Paleobiologist Thomas Halliday takes us on a journey through the history of our planet and the unrecognizable worlds that once shaped and sustained life on Earth.

We know that planet Earth is an ancient entity. We've seen fossils and rocks that date back millions of years, and can picture dinosaurs roaming the earth.

But Earth has changed so much over the millennia that the worlds these animals inhabited were very different from our own.

In his 2022 book, Otherlands, paleobiologist and author Thomas Halliday explores the worlds that once existed on Earth.

From the beginnings of our planet to the era we know and live in, Halliday walks us through the changing temperature, flora, and fauna that developed, grew, and expired on Earth, and asks how much we are impacting our planet's environment today.