaurs.1

The name Scalamagnus honors the Grand Staircase-Escalante National Monument in Utah, where its fossils were dug up.1

Scalamagnus 的 AI 繪圖 — 這是電腦根據科學家目前的知識，用 AI 畫出 Scalamagnus 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: Scalamagnus
命名者: Clark et al. 20242
類群: 蛇頸龍類
科 / 演化支: Polycotylidae2
分類: Plesiosauria > Sauropterygia2
岩石的年代: 94 到 90 百萬年 (Turonian)2
岩層: Tropic Shale2
國家: 美國2
化石紀錄: The Paleobiology Database 收錄 2 筆2
發現: The first fossils were found between 2003 and 2005 by the Museum of Northern Arizona in the Tropic Shale of Utah. It was named Scalamagnus tropicensis in 2023 by Robert Clark, Robin O'Keefe, and Sara Slack.1 2
仍有爭議: Scientists are not sure why Scalamagnus had so many stomach stones, since most other polycotylids did not have them.1