恐龍卡第 1857 張，共 2 027 張

Umoonasaurus

名字的意思： “lizard of the Coober Pedy area, named after the local Antakirinja word 'Umoona'”1

吃：肉蛇頸龍類白堊紀早期嚴格來說不是恐龍

Umoonasaurus was a small, crested marine reptile that swam in cold seas near Antarctica about 115 million years ago. It had three bony crests on its head, like a tiny underwater dinosaur, but it was actually a plesiosaur, not a dinosaur. Its fossils are famous because they are preserved in beautiful blue opal.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

121 到 100 百萬年前5

白堊紀早期

化石發現地

South Australia, in opal mines near Coober Pedy, Andamooka, and other areas1

長度

2.5 m (8.2 ft)1 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 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 6.9 秒內游完一座大泳池（50 公尺）

Umoonasaurus 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)

Umoonasaurus 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

Umoonasaurus is known from several partial skeletons, and one of them is the most complete opalized vertebrate fossil ever found.1

It had three thin, blade-like crests on its skull: one along the top of its snout and a pair above its eyes. These crests may have been used for display, like a peacock's tail.1

Umoonasaurus lived in a cold, high-latitude inland sea near the South Pole, where water temperatures were near freezing.1 2

It was a small plesiosaur, only about 2.5 metres (8 feet) long as an adult. A juvenile specimen was less than 1 metre long.1

Umoonasaurus is the most primitive and also the last surviving member of its group, the rhomaleosaurids. It lived about 115 million years ago.1 2

Its tail ended in a 'pygostyle-like' structure made of fused vertebrae, similar to the tail tip of some modern birds.1

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

?What did Umoonasaurus eat?

Umoonasaurus ate small fish. Preserved gut contents show it ate small teleost fish.1

?Why did Umoonasaurus have crests?

Scientists think the three crests on its skull were used for display, like a peacock's tail, to help recognise each other or attract mates. They were too fragile for fighting.1

?Was Umoonasaurus a dinosaur?

No, Umoonasaurus was a plesiosaur, a type of marine reptile with four flippers. It was not a dinosaur.3 4 1

給恐龍專家

學名: Umoonasaurus
命名者: Kear et al. 20065
類群: 蛇頸龍類
科 / 演化支: Leptocleididae5
分類: Plesiosauria > Sauropterygia5
岩石的年代: 121 到 100 百萬年 (Aptian / Albian)5
岩層: Bulldog Shale5
國家: 澳洲5
化石紀錄: The Paleobiology Database 收錄 4 筆5
發現: Umoonasaurus was named in 2006 by Benjamin Kear and colleagues. The holotype skeleton, nicknamed 'Eric', was bought by public donations and is preserved in opal from the Zorba Extension Opal Field near Coober Pedy, Australia.1
仍有爭議: Scientists are not sure what the three crests on its head were used for. They were too fragile for fighting, so they might have been for display or recognizing other Umoonasaurus.1