恐龍卡第 1144 張，共 2 027 張

Martinectes

名字的意思： “Martin's swimmer”1

吃：肉蛇頸龍類白堊紀晚期嚴格來說不是恐龍

Martinectes was a small, fast-swimming marine reptile that lived in the shallow seas of North America during the time of the dinosaurs. It had a short neck, a long snout, and four big flippers that helped it chase after fish and squid.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

84 到 72 百萬年前3

白堊紀晚期

化石發現地

South Dakota, Texas, and Wyoming, USA3

長度

2.3 到 2.6 m (7.5 到 8.5 ft)1

體重

1.27 公噸 (2,800 lb)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？

牠有多重？

跟 64 隻狗一樣重

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跟 250 顆西瓜一樣重跟 67 個幼兒園小朋友一樣重跟 40 個小學生一樣重跟 3 隻北極熊一樣重能在 6.9 秒內游完一座大泳池（50 公尺）

Martinectes 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)

Martinectes 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

Martinectes was one of the smallest adult polycotylid plesiosaurs ever found, measuring only about 2.3 to 2.6 metres long.1

It had large eyes with a bony ledge above them, which may have shaded its eyes from sunlight while hunting near the water's surface.1

Martinectes lived about 80 million years ago in the Western Interior Seaway, a huge ocean that split North America in two.1

Its name means 'Martin's swimmer', honoring the person who helped discover its fossils.1

Martinectes was originally thought to be a species of Dolichorhynchops, but scientists gave it its own genus in 2024.1

It had unusually wide bones in its spine and a very short back part of its skull, which helped scientists tell it apart from other plesiosaurs.1

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

?How big was Martinectes?

Martinectes was a large polycotylid plesiosaur, measuring at least around 5 metres (16 ft) long. Some estimates suggest it could reach up to 6 to 7 metres (20 to 23 ft), while a 2026 estimate put it at about 4.95 metres (16.2 ft) long.2

?Was Martinectes a dinosaur?

No, Martinectes was a plesiosaur, a marine reptile that lived in the seas during the time of the dinosaurs. It was not a dinosaur.2

?What did Martinectes eat?

Martinectes likely chased after fish and squid, using its long snout and four big flippers to swim fast. Its small teeth and narrow jaws suggest it ate small, slippery prey.2

給恐龍專家

學名: Martinectes
命名者: Clark et al. 20243
類群: 蛇頸龍類
科 / 演化支: Polycotylidae3
分類: Plesiosauria > Sauropterygia3
岩石的年代: 84 到 72 百萬年 (Campanian)3
岩層: Pierre Shale, Taylor Marl3
國家: 美國3
化石紀錄: The Paleobiology Database 收錄 3 筆3
發現: Martinectes was named in 2024 by Robert O. Clark, F. Robin O'Keefe, and Sara E. Slack. They studied fossils that had been found in Wyoming and South Dakota, USA, and realized they belonged to a new genus.3 1
仍有爭議: Scientists are still debating exactly how Martinectes used its unusual eye ledges and wide skull for hunting.1