YMMV / All Yesterdays

• Awesome Art: Every single illustration in both books. They really sell you on the fact that dinosaurs and their Mesozoic neighbors were animals and not monsters. Special mention goes to the camouflaged plesiosaur, the spiky Triceratops and the beautifully birdlike Microraptor family.
• Genius Bonus:
  • The artwork contains a lot of paleoart references that aren't explicitly stated in the text. The scaly, shrink-wrapped face of the cat, for example, is a Take That! to feathered dinosaurs commonly being portrayed with scaly heads, despite there being hardly any evidence to support this.
  • The restorations of hippopotamus and manatee respectively as a scary hunter and a furry, land-dwelling hervibore by future paleontologists working with their skulls only, are both references to Andrewsarchus, a late Eocene mammal that is known from only one jawless skull found in 1923. Traditionally, Andrewsarchus was interpreted as the largest member of the mesonychids, a lineage of extinct carnivorous ungulates, and the largest land-dwelling carnivorous mammal that ever lived. Since 2009 (All Yesterdays came out in 2012), it's been considered a basal relative of entelodonts and a distant relative of hippopotamuses and whales instead. As for the manatee, there was once a hypothesis (though informal and never published) that Andrewsarchus was an early whale similar to Ambulocetus, but bigger and that lived in freshwater.
• Genre Turning Point: Before this book's release there was an unspoken rule in the Paleoart community to follow the norms of past depictions of animals, even if a large portion of it was just speculation. This book inspired many paleo artists to speculate a lot more with their depictions of prehistoric life.
• It's Short, So It Sucks!: While the book is generally well received, the main complaint even from people who liked it is that it's a lot shorter and has less content than they expected.
• Misaimed Fandom: As Mark Witton pointed out in The Palaeoartist's Handbook, the purpose of All Yesterdays was to fill in missing gaps in the fossil record, be less conservative in paleoart, and look at common modern animal behavior to speculate similar behavior for extinct animals. However, many paleontology fans have taken the book's message to mean "anything goes", and thus depict extinct animals with all sorts of crazy features or behavior that is ill-supported at best and downright contradicts both the fossil record and modern animal biology at worst.
• Nightmare Fuel: Several instances, including the Stegosaurus raping an unfortunate sauropod (yes, you read that correctly), the pterosaur-eating centipede and practically every installment of "All Todays" (especially the spider monkey).
• Sequelitis: All Your Yesterdays was significantly less well-received than the original. This may have something to do with a large portion being contributions from non-experts. Despite this, three of its speculations (that some anomalocaridids fed like modern baleen whales, pterosaurs diving for fish and scansoriopterygids gliding like flying squirrels) were actually confirmed by subsequent fossil discoveries.
• Spiritual Successor:
  • The Cryptozoologicon, by the same authors, a book on various legendary beasts such as Bigfoot, Sasquatch, and Yeti and El Chupacabra where they speculate on what their biology and evolutionary history might be like if they were real.
  • Prehistoric Planet, which features Naish as a consultant, shows Mesozoic animals in colorful, mostly non-violent situations, sometimes with behaviors and soft tissues based on modern animals for which there is little evidence for but also no evidence against. In particular, the speculative Carnotaurus and Elasmosaurus mating rituals from the book are almost adapted straight into the show.
• Squick:
  • Homo diluvii, seen in bottom left picture in this compilation of pictures◊ from All Yesterdays. It is humanoid in a rather disturbing way.
  • The giant penises of the Citipati and Stegosaurus.
• What Do You Mean, It's Not for Kids?: It's got large, clear text and brightly-colored illustrations, and for the most part is perfectly appropriate for young dinosaur fans... except for the aforementioned picture of the Stegosaurus.

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