Dino card No. 0884 of 2,027

Isanosaurus

Say it: ee-SAH-no-SORE-us

Name means: “lizard from north-eastern Thailand”1

Ate: PlantsLong-necksEarly Jurassic

Isanosaurus was one of the very first long-necked sauropod dinosaurs. It walked on all four legs and lived in what is now Thailand during the Early Jurassic Period, about 197 to 192 million years ago.1 2

Lived

193 to 175 million years ago2

Early Jurassic

Fossils found in

Chaiyaphum Province, north-eastern Thailand1

Food

Plants2

Length

up to 6.5 m1

estimate based on a single, possibly not fully grown individual

When did it live?

Triassic

Jurassic

Cretaceous

252 million years ago20114566, the asteroid

How big was it?

as long as 4 bicycles in a rowas long as 36 bananas end to end

How big was Isanosaurus compared to YOU?

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cool stuff

Fun facts

Isanosaurus was one of the earliest sauropods, the group that later included giants like Brachiosaurus and Diplodocus.1

Its thigh bone is 76 centimetres long and very straight, showing it had column-like legs for walking on all fours.1

The only known skeleton was found in 1998 near the village of Ban Non Thaworn, but most of it had already eroded away.1

Isanosaurus had neck vertebrae that were ball-and-socket joints, making its neck flexible.1

Scientists used to think Isanosaurus lived in the Late Triassic, but in 2026 new dating showed it lived in the Early Jurassic.1

The tail vertebrae of Isanosaurus were hollow at both ends, like a double-sided cup.1

AI-made picture of Isanosaurus — An AI-made picture of how Isanosaurus 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.

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Myth buster

Myth: Isanosaurus was the oldest sauropod dinosaur.

Truth: It was once thought to be from the Late Triassic, but newer dating shows it lived in the Early Jurassic, about 197 to 192 million years ago. Other sauropods may be older.1

For dino experts

Scientific name: Isanosaurus
Named by: Buffetaut et al. 20002
Group: Long-necks
Family / clade: Sauropoda2
Classification: Sauropodomorpha > Sauropoda2
Age of the rocks: 193 to 175 million years (Pliensbachian / Toarcian)2
Rock formations: Nam Phong2
Countries: Thailand2
Fossil records: 1 in the Paleobiology Database2
Discovery: Isanosaurus was named in 2000 by French palaeontologist Éric Buffetaut and his team. The species name attavipachi honours P. Attavipach, a supporter of Thai palaeontology.1
Still debated: Scientists are not sure exactly how Isanosaurus is related to other early sauropods, because the only known fossils are very incomplete.1

Where the facts come from

Isanosaurus (en.wikipedia.org)
Isanosaurus 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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