I got this book a year ago and am so happy I finally got around to reading it as I really enjoyed it. It focuses on paleontological art and looks into how the common perception of how dinosaurs look could differ as there is only so much we can know about skin, musculature, fat, feathers, etc. The book briefly explains what we know of certain dinosaurs and how we picture them and then offers a speculative view of how they might actually be quite different from what we have imagined. When dealing with fossils there is only so much we can determine and a lot of the reconstruction is speculative and guess-work. The second half of the book explores present-day animals and how they might look to someone that had never seen them, based solely on the skeletal structure. It was very interesting to see how currently existing animals could be pictured if extinct and amazing to see how different they could be assumed to look from their fossils alone. It really made me wonder how different dinosaurs might look from what we have always imagined. I really enjoyed the artwork in this book also, as it ranged from artistic to adorable representations. All Yesterdays is easy to understand even for those who might not know much about dinosaurs or paleontology. I highly recommend this book. It is interesting, funny, and really makes you stop and think about how different the world of the past might have looked.