Dino card No. 0682 of 2,027

Futabasaurus

Name means: “Futaba lizard”1

Ate: MeatPlesiosaursLate CretaceousNot technically a dinosaur

Futabasaurus was a long-necked marine reptile that swam in the seas around Japan about 85 million years ago. It was not a dinosaur but a plesiosaur, a type of ocean predator. Its fossils were found by a high school student!1

Fun fact: this sea reptile swam while dinosaurs walked on land. Everyone calls them dinos, but they were a different branch of reptiles.

Lived

86 to 84 million years ago5

Late Cretaceous

Fossils found in

Fukushima Prefecture, Japan1

Food

Meat2

Length

6.4 to 9.2 m1

estimated range

When did it live?

Triassic

Jurassic

Cretaceous

252 million years ago20114566, the asteroid

How big was it?

as long as 2 cars parked in a rowas long as 51 bananas end to end

How big was Futabasaurus compared to YOU?

Just maths in your browser. Nothing is saved or sent anywhere.

cool stuff

Fun facts

Futabasaurus is the first elasmosaurid plesiosaur ever found in Japan.1

Its bones show bite marks from sharks, especially a type called Cretalamna, which scavenged or attacked it after death.1

The name Futabasaurus comes from the Futaba Group of rocks where it was discovered.1

The species name suzukii honors Tadashi Suzuki, the high school student who found the fossils.1

Futabasaurus lived during the Santonian stage of the Late Cretaceous, about 86 to 83 million years ago.2

It had a long neck like other elasmosaurids, and its front flippers were longer than its back ones.1

AI-made picture of Futabasaurus — An AI-made picture of how Futabasaurus might have looked, made by a computer from what scientists know. It is a guess: the real animal may have looked different, and nobody knows its true colours.

you asked

Most asked questions about Futabasaurus

?Was Futabasaurus a dinosaur?

No, Futabasaurus was a plesiosaur, a marine reptile, not a dinosaur. Its legs grew outwards from the body, unlike dinosaurs whose legs are directly underneath.3 1

?How big was Futabasaurus?

Futabasaurus was over 6 metres long, possibly between 6.4 and 9.2 metres. That is about as long as a bus.1 4

?What did Futabasaurus eat?

Futabasaurus was a predator, but its exact diet is not known. It likely ate fish and other sea animals, as other plesiosaurs did.1

?When did Futabasaurus live?

Futabasaurus lived about 85 million years ago, during the Late Cretaceous Period, in the Santonian stage.1 3

?Who discovered Futabasaurus?

Futabasaurus was discovered in 1968 by Tadashi Suzuki, who was a high school student at the time. He found the fossil in Fukushima, Japan.1 3

?Why is it called Futabasaurus?

It is named after the Futaba Group of rocks in Japan where it was found. The species name suzukii honors its discoverer, Tadashi Suzuki.1

Ask Rex about Futabasaurus

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Myth buster

Myth: Futabasaurus is a dinosaur.

Truth: Futabasaurus is a plesiosaur, a marine reptile, not a dinosaur. Dinosaurs lived on land.1

For dino experts

Scientific name: Futabasaurus
Named by: Sato et al. 20065
Group: Plesiosaurs
Family / clade: Elasmosauridae5
Classification: Plesiosauria > Elasmosauridae > Sauropterygia5
Age of the rocks: 86 to 84 million years (Santonian)5
Rock formations: Tamayama5
Countries: Japan5
Fossil records: 1 in the Paleobiology Database5
Discovery: The fossils were found by high school student Tadashi Suzuki in the Irimazawa Member of the Tamayama Formation in Fukushima, Japan. Scientists Tamaki Sato, Yoshikazu Hasegawa, and Makoto Manabe named it in 2006.1
Still debated: Scientists are not sure exactly how long Futabasaurus was, with estimates ranging from 6.4 to 9.2 metres.1

Where the facts come from

Futabasaurus (en.wikipedia.org)
PBDB Taxon (paleobiodb.org)
50 Years Since the Discovery of Futabasaurus Suzukii in Iwaki (city.iwaki.lg.jp)
A new elasmosaurid plesiosaur from the Upper Cretaceous of Fukushima, Japan (researchgate.net)
Futabasaurus in The Paleobiology Database (CC BY 4.0): age, places, rock formations, classification.

Every fact on this page has a number that points to its source. If we got something wrong, sorry, we are dino fans, not a science journal. Tell us at [email protected] and we will fix it.

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