恐龍卡第 0191 張，共 2 027 張

Atopodentatus

名字的意思： “unusual tooth”1

吃：植物海生爬蟲類三疊紀中期嚴格來說不是恐龍

Atopodentatus was a weird marine reptile that lived in the sea about 245 million years ago. It had a hammer-shaped head and used its special teeth to scrape algae off rocks, like a underwater lawnmower.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

244 到 243 百萬年前3

三疊紀中期

化石發現地

Luoping County, Yunnan Province, China1

長度

2.75 m (9 ft)1

最高速度

時速約 22 公里（14 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 15 根香蕉頭尾相接一樣長能在 8.2 秒內游完一座大泳池（50 公尺）

Atopodentatus 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)

Atopodentatus 時速約 22 公里 (14 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

Atopodentatus is the oldest known plant-eating marine reptile. It lived about 6 million years after the great Permian extinction.2

Its head was shaped like a hammer, similar to a hammerhead shark. But Atopodentatus used its hammerhead for grazing on algae, not for sensing prey.2

The front of its jaws had chisel-shaped teeth for scraping algae. The back of its jaws had a mesh of needle-shaped teeth that acted like a strainer.2

Atopodentatus was about 2.75 meters (9 feet) long, about as long as a small car.1

Scientists first thought Atopodentatus had a downturned snout and was a filter feeder. But new skulls in 2016 showed it actually had a hammerhead.1

Atopodentatus lived in shallow seas near the coast, where algae grew on rocks. It probably could walk on land or mudflats.1

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

?What did Atopodentatus eat?

Atopodentatus ate algae, scraping it off rocks with its chisel-shaped front teeth and filtering the bits with needle-like teeth in the back of its mouth.1 2

?How big was Atopodentatus?

Atopodentatus was about 2.75 meters (9 feet) long, roughly the size of a large dog.1

?Was Atopodentatus a dinosaur?

No, Atopodentatus was a marine reptile called a sauropterygian, not a dinosaur. It lived in the sea, not on land.1

?Why did Atopodentatus have a hammer-shaped head?

The hammer-shaped head helped Atopodentatus scrape algae off the seabed. Its wide jaws had chisel-like teeth for scraping, and the shape was unique among marine reptiles.2 1

?When did Atopodentatus live?

Atopodentatus lived about 247 to 240 million years ago, during the Middle Triassic period, about 6 million years after the Permian extinction.1

?Could Atopodentatus walk on land?

Scientists think Atopodentatus was semi-aquatic and could probably walk on land or mudflats, based on its body structure.1

迷思破解王

迷思： Atopodentatus was a filter feeder that sucked up small animals from the seafloor.

真相： New fossils show it had a hammer-shaped head and used its front teeth to scrape algae, then filtered the plant bits through its back teeth. It was a plant eater.2

給恐龍專家

學名: Atopodentatus
命名者: Cheng et al. 20143
類群: 海生爬蟲類
科 / 演化支: Sauropterygia3
分類: Sauropterygia3
岩石的年代: 244 到 243 百萬年 ()3
岩層: Guanling3
國家: 中國3
化石紀錄: The Paleobiology Database 收錄 2 筆3
發現: The first fossil of Atopodentatus was found near Daaozi village in Yunnan, China. Scientists named it in 2014. The name means 'unusual tooth' because of its strange teeth.1
仍有爭議: Scientists are not sure exactly how Atopodentatus is related to other marine reptiles. It is considered a strange type of sauropterygian.2