New evidence that dinosaurs died in the spring

Today’s Video of the Day from the European Synchrotron Radiation Facility (ESRF) describes the details of a new study which reveals that dinosaurs died in the spring.

The researchers analyzed X-rays and carbon isotope records, which showed that fish died within 60 minutes after the Chicxulub meteoroid collided with the Earth. 

For the analysis, the experts focused on the bones of the fish skeletons to examine seasonal growth rings.

“The retrieved growth rings not only captured the life histories of the fishes but also recorded the latest Cretaceous seasonality and thus the season in which the catastrophic extinction occurred,” explained study senior author Jeroen van der Lubbe.

“In all studied fishes, bone cell density and volumes can be traced over multiple years. These were on the rise but had not yet peaked during the year of death,” said study co-author Dennis Voeten.

In particular, the experts examined the diet of a paddlefish, which prefers to feed upon zooplankton. Throughout the year, the abundance of zooplankton fluctuates. 

The study revealed that when the paddlefish died, zooplankton were approaching their summer climax.

“This temporary increase of ingested zooplankton enriched the skeleton of its predator with the heavier 13C carbon isotope relative to the lighter 12C carbon isotope,” explained Suzan Verdegaal-Warmerdam.

“The carbon isotope signal across the growth record of this unfortunate paddlefish confirms that the feeding season had not yet climaxed – death came in spring,” added study lead author Melanie During from Uppsala University.

Video Credit: ESA

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By Chrissy Sexton, Earth.com Staff Writer