Fossil Friday: Iridotriton

Iridotrition prepares to make a run for it as a larger, grumpier salamander approaches.
A large, grumpy salamander warns the little twerp to bug off his lawn. Little Iridotriton apologizes profusely and hurries on its way.

Species: Iridotriton hechti (Eye-rid-o-try-ton heck-tie)

What it means: Rainbow newt

Other Species: None

Where I live: Utah, USA – The Morrison Formation

When to find me: The Late Jurassic period, about 150 million years ago.

My favorite food: Tiny, tiny creatures and plants in the soil and leaf litter.

My neighborhood: The Morrison Formation covers a huge expanse of land with a variety of different habitats teaming with life. Most of it was very much like the Serengeti of modern day Africa, only with prairies of drought-tolerant ferns and cycad relatives instead of grass. Dense woodlands of tall conifers like the modern araucaria, ginkgoes, and tree ferns would only lie in places of plentiful water such as the few permanent rivers. Other areas had far more sparse and shrubbier vegetation like the open woodlands of acacia trees in the Serengetti.

Life in this environment would’ve adapted to long months of harsh drought, followed by a few months of monsoon that flooded the rivers. Many of the larger herbivores may have migrated like the herds in Africa do today, while most carnivores stayed behind to feast on the dead and dying, or else become opportunistic hunters of less traditional diets for lean times, such as fish or turtles in the rivers.

A few of my neighbors: First let me share the plant-eating giants…

  • Long-necked sauropods like Apatosaurus, Brachiosaurus, Camarasaurus, Diplodocus, Barosaurus, Suuwassea, Supersaurus, Haplocanthosaurus, and Dystrophaeus.
  • Armored dinosaurs like Stegosaurus, Hesperosaurus, Mymoorapelta, and Gargoyleosaurus.
  • Two-legged ornithopods like Dryosaurus, Camptosaurus, and Nanosaurus

Monstrous meat-eaters in the neighborhood include dinosaurs like Allosaurus, Torvosaurus, Ceratosaurus, Saurophaganax, Marshosaurus, Ornitholestes, Coelurus, Elaphrosaurus, Tanycolagreus, Stokesosaurus, and Koparion.

Plus there are all the other creatures that might eat me…countless lizards, crocodile relatives on land and water, mammals, frogs, turtles, fish, and pterosaurs that patrol the skies!

Fun Facts:

  • Iridotriton is from the Greek. Iris (rainbow) + Triton (a newt). Rainbow actually comes from the Rainbow Park microsite at Dinosaur National Monument, not any speculation on the creature’s color. The species name is in honor of Max Hecht, who was one of the first people to describe salamander remains from the Morrison Formation.
  • Iridotriton is the most complete salamander specimen of Jurassic North America discovered so far.
  • Since salamanders are delicate creatures, they do not usually fossilize. There are some fossils of a larger salamander that have not yet been named. These fossils are mostly isolated vertebrae and a few limb fragments, but not enough diagnostic material to name a new genus. In other words, the fossils aren’t good enough to know what they are, or to tell if they’re all from the same creature or several different ones.
  • Iridotriton had strong legs for its size. It most likely lived in a similar way to modern mole salamanders, which live mostly on land and only lay eggs in temporary pools and ponds safe from fish that would eat them. Some burrow into the soil or leaf litter to stay safe and cool from both drought and predators.

Fossil Finds:

One individual. Mostly complete except for small skull bones, digits (fingers and toes), and the tip of the tail. It is articulated and preserved 3 dimensionally in its matrix, the rock that surrounds the bones. The rock had cracks in it so only part of the skeleton could be exposed, but powerful X-ray technology (high-resolution X-ray computed tomography, to be specific) allows paleontologists to see the entire skeleton.


Foster, John. Jurassic West: The Dinosaurs of the Morrison Formation and Their World. Indiana University Press, 2007

S. E. EVANS, C. LALLY, D. C. CHURE, A. ELDER, J. A. MAISANO, A Late Jurassic salamander (Amphibia: Caudata) from the Morrison Formation of North America, Zoological Journal of the Linnean Society, Volume 143, Issue 4, April 2005, Pages 599–616,

“Iridotriton.” National Park Service,

7 thoughts on “Fossil Friday: Iridotriton

  1. Hi Patricia. I have never hear of Iridotriton (though I do know of Liaoxitriton and Karaurus), so when are where did you first learn of it? It’s good to have a salamander debut on, but I will admit, I’ve gotten to learn something new, like with Fruitachampsa. I would definitely go ahead and call this amphibian Iris, but I’ll leave it up to you and your family. And today, the second batch of CollectA figures for 2021 has been announced.


    1. I’m going through a convenient list of fauna in my primary source, Jurassic West. 🙂 I check other sources to make sure if the information has been updated with new finds since the book’s publication. It’s an excellent resource, but there are always new fossils that change what we know. That’s one of the things I like so much about prehistoric life. It’s good to remember that we don’t know it all, and to keep an open mind about how little we actually know, that we are more open to new knowledge, and can find wonder in little things. We learn something new every day, and humility in how little we know brings more joy in the discovery.

      Liked by 1 person

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