恐龍卡第 1487 張，共 2 027 張

Protognathus

名字的意思： “early jaw lizard”1

吃：植物長脖子恐龍侏羅紀中期到侏羅紀晚期

Protognathosaurus was a big, long-necked plant eater that lived in China during the Middle Jurassic. It is known from just a piece of its lower jaw, so scientists are still figuring out exactly what it looked like.1

生存年代

171 到 155 百萬年前3

侏羅紀中期到侏羅紀晚期

最高速度

時速約 15 公里（9 英里）

跑步, 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)

Protognathus 時速約 15 公里 (9 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

Protognathosaurus is known only from a single piece of lower jaw, called a dentary, which had about 18 tooth positions.1

Its name was first Protognathus, but that name was already used for a beetle, so in 1991 it was changed to Protognathosaurus.1

The jaw shows sharp replacement teeth still growing in, which is why the species name oxyodon means 'sharp tooth'.1

It lived about 168 to 161 million years ago, during the Middle Jurassic.1

The fossil was found in the Lower Shaximiao Formation, which is made of sandstone and mudstone from an ancient lake.2

Scientists think it was a medium-sized primitive sauropod, with a thick and heavy lower jaw.2

Protognathus 的 AI 繪圖 — 這是電腦根據科學家目前的知識，用 AI 畫出 Protognathus 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： Some people think Protognathosaurus is a fake or made-up dinosaur because it is so incomplete.

真相： It is a real dinosaur, but many scientists consider it a nomen dubium, meaning the name is doubtful because the fossil is too fragmentary to be sure.1

給恐龍專家

學名: Protognathus
命名者: Zhang 19883
類群: 長脖子恐龍
科 / 演化支: Cetiosauridae3
分類: Sauropodomorpha > Sauropoda3
岩石的年代: 171 到 155 百萬年 (Bajocian / Oxfordian)3
化石紀錄: The Paleobiology Database 收錄 1 筆3
發現: In 1988, Zhang Yihun named and described the type species Protognathus oxyodon from a jaw found in China. In 1991, George Olshevsky renamed it Protognathosaurus because the old name was already taken.1
仍有爭議: Scientists debate whether Protognathosaurus is a valid genus or just a nomen dubium, because the only fossil is a piece of jaw.1