'NOVA: Rise of the Mammals'
(DVD / PG / 2020 / PBS)
Overview: An asteroid blasted Earth 66 million years ago, wiping out the dinosaurs. How did life recover?
Now a massive discovery a trove of fossils from the key first million years after the cataclysm tells the story.
With exclusive access, this documentary recounts a rare find of animals, plants, and precise dates. Together, they reveal how a new living world one that came to include us rose from the ashes.
DVD Verdict: Watching this enthralling new documentary from PBS, we learn that life came back surprisingly quickly to the site of the impact that killed the dinosaurs.
When a 6-mile (10 kilometers) asteroid slammed into the Gulf of Mexico 66 million years ago, causing the demise of the dinosaurs as part of the largest mass extinction event in the last 100 million years, it took life on the planet at least 30,000 years to bounce back.
The space rock also melted the crust and mantle at the point of impact, making modern scientists suspect that life would have had a particularly challenging time recovering at that location.
Yet a core sample from the crater rim has revealed that, even at ground zero, life managed to bounce back rapidly, closely matching the resurgence of life around the globe.
Beneath the tropical Gulf of Mexico, near the Yucatan Peninsula, lurks the crater known as Chicxulub. This indent in the Earth is the tombstone of the rock most famous for killing off the dinosaurs.
The asteroid impact also triggered acid rain and forest fires around the globe, and blasted sulfur and other rock into the air in quantities large enough to block the sun.
The collision vaporized the kamikaze asteroid and put a significant dent in the number of species alive on Earth. It also scattered the dust around the world to create what scientists call the K-T boundary, a layer that includes bits of the asteroid itself sandwiched between the rock layers that formed before and after.
However, these traces of the asteroid alone weren't convincing enough to attribute the extinction to the space rock's collision with Earth. Then, in the late 1970s, geophysicists searching for petroleum found the 110-mile-wide (180 km) crater beneath the ocean.
It took more than a decade to find a substantial link between that crater and the mass extinction that killed the dinosaurs.
In 2016, a team of scientists headed to the gulf to take a core sample from the crater rim. Drilling into the ocean floor from a ship on the surface, they excavated a half-mile-long (800 meters), pillar-like core that revealed the geologic history of the region.
The task required specialized drilling equipment, but the challenge paid off: The underwater location managed to preserve the crater far more than happens with land-based craters.
Its subsurface placement makes Chicxulub "the most well-preserved crater" known to date, said David Kring, an impact petrologist on the excavation team who has studied the crater for decades.
The extinction event at the end of the Mesozoic era caused by the asteroid is the only such event to have occurred suddenly, thanks to its external origin.
According to some of the people who are interviewed here, other massive extinctions occurred gradually, caused by volcanic events and climate change. Under those circumstances, other life-forms filled the niches cleared by their doomed neighbors.
But when the asteroid slammed into the Earth, it almost immediately created a 150-km-wide (90 miles) sterile region where no life could survive. Measurements of the seafloor taken in the 1970s revealed this dead zone, Lowery said, though its source was then unknown.
There is oh-so much more to be discovered about this event and how we got our "life" back together again thereafter, so come check it all out in the truly eye-opening 'NOVA: Rise of the Mammals' from PBS! This is a Widescreen Presentation (1.78:1) enhanced for 16x9 TVs and it comes with the Bonus Videos of:
Concretions: Fossils In Plain Sight
Paleontologist On The Bluffs
A Paleobotanist's Dream