Vote: What Would You Name Squirrelly Mammal Ancestor?

hypothetical mammal ancestor — An artist's rendering of the hypothetical placental ancestor, a small, insect-eating animal with a long, furry tail. The research team reconstructed the anatomy of the animal by mapping traits onto the evolutionary tree most strongly supported by the combined phenomic (physical traits you can see) and genomic data and comparing the features in placental mammals with those seen in their closest relatives.

(Image credit: Image courtesy of Carl Buell)

What do you name the ancestor of almost all living mammals?

According to LiveScience readers, "Ralph" wouldn't be a bad bet.

Latest Videos From

It may seem odd to announce the discovery of an animal that never existed. But the origins of placental mammals — mammals that nourish their young in utero via the placenta, which accounts for nearly all living species — are foggy. The fossil record suggests that mammal diversity exploded after the dinosaurs died out about 65 million years ago at the end of the Cretaceous period, but genetic studies indicate a longer evolution for mammals dating back before the end of the Cretaceous.

The goal of the ancestral mammal project was to marry fossil and genetic evidence, piecing together the DNA and physical changes to trace the lineage back to the beginning, or at least an approximation of the beginning. The result was an insect-eating four-legged creature that weighed less than half a pound. From these humble beginnings arose everything from elephants to bats. The researchers reported their findings on Feb. 8 in the journal Science. [6 Strange 'New' Species Hiding in Museums]

Stephanie Pappas is a contributing writer for Live Science, covering topics ranging from geoscience to archaeology to the human brain and behavior. She was previously a senior writer for Live Science but is now a freelancer based in Denver, Colorado, and regularly contributes to Scientific American and The Monitor, the monthly magazine of the American Psychological Association. Stephanie received a bachelor's degree in psychology from the University of South Carolina and a graduate certificate in science communication from the University of California, Santa Cruz.