Marine reptiles called Ichthyosaurs existed millions of years ago within a vast ocean that surrounded the supercontinent known as Pangea. They had streamlined bodies adapted for swift movement in aquatic environments.

The Species from Feces Lab at Northern Arizona University examines DNA in animal feces. The lab’s motto is "to be number one at number two.”

Fewer than 2% of North America’s bark beetle species attack trees, but those that do have killed billions of conifers across the West over the last 30 years.

All kinds of animals use conspicuous colors. Research from biologists at the University of Arizona found it's a quirk of evolution that started around 150 million years ago.

The Mojave Trail was initially used by Indigenous tribes for trade and travel but later became a critical route for Spanish missionaries, American settlers and military expeditions.

Though distinct disciplines, both paleontology and archaeology use similar technologies and methods in their work and show fascinating intersections.

Spring mounds are found in arid regions worldwide where geological formations force groundwater to the surface. In the U.S., the feature is especially common in the mineral-rich soils of the Great Basin and Mojave Deserts.

Arizona is home to over 1,000 volcanoes and has three active volcanic fields, the largest of which is the San Francisco Volcanic Field near Flagstaff.

Waking on winter solstice to a hushed world of bright light, we look outside and see fresh-fallen snow.

The original Christmas Bird Count involved 27 birders, who tallied up 90 species on Christmas Day. More than a century later, the survey continues in what may be the world’s longest-running community science project.