Ancient penguin was as big as a (human) Pittsburgh Penguin
Fossils from New Zealand have revealed a giant penguin that was about the size of a grown man
Los Angeles subway work uncovers array of Ice Age fossils
Since crews began work to extend a Los Angeles subway line in 2014, they have routinely turned up the fossilized remains of rabbits, camels, bison and other creatures that roamed the region during the last Ice Age.
Subway paleontology: LA construction unearths fossil trove
The Los Angeles subway system is expanding, and so too are the number of prehistoric fossils being recovered as crews dig beneath the city
10 Things to Know for Monday
Among 10 Things to Know: Who lays low in Alabama election run; Where sexual harassment comes with the job
Officials: Whales , after deadly year, could become extinct
Officials with the federal government say it's time to consider the possibility that endangered right whales could become extinct unless new steps are taken to protect them
Polar bears, Alaskan villagers way of life at risk, experts say: Part 2
Climate change experts are studying polar bears who arrive in Kaktovik, Alaska to see how climate change has impacted the ecosystem.
Polar bears descend on Alaskan village, causing tourist boom: Part 1
Visitors flock to Kaktovik, Alaska, to see the bears, who are wandering into town because experts say the sea ice they need is disappearing.
Alaskan town's polar bear problem leads to tourism boom
Polar bears are an enduring symbol of the wild arctic, a mighty beast that has made its home in punishing terrains. But in recent years, the polar bear has come to embody something else: A creature caught in a world that’s disappearing under its feet. Each fall, the bears descend in hordes on the
Dog sledding, another sport facing doping scandals, abuse allegations
The controversial documentary "Sled Dogs" claims to show dog neglect and abuse is common practice, but many in the dog sledding community say the film is flawed.
8 things you never knew about the Christmas movie 'Elf'
It’s been 14 years since “Elf” hit theaters as an instant Christmas classic, and for director Jon Favreau , fulfilling that goal was his “greatest joy.” Aside from the jokes, the singing, the nostalgia and the quotable scenes, Favreau and producer Peter Billingsley spoke with "20/20" about some of