Topic: Biology

Scientists discovered a new species of tiny mammal that lived during the time of dinosaurs. This mammal was part of a group called multituberculates, which survived for over 100 million years before going extinct.

The world was once home to both mammals and dinosaurs. But about 75% of all life on Earth disappeared in an event known as the mass extinction that occurred 66 million years ago. Some species managed to survive this catastrophe. Among them were small, rodent-like mammals belonging to the genus Cimolodon. These animals were part of the multituberculates group, which first appeared during the Jurassic Period and persisted for over 100 million years before eventually going extinct.

A team led by researchers at the University of Washington has identified a new species within this genus based on a fossil found in Baja California. The fossil is estimated to be around 75 million years old. The newly named species, Cimolodon desosai, was roughly the size of a golden hamster.

The team used digital imaging and micro-computed tomography (micro-CT) to analyze the fossil. They compared the teeth of C. desosai with those of related species in the Cimolodon genus to confirm it was distinct.

This new species, Cimolodon desosai, was ancestral to the species that survived the extinction event. It and its descendants were relatively small and omnivorous -- two traits that were advantageous for surviving.

Why It Matters

Understanding how early mammals like this tiny mammal survived the mass extinction can help us better understand how life on Earth has changed over time. This knowledge can also inform our decisions about conservation and protecting endangered species today.

Key Facts

• The new species, Cimolodon desosai, was a small, rodent-like mammal that lived around 75 million years ago.
• This species was part of the multituberculates group, which survived for over 100 million years before going extinct.
• The fossil was found in Baja California and is estimated to be around 75 million years old.
• The team used digital imaging and micro-computed tomography (micro-CT) to analyze the fossil.
• This new species was ancestral to the species that survived the extinction event.

Key Terms

Mass extinction

A catastrophic event in which a large percentage of all life on Earth disappeared.

Implications

Understanding how early mammals like this tiny mammal survived the mass extinction can help us better understand how life on Earth has changed over time. This knowledge can also inform our decisions about conservation and protecting endangered species today.