恐龍卡第 1040 張，共 2 027 張

Leurospondylus

名字的意思： “smooth vertebra”1

吃：肉蛇頸龍類白堊紀晚期嚴格來說不是恐龍

Leurospondylus was a plesiosaur, a long-necked marine reptile that lived in the Late Cretaceous period. It swam in rivers and estuaries in what is now Alberta, Canada. Scientists think it may have spent its early life in brackish water.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

72 到 66 百萬年前2

白堊紀晚期

化石發現地

Alberta, Canada (Horseshoe Canyon Formation, Red Deer River)1 2

長度

最多 2 m (6.6 ft)1

最高速度

時速約 27 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 4 隻家貓從鼻子接到尾巴一樣長跟 11 根香蕉頭尾相接一樣長能在 6.7 秒內游完一座大泳池（50 公尺）

Leurospondylus 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)

Leurospondylus 時速約 27 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

The only known fossil of Leurospondylus is a juvenile that was about 2 meters long. Adults may have been much larger.1

Its name means 'smooth vertebra' because its backbone bones were flat and wider than they were long.1

Leurospondylus lived in brackish water (a mix of fresh and salt water) in rivers and estuaries. This is unusual because most plesiosaurs lived in the open ocean.1

When it was first described in 1913, Leurospondylus was thought to be the last known plesiosaur fossil. Its species name 'ultimus' means 'last' in Latin.1

Scientists are not sure which family Leurospondylus belongs to. Its vertebrae look like those of pliosaurs, but its shoulder and hip bones resemble those of elasmosaurids.1

The fossil was found on the east bank of the Red Deer River in Alberta, Canada, in rocks that are about 72 to 66 million years old.2 1

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

迷思破解王

迷思： Leurospondylus was a dinosaur.

真相： Leurospondylus was a plesiosaur, a marine reptile that lived in the sea and rivers. Plesiosaurs are not dinosaurs.1

給恐龍專家

學名: Leurospondylus
命名者: Brown 19132
類群: 蛇頸龍類
科 / 演化支: Elasmosauridae2
分類: Plesiosauria > Elasmosauridae > Sauropterygia2
岩石的年代: 72 到 66 百萬年 (Maastrichtian)2
岩層: Horseshoe Canyon2
國家: 加拿大2
化石紀錄: The Paleobiology Database 收錄 1 筆2
發現: Leurospondylus was named by Barnum Brown in 1913 based on a juvenile fossil found in the Horseshoe Canyon Formation of Alberta, Canada.1 2
仍有爭議: Scientists still debate whether Leurospondylus belongs to the family Elasmosauridae or to a different group, because its bones show a mix of features.1