Dinosaur Age Estimates Challenged by New Crocodile Findings

Determining the age of extinct animals—particularly ancient creatures like dinosaurs—has long been a complex scientific challenge. Researchers typically rely on clues embedded within bone structures. However, recent findings suggest that the accuracy of methods commonly used to estimate dinosaur ages may require to be reevaluated.

A new study focusing on crocodiles reveals that these reptiles can experience multiple growth cycles within a single year. This discovery is significant given that crocodiles are close relatives of dinosaurs. If a similar pattern existed in dinosaurs, some current estimates of dinosaur ages could be inaccurate.

How Scientists Determine Animal Age from Bones

In biology and paleontology—the study of ancient life—several techniques are employed to estimate the age of skeletal remains.

One approach involves examining the degree of suture closure in bones, assessing how far the plates of bone have fused as the animal grows. Another method analyzes the texture of the bone’s surface.

However, the most widely used technique involves studying growth marks on the microscopic structures within bones. This method is known as skeletochronology.

Most modern animals do not grow at a consistent rate throughout the year. They typically experience periods of rapid growth during favorable seasons—for example, when food is abundant, temperatures are ideal, and water is readily available. Growth slows during less favorable times.

These periods of slowed growth leave traces on the bone, similar to the rings found in tree trunks. By counting these marks, scientists can estimate an animal’s age.

For years, research has focused on determining when these growth cycles occur and how this method can be applied to age animals.

The Importance of This Method in Dinosaur Studies

Skeletochronology is crucial in the study of ancient reptiles, including dinosaurs.

The technique helps scientists construct growth charts for dinosaurs over time and compare growth rates among different species. This information is vital for understanding how these ancient animals reached enormous sizes.

However, new research indicates that this method may have limitations.

Surprising Discoveries in Crocodile Relatives

Researchers at a paleobiological laboratory at the University of Cape Town made an unexpected discovery while studying young caimans—reptiles closely related to crocodiles and alligators.

In animals less than one year vintage, researchers already found growth marks on their bones.