Read in LevelsRead in Levels
a close up of an octopus under water

Photo by Oleksandr Sushko on Unsplash

Giant Octopuses Lived with Dinosaurs

natureApril 29, 2026·207 words·2 min read

This is a B1 (intermediate) English article about giant octopuses lived with dinosaurs. Read the article below, then check the key words and test your understanding with 5 exercises. You can also listen to the audio and tap any word to see its meaning.

Read & Listen

0:00 / 1:25
Giant Octopuses Lived with Dinosaurs
Scientists have found fossils of huge ancient octopuses. These animals lived in the oceans 100 million years ago, at the same time as dinosaurs. A team from Hokkaido University in Japan studied old jaw bones from Japan and Vancouver Island. The fossils show these octopuses grew to nearly 20 metres long. They were as big as the largest sea reptiles of their day.
Before this study, scientists thought the oldest octopuses with fins lived only about 15 million years ago. Octopuses have soft bodies, so they almost never become fossils. Only the hard jaw bones survive. To find the tiny jaws, the team used a special method called grinding tomography along with a computer model. The fossils belong to an extinct group of octopuses called Cirrata. They had strong jaws that could crush hard prey.
The most surprising thing was the wear on the jaws. Up to 10% of the tip was chipped, scratched, or cracked. That is more damage than we see in any octopus today. This means the ancient animals had a strong, aggressive way of eating. They probably attacked their prey with great force. The discovery changes the old idea that only animals with bones ruled the seas at the time of the dinosaurs.

Key Vocabulary

n.
old animal bones in stone
n.
from very long ago
n.
the bones in the mouth
n.
cold animals like snakes or lizards
adj.
no longer alive on Earth
n.
thin parts that help fish swim
adj.
ready to attack
n.
an animal that is eaten by another
v.
press hard to break
Vocabulary Translations· 9 words · 12 languages

Every definition is context-aware — translated based on how the word is used in this article, not a dictionary.

fossiln.

old animal bones in stone

hóa thạchfósseis化石fosillerfósilesskamielinyأحافيرfossielenокаменелости化石화석
ancientn.

from very long ago

cổ xưaantigos古代のantikantiguosstarożytneقديمةoeroudдревние远古的고대의
jawn.

the bones in the mouth

hàmmandíbulaçenemandíbulaszczękaفكkaakчелюсть
reptilen.

cold animals like snakes or lizards

loài bò sátrépteis爬虫類sürüngenlerreptilesgadyزواحفreptielenрептилии爬行动物파충류
extinctadj.

no longer alive on Earth

đã tuyệt chủngextinto絶滅したsoyu tükenmişextintowymarłyمنقرضuitgestorvenвымерший已灭绝的멸종된
finn.

thin parts that help fish swim

vâybarbatanasひれyüzgeçleraletaspłetwyزعانفvinnenплавники지느러미
aggressiveadj.

ready to attack

hung dữagressivo攻撃的なsaldırganagresivaagresywnyعدوانيagressiefагрессивный凶猛的공격적인
preyn.

an animal that is eaten by another

con mồipresa獲物avpresaofiaraفريسةprooiдобыча猎物먹이
crushv.

press hard to break

nghiền nátesmagar砕くezmekaplastarzmiażdżyćسحقverpletterenраздавить压碎으스러뜨리다

Check Your Understanding

Question 1: Multiple Choice

Why is it hard to find octopus fossils?

Question 2: Multiple Choice

What does the wear on the jaws tell us about how these octopuses ate?

Question 3: Fill in the Blank

These ancient octopuses had strong jaws that could ______ hard prey.

Question 4: Fill in the Blank

The fossils belong to an ______ group of octopuses called Cirrata.

Question 5: Put in Order

Put these ideas in the correct logical order.

1Scientists used a special method and a computer to find the tiny jaws.
2Ancient octopuses had soft bodies that broke down quickly after death.
3The team discovered that some octopuses grew almost 20 metres long.
4Only the hard jaw bones were left behind as fossils.

Dictation Practice

Sentence 1 / 170/8 words

Memorize Practice

Sentence 1 / 17

Read at Other Levels