Independent: Dinosaur Fossils in Washington and Alaska Tell the Story of an Ancient Catastrophe

Fossils unearthed in Washington state and Alaska are providing dramatic new evidence of the catastrophic events that ended the Age of Dinosaurs 66 million years ago.

In Washington’s Swauk Formation and Alaska’s Prince Creek Formation, palaeontologists have recovered the remains of hadrosaurs, tyrannosaurids, and other dinosaurs that lived in the final few million years of the Cretaceous. These specimens, many found in coastal and deltaic deposits, show clear signs of extreme environmental stress: stunted growth rings in bones, unusual isotopic signatures indicating sudden cooling and food shortages, and a sharp drop in diversity right before the boundary.

The fossils coincide with the global iridium anomaly and shocked quartz linked to the Chicxulub asteroid impact. In Alaska, some bones even preserve evidence of the “impact winter” — a period of prolonged darkness and freezing temperatures caused by dust and sulphur aerosols blocking sunlight. The presence of these dinosaurs so far north, surviving in polar forests, makes their sudden disappearance even more striking.

Researchers note that the Washington and Alaska sites capture the final chapter of dinosaur history in high-laтιтude ecosystems that were already vulnerable to climate swings. The catastrophe — a combination of the asteroid strike and mᴀssive Deccan Traps volcanism — delivered a one-two punch that wiped out non-avian dinosaurs worldwide.

From the misty forests of ancient Alaska to the coastal plains of Washington, these fossils are not just bones — they are eyewitnesses to the day the world changed forever. Paleontology’s record of the end-Cretaceous extinction just gained some of its most compelling high-laтιтude chapters.