No dinosaur stands alone. Every time a new species is announced, that dinosaur is placed into the context of all that have come before. It's another evolutionary branch that helps us better understand the shape of the dinosaur family tree. And sometimes, when new dinosaurs emerge, they have unexpected connections.



Earlier this month paleontologist Rafael Royo-Torres and colleagues described a new sauropod dinosaur found in the roughly 135 million year old strata of eastern Utah. The jumble of bones recovered from the site includes most of the species' skeleton, including an articulated foot that hints this dinosaur might have wound up literally stuck in the mud. The researchers have named the dinosaur Mierasaurus bobyoungi. But what's surprising about this dinosaur, Royo-Torres and colleagues suggest, is that it has connections to sauropods that lived far away in space and time.

Mierasaurus is a turiasaur. I know that's not a household name, but stay with me for a second. Turiasaurs were a particular group of sauropod dinosaurs known only from the Late Jurassic rocks of Europe. Yet Mierasaurus - as well as the recently-named Moabosaurus - appear to be members of this group that lived in the Cretaceous of North America.



This surprise has some broad implications for how sauropods evolved and moved around the planet. Maybe there are other, older turiasaurs in North America that have gone unrecognized because no one thought they were on the continent. Or, as Royo-Torres and colleagues write, the Utah skeletons might document that this peculiar group of herbivores found a refuge in North America while going extinct in Europe. Either way, the dinosaurs had to wind up in North America somehow, and this will undoubtedly send experts back to museum collections and outcrops to track how a group that was thought to be strictly European wound up in Grand County, Utah. Chalk up another dinosaur and a whole bunch of questions.

Fossil Facts

Name: Mierasaurus bobyoungi

Meaning: Mierasaurus is named for 18th century explorer Bernardo de Miera y Pacheco, "the first European scientist to enter what is now Utah." The species name bobyoungi is in honor of paleontologist Bob Young.

Age: Cretaceous, about 135 million years ago.

Where in the world?: Grand County, Utah.

What sort of organism?: A sauropod dinosaur.

How much of the organism’s is known?: A partial skeleton and referred isolated bones including a lower jaw and femur.

References:

Royo-Torres, R., Upchurch, P., Kirkland, J., DeBlieux, D., Foster, J., Cobos, A., Alcala, L. 2017. Descendants of the Jurassic turiasaurs from Iberia found refuge in the Early Cretaceous of western USA. Scientific Reports. doi: 10.1038/s41598-017-14677-2

Previous Paleo Profiles:

The Light-Footed Lizard

The Maoming Cat

Knight’s Egyptian Bat

The La Luna Snake

The Rio do Rasto Tooth

Bob Weir's Otter

Egypt's Canine Beast

The Vastan Mine Tapir

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The Micro Lion

The Mystery Titanosaur

The Echo Hunter

The Lo Hueco Titan

The Three-Branched Cicada

The Monster of Minden

The Pig-Footed Bandicoot

Hayden's Rattlesnake Demon

The Evasive Ostrich Seer

The Paradoxical Mega Shark

The Tiny Beardogs

The Armored Fish King

North America's Pangolin

The Invisible-Tusked Elephant

The Mud Dragon

The Spike-Toothed Salmon

The Dream Coast Crocodile

Buriol's Robber

Ozimek's Flyer

The Northern Naustoceratopsian

The High Arctic Flyer

The Tomatillo From the End of the World

The Short-Faced Hyena

The Mighty Traveler from Egg Mountain

Keilhau's Ichthyosaur

Mexico's Ancient Horned Face

Mauricio Fernández's Plesiosaur

New Zealand's Giant Dawn Penguin

The Orange Sea Lion

Mongolia's Ginkgo Cousin

The Geni River Frog

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