Question 1

How do you say Utatsusaurus?

Accepted Answer

You say it oo-TAT-soo-SOR-us. Break it into four chunks: oo, like the sound in 'boo,' then TAT, then soo, then SOR-us like the end of 'dinosaur.' The tricky part is the middle, so try saying 'oo-TAT-soo' a few times fast before adding the 'SOR-us' at the end. Once you nail it, it's actually pretty fun to say out loud.

Question 2

What does Utatsusaurus mean?

Accepted Answer

Utatsusaurus means 'Utatsu lizard.' The first part of the name comes from Utatsu-cho, a small coastal town in Miyagi Prefecture, Japan, where the very first fossils of this animal were discovered. The ending 'saurus' comes from the Greek word 'sauros,' which means lizard, and it gets tacked onto the end of hundreds of prehistoric reptile names. So the full name is essentially a geographic shout-out to the Japanese town that gave up this ancient treasure.

Question 3

What kind of animal was Utatsusaurus?

Accepted Answer

Utatsusaurus was not a dinosaur. It was an ichthyopterygian, meaning it belonged to the group of reptiles that were evolving from land-dwelling ancestors into fully marine ocean swimmers. It is the earliest known member of this group, which eventually gave rise to the famous dolphin-shaped ichthyosaurs. Utatsusaurus looked more like a large eel or sea snake than a dolphin, with a slender flexible body up to 3 meters long and transitional paddle-like limbs.

Question 4

How old is Utatsusaurus?

Accepted Answer

Utatsusaurus lived approximately 248 to 246.7 million years ago, during the Early Triassic period. To put that in perspective, the dinosaurs had not even appeared yet when Utatsusaurus was alive. It swam ancient oceans just a few million years after the Permian-Triassic mass extinction, the deadliest extinction event in Earth's history, which wiped out more than 90 percent of all marine species. Utatsusaurus was essentially one of the first large marine reptiles to bounce back and claim the recovering oceans.

Question 5

How big was Utatsusaurus?

Accepted Answer

Utatsusaurus grew to about 2.5 to 3 meters long, which works out to roughly 8 to 10 feet. That is about as long as a standard couch and a half, or close to the length of a small car. It had a slender, eel-like build rather than a bulky one, so it was long and lean rather than heavy. Scientists estimate it probably weighed somewhere in the range of 50 to 100 kilograms, roughly comparable to a large adult human.

Question 6

Where did Utatsusaurus live?

Accepted Answer

Utatsusaurus fossils have been found in two very different places on the modern map: Miyagi Prefecture in Japan, and British Columbia in Canada. In Utatsusaurus's time, these were both coastal zones along the massive Panthalassic Ocean, the enormous ocean that covered most of the Earth when all the continents were still joined together as Pangaea. The fact that its fossils turn up on both sides of the modern Pacific Ocean tells us it was a wide-ranging swimmer capable of crossing vast stretches of open sea.

Question 7

Was Utatsusaurus the first ichthyosaur?

Accepted Answer

Utatsusaurus is currently recognized as the earliest known ichthyopterygian, the broader group that includes true ichthyosaurs and their closest relatives. It is so primitive that scientists placed it in its own separate family, Utatsusauridae, rather than grouping it with the more advanced ichthyosaurs. Whether it is technically 'the first' depends on how you define the group, but as of current scientific knowledge it sits at the very base of the ichthyopterygian family tree, making it the oldest known member of that lineage at roughly 248 million years old.

Question 8

Did Utatsusaurus live with dinosaurs?

Accepted Answer

No, Utatsusaurus lived well before the age of dinosaurs truly began. It swam the Early Triassic seas around 248 million years ago, and the earliest dinosaurs did not appear until roughly 230 to 233 million years ago, during the Late Triassic. So Utatsusaurus was already gone by the time the first dinosaurs were evolving on land. The two groups never overlapped, which makes Utatsusaurus a creature of a truly different era, a time when the planet was still recovering from the worst mass extinction it had ever experienced.

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