Fossils, monsters and words
Octopus relatives were swimming long before the dinosaurs, and people have been telling stories about them for thousands of years.
Older than the dinosaurs
The oldest known octopus relative lived about 330 million years ago, long before the dinosaurs. Its fossil, from Montana, has ten limbs. Smithsonian Magazine: Ten wild facts about octopuses · checked 28 Oct 2026 Before that find, the oldest octopus fossil was Pohlsepia mazonensis, about 296 million years old, described as looking like a flattened ‘cow patty’. Smithsonian Magazine: Ten wild facts about octopuses
Only the chambered nautiluses still have a shell on the outside. Over 10,000 nautiloid species once lived; today just seven remain. Smithsonian Ocean: Octopuses, squids and relatives
Aristotle and the Kraken
People have been fascinated by cephalopods for a long time: Aristotle wrote about them often, around 350 BC. Smithsonian Ocean: Octopuses, squids and relatives Octopuses inspired sea monsters, from the Kraken of Nordic legend to the Caribbean’s Lusca. Smithsonian Magazine: Ten wild facts about octopuses
The word
‘Octopus’ comes from the Greek for ‘eight foot’. Smithsonian Magazine: Ten wild facts about octopuses The first known use of the word octopus in English was in 1759. Merriam-Webster: octopus
Merriam-Webster lists three plurals: octopuses, octopi and octopodes. Octopuses is now the most common. Merriam-Webster: octopus ‘Octopi’ is the oldest plural, made on the mistaken idea that the word was Latin. It is really Greek, which is where ‘octopodes’ comes from. Merriam-Webster: octopus
- Merriam-Webster lists three plurals: octopuses, octopi and octopodes. Octopuses is now the most common. Merriam-Webster: octopus
- ‘Octopi’ is the oldest plural, made on the mistaken idea that the word was Latin. It is really Greek, which is where ‘octopodes’ comes from. Merriam-Webster: octopus
All three are in the dictionary. Octopuses is the one most people use. Every disagreement we found →
Octopuses and fishing
In 1899 a Plymouth newspaper complained that common octopuses had become so abundant they had ‘quite ruined the fisheries’, eating crabs, lobsters and oysters. Smithsonian Ocean: Octopuses, squids and relatives There is no fishery aimed at octopus in Alaska, but giant Pacific octopuses are caught by accident in trawl, longline and pot fisheries, and NOAA monitors that catch. NOAA Fisheries: Octopus research in Alaska
