恐龍卡第 1830 張，共 2 027 張

Trinacromerum

名字的意思： “three tipped femur”1

吃：肉蛇頸龍類白堊紀早期到白堊紀晚期嚴格來說不是恐龍

Trinacromerum was a fast-swimming marine reptile that lived in the Late Cretaceous seas. It used its long flippers like paddles to chase small fish. Even though it looked a bit like a dolphin, it was actually a plesiosaur, not a dinosaur.1 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

106 到 66 百萬年前4

白堊紀早期到白堊紀晚期

化石發現地

Kansas, Texas, Utah, and Wyoming in the USA, and Manitoba and Saskatchewan in Canada4 1

長度

3 m (9.8 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 17 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）

Trinacromerum 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)

Trinacromerum 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

Trinacromerum's long flippers helped it swim very fast, and scientists think it moved like a 'four-flippered penguin'.1

Its name means 'three tipped femur', which refers to a bone in its hip that had three points.1

Trinacromerum had 46 vertebrae in its spine, including 20 in the neck, 3 in the chest, and 23 in the back.2

Fossils of Trinacromerum have been found in rocks that were once the bottom of a shallow sea that covered central North America.4

It lived from about 106 to 66 million years ago, during the Late Cretaceous period.4

Some scientists once thought Trinacromerum was the same as another plesiosaur called Dolichorhynchops, but now they are considered different.2

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

?How big was Trinacromerum?

About 3 meters (9.8 feet) long. That is roughly the length of a small car.1 3

?What did Trinacromerum eat?

It ate small fish. Its teeth were shaped for catching and holding slippery prey.1 3

?Could Trinacromerum swim fast?

Yes, its long flippers helped it swim very fast. Scientists compare its swimming style to a 'four-flippered penguin.'1 3

?Is Trinacromerum a dinosaur?

No, it is a plesiosaur, which is a marine reptile. It lived in the sea and was not a dinosaur.1 3

迷思破解王

迷思： Some people think Trinacromerum was a dinosaur because it lived in the sea and had flippers.

真相： Trinacromerum was a plesiosaur, a marine reptile, not a dinosaur. Dinosaurs lived on land and had different body shapes.1

給恐龍專家

學名: Trinacromerum
命名者: Cragin 18884
類群: 蛇頸龍類
科 / 演化支: Polycotylidae4
分類: Plesiosauria > Sauropterygia4
岩石的年代: 106 到 66 百萬年 (Albian / Maastrichtian)4
岩層: Carlile Shale, Greenhorn Limestone, Pierre Shale4
國家: 美國, 加拿大4
化石紀錄: The Paleobiology Database 收錄 18 筆4
發現: Trinacromerum was first named by Francis W. Cragin in 1888 from fossils found in Kansas, USA. Later, more fossils were found in Canada and other parts of the USA.1 4
仍有爭議: Scientists still debate whether some fossils belong to Trinacromerum or to its close relative Dolichorhynchops, because their skeletons are very similar.2