UW News

Christian Sidor


May 21, 2021

Pandemic-era paleontology: A wayward skull, at-home fossil analyses and a first for Antarctic amphibians

An image showing a block of amphibian fossils from Early Triassic Antarctica

Researchers at the University of Washington and its Burke Museum of Natural History & Culture have discovered the first fossil evidence of an ancient amphibian, Micropholis stowi, from Antarctica. Micropholis lived in the Early Triassic, shortly after Earth’s largest mass extinction. It was previously known only from fossils in South Africa, and its presence in Antarctica has implications for how amphibians adapted to high-latitude regions in this dynamic period of Earth’s history.


August 27, 2020

Frequently asked questions: torpor in Antarctic Lystrosaurus

An artist's rendition of an ancient vertebrate called Lystrosaurus

This FAQ discusses evidence for a hibernation-like condition in Lystrosaurus, a mammal relative that lived in the Antarctic portion of Pangea about 250 million years ago. This discovery was enabled by high-resolution of incremental growth marks preserved in the tusks of Lystrosaurus.


Weathering the tough times: Fossil evidence of ‘hibernation-like’ state in 250-million-year-old Antarctic animal

An artist's rendition of an ancient vertebrate called Lystrosaurus

University of Washington scientists report evidence of a hibernation-like state in Lystrosaurus, an animal that lived in Antarctica during the Early Triassic, some 250 million years ago. The fossils are the oldest evidence of a hibernation-like state in a vertebrate, and indicate that torpor — a general term for hibernation and similar states in which animals temporarily lower their metabolic rate to get through a tough season — arose in vertebrates even before mammals and dinosaurs evolved.


January 31, 2019

Iguana-sized dinosaur cousin discovered in Antarctica, shows how life at the South Pole bounced back after mass extinction

An illustration of a forest in Antarctica 250 million years ago, showing reptiles that lived there.

Scientists have just discovered a dinosaur relative that lived in Antarctica 250 million years ago. The iguana-sized reptile’s genus name, Antarctanax, means “Antarctic king.”


March 28, 2018

Decade of fossil collecting in Africa gives new perspective on Triassic period, emergence of dinosaurs

an artist rendering of teleocrater, an early dinosaur relative

A University of Washington-led project spanning countries, years and institutions has attempted to reconstruct what the southern end of the world looked like during the Triassic period, 252 to 199 million years ago.


December 8, 2016

Frequently asked questions: odontoma in a gorgonopsian

Sketch of an extinct animal.

Answers to frequently asked questions about a 255-year-old tumor in a ‘pre-mammal.’


Fossilized evidence of a tumor in a 255-million-year-old mammal forerunner

A tumor next to a tooth.

University of Washington paleontologists have discovered a benign tumor made up of miniature, tooth-like structures embedded in the jaw of an extinct ‘mammal-like’ gorgonopsian. Known as a compound odontoma, this type of tumor is common to mammals today. But this animal lived 255 million years ago, before mammals even existed.


August 18, 2016

Paleontologists with the UW’s Burke Museum discover major T. rex fossil

Paleontologists prepare to remove a Tyrannosaurus rex skull from a fossil dig site in northern Montana and transport it to the Burke Museum at the University of Washington.

Paleontologists with the Burke Museum of Natural History and Culture and the UW have discovered a Tyrannosaurus rex, including a very complete skull. The find, which paleontologists estimate to be about 20 percent of the animal, includes vertebrae, ribs, hips and lower jaw bones.


August 13, 2015

‘Scarface,’ an ancient cousin to mammals, unearthed in Africa

Photograph of the skull of Ichibengops munyamadziensis.

A team of scientists has identified a new species of “pre-mammal” based on fossils unearthed in Zambia’s Luangwa Basin in 2009. The ancient, Dachshund-sized creature lived some 255 million years ago, in a time just before the largest mass extinction in Earth’s history. Its discoverers include Christian Sidor, professor of biology at the University of…


May 20, 2015

Burke Museum paleontologists discover the first dinosaur fossil in Washington state

The first dinosaur fossil from Washington state (left) is a portion of a femur leg bone (full illustration right) from a theropod dinosaur.

Burke Museum of Natural History and Culture paleontologists have documented the first dinosaur fossil from Washington state. The fossil was collected by a Burke Museum research team along the shores of Sucia Island State Park in the San Juan Islands.


April 29, 2013

Dinosaur predecessors gain ground in wake of world’s biggest biodiversity crisis — with photo gallery

Lizard-like animal with stripes stands in forested area

Newly discovered fossils reveal a lineage of animals thought to have led to dinosaurs taking hold in Tanzania and Zambia, many millions of years before dinosaur relatives were seen in the fossil record elsewhere on Earth.