Scientific results can help us populate the scene. Ways to identify, compare, analyze, and catalog nature have helped introduce us to the varied and wonderful lives around us and how those organisms are unique in all of history. But the journey we're about to take together requires something more. Even though there is certainly so much more to learn, we have no shortage of papers and tomes trying to boil down and simplify millions upon millions of years of life's history into something we can understand, like the copy of Common Fossil Plants of Western North America sitting on my desk as I write this. But such information is like a smattering of spices and ingredients laid out on the countertop before you start cooking your favorite recipe—those individual parts, even arrayed side by side with each other, don't really feed the curiosity that drives the whole process to start with. Emotion and imagination are the heat that transforms all those parts into visions of the past that have kept people like me picking away at hot stone for generation after generation, not just wanting to see what's left of ancient worlds but desiring connection to times and environments we'll never witness ourselves. Each and every fossil is a touchstone, no matter whether it's a fragment of an ancient leaf or the complete skeleton of a whale, inviting us to consider lives that have come and gone long before us. We may even learn something about what might evolve after we're gone.

Dinosaurs and other charismatic megafauna have often been employed as such inspirations for thinking through time. Such creatures seem so strange and grand that we can't help but wonder about when they lived and why they're not here anymore. If I had found that elusive T. rex along the Montana hillside, the animal's remains would have embodied the fact that the Earth is very old, life has changed through time, and extinction is a reality. The consequences of such finds launched the entire field of paleontology to uncover and understand the nuances of these amazing truths. Even so, the bare facts of life's extremely long history leave us with many more questions. We want to know what these species were like when they were alive, questions about their day-to-day existence that requires placing them within their home habitats to fully imagine. Consider the tree leaves I peeled out of the stone from the tyrannosaur's last resting place, pressed and preserved by the Earth itself. I wonder how the living tyrannosaur would have perceived the trees those leaves belonged to. Did they have a scent, their fruit perhaps emanating a carrion stink to attract dinosaurs, bugs, and mammals to eat them? Did the leaves fall in the autumn? Did they shade great scaly backs in the height of summer? Did they lash back and forth as thunderstorms rolled across the swamps and glades of the Hell Creek ecosystem? Might they have helped the monstrous carnivore conceal itself within the shifting beams of scattered sunlight as it stalked? We know such scenes must have transpired so very long ago, everyday moments when life touched life.

Plants are often the missing part of our paleontological daydreams. For years, I've been concerned with the comings and goings of various prehistoric animals, especially the vast dinosaurian menagerie. Many of the questions paleontologists ask about these animals involve their relationships to each other—who is related to whom, the thrust and parry of attack and defense, and what species comprised the varied dinosaurs that have thrived from pole to pole for more than 235 million years. On expeditions, plant fossils I've stumbled across—in Montana, Utah, New Mexico, Alaska, and elsewhere—have been treated as little more than prehistoric debris, telling us not much beyond the fact that plants once grew here as they do over much of Earth's landmass. Only exceptional botanical fossils seem to merit a note in the field book or collection. The experts I've accompanied have primarily been interested in dinosaurs and other animals, a tree of life determined by the relationships between bones. And yet every time I wondered what the daily existence of those creatures must have been like, the moment would be inscrutable without plants. I started to see fossil plants as more than just filler in the ecological background. Understanding individual plants and habitats opens into broader vistas that span Deep Time, shifting relationships that make our present moment in time all the stranger. The world becomes wilder when you realize that what you perceive around you is the outcome of untold happenstances that flowed one into the next. Life as we know it did not have to exist, and yet it does, the legacy of mass extinctions and the continual unfolding of evolution forming the essential story of why you, I, and the mint bush growing in my front yard are all present in this thin slice of time.

The fossil record not only introduces us to the players and the general arc of the story, but reveals snippets of paleontological dialog where we can draw out interactions both fleeting and formative. Plants and animals have a drama all their own. Animals never would have crawled out of ancient bogs without scaly trees and other plants that altered the terrestrial realm first, thick and otherworldly forests where crunchy insects would eventually entice our fishy ancestors to belly flop onto shore. Gigantic dinosaurs would not have grown to such prodigious sizes without a surplus of green food. Insect life would not be quite so diverse or colorful without plants to pollinate. I had been looking at ancient ecosystems from the top down, following in the steps of charismatic megafauna. I had ignored the flowering of life beneath their feet and that enclosed their worlds—the understory.

Scientific results can help us populate the scene. Ways to identify, compare, analyze, and catalog nature have helped introduce us to the varied and wonderful lives around us and how those organisms are unique in all of history. But the journey we're about to take together requires something more. Even though there is certainly so much more to learn, we have no shortage of papers and tomes trying to boil down and simplify millions upon millions of years of life's history into something we can understand, like the copy of Common Fossil Plants of Western North America sitting on my desk as I write this. But such information is like a smattering of spices and ingredients laid out on the countertop before you start cooking your favorite recipe—those individual parts, even arrayed side by side with each other, don't really feed the curiosity that drives the whole process to start with. Emotion and imagination are the heat that transforms all those parts into visions of the past that have kept people like me picking away at hot stone for generation after generation, not just wanting to see what's left of ancient worlds but desiring connection to times and environments we'll never witness ourselves. Each and every fossil is a touchstone, no matter whether it's a fragment of an ancient leaf or the complete skeleton of a whale, inviting us to consider lives that have come and gone long before us. We may even learn something about what might evolve after we're gone.

Dinosaurs and other charismatic megafauna have often been employed as such inspirations for thinking through time. Such creatures seem so strange and grand that we can't help but wonder about when they lived and why they're not here anymore. If I had found that elusive T. rex along the Montana hillside, the animal's remains would have embodied the fact that the Earth is very old, life has changed through time, and extinction is a reality. The consequences of such finds launched the entire field of paleontology to uncover and understand the nuances of these amazing truths. Even so, the bare facts of life's extremely long history leave us with many more questions. We want to know what these species were like when they were alive, questions about their day-to-day existence that requires placing them within their home habitats to fully imagine. Consider the tree leaves I peeled out of the stone from the tyrannosaur's last resting place, pressed and preserved by the Earth itself. I wonder how the living tyrannosaur would have perceived the trees those leaves belonged to. Did they have a scent, their fruit perhaps emanating a carrion stink to attract dinosaurs, bugs, and mammals to eat them? Did the leaves fall in the autumn? Did they shade great scaly backs in the height of summer? Did they lash back and forth as thunderstorms rolled across the swamps and glades of the Hell Creek ecosystem? Might they have helped the monstrous carnivore conceal itself within the shifting beams of scattered sunlight as it stalked? We know such scenes must have transpired so very long ago, everyday moments when life touched life.

Plants are often the missing part of our paleontological daydreams. For years, I've been concerned with the comings and goings of various prehistoric animals, especially the vast dinosaurian menagerie. Many of the questions paleontologists ask about these animals involve their relationships to each other—who is related to whom, the thrust and parry of attack and defense, and what species comprised the varied dinosaurs that have thrived from pole to pole for more than 235 million years. On expeditions, plant fossils I've stumbled across—in Montana, Utah, New Mexico, Alaska, and elsewhere—have been treated as little more than prehistoric debris, telling us not much beyond the fact that plants once grew here as they do over much of Earth's landmass. Only exceptional botanical fossils seem to merit a note in the field book or collection. The experts I've accompanied have primarily been interested in dinosaurs and other animals, a tree of life determined by the relationships between bones. And yet every time I wondered what the daily existence of those creatures must have been like, the moment would be inscrutable without plants. I started to see fossil plants as more than just filler in the ecological background. Understanding individual plants and habitats opens into broader vistas that span Deep Time, shifting relationships that make our present moment in time all the stranger. The world becomes wilder when you realize that what you perceive around you is the outcome of untold happenstances that flowed one into the next. Life as we know it did not have to exist, and yet it does, the legacy of mass extinctions and the continual unfolding of evolution forming the essential story of why you, I, and the mint bush growing in my front yard are all present in this thin slice of time.

The fossil record not only introduces us to the players and the general arc of the story, but reveals snippets of paleontological dialog where we can draw out interactions both fleeting and formative. Plants and animals have a drama all their own. Animals never would have crawled out of ancient bogs without scaly trees and other plants that altered the terrestrial realm first, thick and otherworldly forests where crunchy insects would eventually entice our fishy ancestors to belly flop onto shore. Gigantic dinosaurs would not have grown to such prodigious sizes without a surplus of green food. Insect life would not be quite so diverse or colorful without plants to pollinate. I had been looking at ancient ecosystems from the top down, following in the steps of charismatic megafauna. I had ignored the flowering of life beneath their feet and that enclosed their worlds—the understory.