The Last Days of the Dinosaurs: Planet Earth’s Terrible, Horrible, No Good, Very Bad Day

The Last Days of the Dinosaurs by Riley Black

As just about any child can tell you, roughly 65 million years ago a nearly ten-mile-wide asteroid crashed into the earth in the Yucatan, unleashing planet-wide firestorms, geography-changing tsunamis, and years of acid-rain and dark days. In short, it was not a good day for Planet Earth. Or for the more than 75% of animal species wiped out by the impact, including, of course, its most famous victims, the dinosaurs. In The Last Days of the Dinosaurs (2022), Riley Black gives a wonderfully evocative and vivid accounting not just of those horrible days following the asteroid’s impact, but of life’s slow recovery during the following million years, making the book, in Black’s words, not a “monument to loss [but] an ode to resilience.”

Her particular focus is on the Hell Creek area of the western US as it is one of the most explored sites as well as one of the most plentiful when it comes to fossils, but Black ranges widely both in place and time, offering up a truly global perspective on the disaster. And as noted, does so in vivid prose — a rich, vibrant evocation of setting and species that reads more narrative than informational, as in this passage:

All is calm on this morning. The sun is still low, casting golden light over the marshes and strands of trees. The rex continues her aimless patrol … Insects stridulate and sing from the trees. Crocodiles and odd croclike copycats called champsosaurs snap at fish and small turtles in the weed-choked swamps. Fuzzy mammals chitter at each other from their burrows and tree branches … Every morning begins with a chorus of birds and pterosaurs all talking to members of their own species … As the midmorning sun begins to erase the long shadows of morning, the rex steps through a strand of dawn redwoods growing by a small pond and dips her head down to drink.

Chapters are chronologically arranged, with increasing gaps of time between them:

Riley Black

• Before Impact
• Impact
• The First Hour
• The First Day
• The First Month
• One Year After Impact
• One Hundred Years After
• One Thousand Years After
• One Million Years After

Each chapter has a brief addition that shifts the gaze from Hell’s Creek to other areas and ecosystems such as eastern Utah, the North Atlantic, Antarctica, India, and New Zealand. The level of detail is both precise and plentiful, as for instance when Black discusses how it wasn’t simply the size of the asteroid that created such massive destruction but the combination of variable such as its speed, the angle it struck at, and where it struck.

While some of what Black covers is by nature going to be speculative — “inferred from hypotheses and available evidence” — most of it is based solidly in fact. For those wondering which is which, Black includes an appendix “explain[ing]what’s fact and what’s hypothesis or invention.”

She also adds a conclusion which brings a welcome personal touch to the tale, touching on a hike to see the iridium layer (the “smoking gun” for the asteroid impact theory), the way she cannot fully explain “why I ache for these creatures the way I do,” how “the years I’ve spent as a transgender woman have affected my perspective.”

One of my favorite aspects of this overall excellent work of non-fiction is how Black doesn’t simply focus on the dinosaurs, or even on other species such as birds or mammals (though she does of course cover both), but takes a more holistic view, examining the complex interweavings of entire eco-systems. The animals yes, but also the insects, the plants the climate, etc.

Always engaging, sometimes lyrical, at all times compellingly informative, The Last Days of the Dinosaurs is a stellar example of non-fiction writing at its best. When Black closes the narrative section by noting that “life, resilient and strange, continued, the beginning of another day in the new Age of Mammals,” I found myself picturing a sequel to this book: “The Continuing Days of the Mammals.” Here’s hoping . . .