Dinosaurs by Rachel Ignotofsky

Dinosaurs aims to present the evolution of life on Earth in an engaging way to young readers. Before embarking on this incredible journey through time, Ignotofsky provides readers with some background information. There are pages that provide explanations of the Geological Time Scale, What Is A Dinosaur?, Understanding Plate Tectonics, Ever Changing Geography, What Is a Fossil?, Reading The Rocks, Mass Extinction Events, and Understanding Evolution. This all sets the stage for exploring life on Earth.

The story begins with the PreCambrian SuperEon, the first four billion years of Earth's history, when the planet formed in the solar system. This period includes the Hadean Ion, the Archean Eon, and the Proterozoic Eon. There are many interesting facts about this time such as during the Hadean Ion the moon was close to fifteen times closer to Earth, during the Archean Ion the oceans were much saltier than they are today, and during the Proterozoic Eon the first mega continent formed. It was during the Proterozoic that the Great Oxygenation Event occured.

Life before the dinosaurs in the Paleozoic Era began to colonize land. The Paleozoic Era has been divided into six geological periods: Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian. The Cambrian saw many new life forms develop. This has been termed the Cambrian Explosion in which creatures with the first backbone, the first lungs and the first legs appeared. The Ordovician saw a huge increase in biodiversification, now termed the Ordovician Biodiversification Event  that saw the development of jawless fishes, tentacled cephalopods and starfishes. The Late Ordovician experienced a mass extinction event, the first of five such events to occur in geological history. The Silurian Period was a relatively quiet time during which fish continued to evolve.

In the Devonian Period much of the Earth's continents covered by warm, shallow seas." It was the age of fishes and coral reefs. A second mass extinction event, the Late Devonian mass extinction occurred but its cause is unknown.  The Carboniferous Period saw swamps and rainforests proliferate. The oxygen content of Earth's atmosphere was also very high at this time as carbon was trapped in the plants and trees. The largest terrestrial invertebrate to ever live, Arthropleura millipede which was eight feet long, inhabited the swamps of the Carboniferous Period.

The Permian Period saw the formation of the giant supercontinent Pangea, surrounded by the global ocean called Panthalassa. Reptiles thrived in the arid, warm interior of the continent. The Permian-Triassic mass extinction event closed out this period.

The Mesozoic Era was the age of the dinosaurs. Three periods have been designated in the Mesozoic: the Triassic, Jurassic and Cretaceous.  The Mesozoic Era began with the worst mass extinction and would end with the devastation of an asteroid impact. Earth had no polar ice caps as the planet was very warm. A day in the Mesozoic Era was twenty-three hours.

The Triassic Period saw the development of a new branch of reptiles - the archosaurs that included the dinosaurs. They were not the large creatures expected but were small. The Jurassic Period saw Pangea begin to break apart due to tectonic activitiy. During this time, it became two separate continents, Laurasia and Gondwana. Rainforests replaced the arid deserts of Pangea, providing a significant source of food for dinosaurs. The Cretacious Period was the climax of the dinosaur's reign. Tyrannosaurus rex the apex predator on land, azhdarchid pterosaurs in the air and Mosasaurus in the oceans. An asteroid impacting the Yucatan Peninsula of Mexico would end their reign.

The beginning of the Cenozoic era, the three main mammal groups were already established. These were the monotremes  (egg-laying mammals), marsupials (mammals that birth live young and carry them with a pouch), and placentals (mammals who give birth to live young from the womb).  During the Cenozoic Era, Earth developed large polar ice caps. There were three periods in the Cenozoic Era: the Paleogene Period, Neogene Period and Quaternary Period.

The Paleogene Period saw large fluctuations in climate. This period was one of mountain building with the creation of the Rocky Mountains and the Himilayan Mountains.

During the Neogene Period the abundance of grasslands saw mammals adapt to running from predators. Early hominids began to evolve to walk upright. The Panama Land Bridge connecting North and South America developed during this time. This land bridge allowed animals and plants to inhabit new areas in what has been called the Great American Biotic Interchange. It also separated the Atlantic and Pacific Oceans, changing ocean currents and weather patterns.

The Quaternanry Period was dominated by multiple ice ages. Animals adapted by becoming large and furry and were known as megafauna. They included mammoths, woolly rhinos and saber-tooth tigers. Modern humans evolved during this period and migrated to all areas of the planet. Humans transformed Earth's ecosystems. 

Finally, the Holocene Epoch which represents the last eleven thousand years of Earth history, is the time in which humans formed civilizations.

Discussion

Dinosaurs is a colourfully illustrated and engaging large picture book that offers a detailed summary of the evolution of life on Earth.  The title is somewhat misleading as the book's focus is more on geological history rather than exclusively on dinosaurs.

After providing some information on important concepts that will be encountered in the book, Ignotofsky launches into descriptions of life during each of the geological eras and their periods. After introducing each period of geologic time life is described in more detail through several features. The Land and Sea provides an overview of each period and there is also a Fun Facts section. For example, in the Devonian Period Fun Facts, the Australian lungfish which has gills and lungs is featured. Each section also has a fascinating "Stories of Discovery" section which highlights various important discoveries relevant to that geologic time period. Some of the features include the Canadian Burgess Shale, and discoveries in the Silurian rocks near the village of Chuanhegai in China, and on Ellesmere island in the high Arctic of Canada. Once the story moves into the Mesozoic Era, life on Earth is divided into two sections, Life on Land, and Air and Sea.

Each geologic period has a Creature Feature which describes some of the life in that period, hopefully based on fossil evidence, although Ignotofsky doesn't specify what is the basis for the descriptions and illustrations. Nevertheless, this makes for a very interesting part of the book.

Overall, Dinosaurs is a very well done, well-written with many interesting facts, colourful illustrations with a well thought-out layout. But there is just so much information, much of it very detailed, that it is questionable as to what age this will appeal to. For younger readers, the visuals will be most appealing, especially the Creature Feature secction, but the large amount of text, most of it in very small font to accomodate the amount of information may feel daunting. Nevertheless, this adult with a background as a geologist found it very appealing!

Book Details:

Dinosaurs by Rachel Ignotofsky

New York: Ten Speed Press    2025

127 pp.

Charles Darwin's On The Origin of Species by Dr. Michael Leach and Dr. Meriel Lland

This oversize nonfiction picture book explores Charles Darwin's theory of evolution and his ideas about the natural world that were published in his book, On The Origin of Species.

In this book, evolution is defined as "the way that living things here on Earth have changed and continue to change." It "explains why there are so many different kinds of plants and animals." This explanation comes from Charles Darwin who described his ideas in his book, On the Origin of Species by Means of Natural Selection, published in 1859. 

This nonfiction picture book sets out to describe how naturalist Charles Darwin came to develop the idea of evolution and natural selection and explain his "big idea".

After identifying some of the great scientific thinkers in the late 1700's and early 1800's, the authors describe the early life of Charles Robert Darwin who was born in 1809. His love of studying the natural world led him to leave the study of medicine and enroll in courses to become an Anglican minister. He obtained the position of a naturalist on the HMS Beagle and journeyed to the Galapagos Islands, off the coast of South America.

 

In 1835, Darwin studied the wildlife on the various islands of the Galapagos, making records and collecting samples. When he returned home to England, Darwin married Emma Wedgwood in January, 1839. They had ten children. Over the next sixteen years, Darwin came to develop a theory as to how species change, by passing on small variations that made them better adapted to their environment. These traits eventually became common to all members of that species. This process was named "natural selection" by Darwin. Another British man, Alfred Russel Wallace also came to have a similar theory and sent his idea to Darwin.

In 1858, their idea of the theory of natural selection was presented at a scientific meeting in London. Wallace admitted that this idea was first Darwin's. This radical idea was very controversial leading to many public debates. Darwin published his theory in a book titled, On the Origin of Species in 1859. In 1871 he further developed his ideas and published a book on the evolution of humans called The Descent of Man, and Selection in Relation to Sex. Because Darwin considered humans as part of the animal kingdom, he believed humans shared a common ancestor with apes.

Darwin continued his thinking and research all his life, writing fourteen books and corresponding with many people regarding his ideas. He died in 1882 and is buried in Westminster Abbey, London.

From this point on, examples of natural selection in action are featured. Other concepts such as "common descent", "survival of the fittest", "the struggle for life", and sexual selection are presented. How island life forms unique organisms, Darwin's tree of life and the interdependence of species are also discussed. The authors also incorporate pages about convergent evolution, the fossil record, the rise of birds, plate tectonics and how this has affected life on Earth, and some of Darwin's ideas that ultimately proved to be wrong.

Discussion

Charles Darwin's On The Origin of Species offers young readers a short biography of Charles Darwin, the British naturalist who posed the theory of evolution and natural selection. Darwin's ideas on how natural selection works to help species adapt better to their environment and his theory of evolution - how life on Earth may have developed over hundreds of millions of years are also discussed.

This book begins by offering some key definitions about evolution, stating that "People and species of plants and animals also change bit by bit over many generations. These processes are gradual and are the basis of evolution - or how living things change over time."  This definition is somewhat vague and doesn't explain what Charles Darwin's theory of evolution has come to embody today. The Merriam-Webster definition is probably more accurate: "the scientific theory explaining the appearance of new species and varieties through the action of various biological mechanisms (as natural selection or genetic mutation)"

It's important for children's science books to strive to be accurate. Darwin brilliantly recognized that living organisms adapt to small changes in their environment so they can better survive. He was able to  describe this with his detailed observations of various animals on the Galapagos. Drs Leach and Lland do an excellent job of presenting this evidence by describing Darwin's finches from the Galapagos and the rainforest frogs in Thailand. 

But Darwin also had another part of his theory which the authors describe as  "Evolution also helps us to understand how groups of animals and plants become extinct, and how new groups emerged - including humans."  In other words, Darwin believed that evolution could explain how new species come about, a process he believed happened gradually, through small changes over a vast period of time. To prove this many, transitional forms must be found to show the development from one species to a completely new one. As Leach and Lland do mention, transitional fossils are not common, making such proof difficult. They present the evolution of whales from a land ancestor  called Indohyus as one example and also the belief today, that birds are the descendants of dinosaurs based on the discovery of dinosaur fossils with feathers, and what is considered an intermediary, Archaeopteryx. 

Leach and Lland also present some of the problems Darwin considered but was unable to solve during his lifetime. One was how plants and animals passed on their characteristics to their offspring. We now know since the discovery of DNA in 1953, that traits are passed on through segments of DNA called genes which are inherited from the parents of an organism. Genes describe protein chains, amino acid by amino acid.  During reproduction DNA is copied but often the duplication is not perfect. These flaws lead to mutations. Most major mutations are fatal, as the work of the German geneticists Christiane Nusslein-Volhard and Eric Wieschaus demonstrated. When Darwin posed evolution, he knew nothing about DNA, amino acids, proteins and inheritance. Had he known, would he have believed that random mutations that occurred early enough in development to affect the body plan of the organism - could drive macro-evolution? Today, many microbiologists and geneticists understand that minor mutations do not create significant evolutionary change as Darwin proposed. And major mutations are usually fatal to an organism. Leach and Lland describe DNA and confidently state that these mutations which they describe as "faults" are what "...create the variants that drive evolution." They do not explore the question that microbiology presents regarding evolution: since genes contain information that is coded in various combinations of the twenty amino acids, where did that biochemical information initially originate? Did the information come from random mutations? Or from some other source? 

The second problem Darwin couldn't solve was "how a species could appear in different places around the Earth." We now know that the Earth is a dynamic system in which the crust is made up of  tectonic plates that are constantly moving. The continents as we currently know them were arranged very differently in the past, into one supercontinent called Gondwana.

One interesting spread in the book is titled The Slow March of Evolution in which Earth's history is presented in the form of a twenty-four hour clock instead of using the geologic time scale such as Cambrian, Ordovician etc . The appearance of different forms of life are assigned a time ( for example, 04.20 First Single Cell Life appears). One issue with Darwin's theory of evolution is how to explain things like the incredible emergence of life at the beginning of the Cambrian Period - known as the "Cambrian explosion." Using the clock instead of the geologic time scale means this "explosion of new life forms" is not as readily apparent.

Charles Darwin's On The Origin of Species offers an overview on the topic of evolution that may encourage young readers to further explore the ideas featured here.  This book could have been made much more engaging with the use of photographs of some of the major characters such as Charles Darwin, Thomas Huxley, and Samuel Wilberforce, photographs of the Galapagos Islands and of the unique animals such as the long nosed horn frog mentioned in the book, as well as the use of maps and the geologic time scale. There is a small glossary at the back which could have been expanded. In addition, there is no information offered on the authors or their credentials. 

Book Details:

Charles Darwin's On The Origin of Species by Dr. Michael Leach and Dr. Meriel Lland

London: Arcturus Publishing Ltd.     2024

64 pp.

Tales of the Prehistoric World: Adventures From the Land of the Dinosaurs by Kallie Moore

For dinosaur aficionados, Tales of the Prehistoric World is book filled with some of the most interesting fossil discoveries over the last two hundred years or so.

Tales of the Prehistoric World opens with information on the Geologic Time Scale which geologists have devised to organize the previous four and half million years of Earth history and brief descriptions of the the five major extinctions that occurred during this time.

Chapter One The Beginning presents a description of two billion years of the PreCambrian when life was just getting started. Moore then quickly moves into the Paleozoic Era in Chapter Two when all of the major animal groups appeared in the Cambrian, around 500 million years ago. Life moved onto land from the ocean and a supercontinent named Pangea also formed. Moore includes the discoveries in the Burgess Shale, a story about the largest trilobite, the age of armored fish, and the appearance of the giant arthropods (insects) of the Carboniferous and Permian.

 

Chapter Three is all about the Age of Reptiles which includes the reign of the dinosaurs during the Jurassic. After explaining the formation of Pangea, Moore highlights the first giant dinosaurs, the sauropods (think Diplodocus and Brachiosaurus) and goes on to describe many interesting and unusual fossil finds, each one increasing our knowledge about dinosaurs. Of course no discussion of dinosaurs would be complete without an entry on Tyrannosaurus Rex. Several famous fossil hunters are also featured including Mary Anning considered  and the rivalry between Othniel Charles Marsh and Edward Drinker Cope. This chapter ends with the currently accepted theory of the cause of the demise of the dinosaurs.

In Chapter Four, Moore explores the post-dinosaur world.The Cenozoic began 66 million years ago and is the Era we currently live in. After the demise of the dinosaurs, with the exception of those who would evolve into birds, the age of mammals. Many other animals grew to enormous sizes such at Titanoboa. Primates evolved and from them our ancestors developed. There were a series of ice ages that changed the way the continents looked.

Discussion

Tales of the Prehistoric World focuses on describing some of the more interesting dinosaur fossil discoveries in the last one hundred and fifty years and how those discoveries have helped scientists piece together the reign of the dinosaurs.

To help younger readers understand where dinosaurs fit into the history of our planet, Kallie Moore, a paleontologist, begins with what geologists and paleontologists believe they know about the beginning of life on Earth. The development of life, from single celled organisms to increasingly more complex ones is presented until the Age of Reptiles in which many different types of dinosaurs and how we came to learn about them are featured. The stories after the demise of the dinosaurs are short and sweet, ending abruptly with the Last Mammoth.

Many unusual dinosaur fossils are featured including a frozen reptile fossil found in Antarctica, unique dinosaurs from prehistoric China, the gemstone dinosaurs of Lightning Ridge in New South Wales, Australia, the remarkable story of the lost and then found again fossils of Spinosaurus, the Egg Mountain site in Montana, the unsolved questions about triceratops, and of course the infamous Tyrannosaurs Rex.

The one drawback to this book is the sometimes uninspiring artwork that accompanies each story. Digitally created, the illustrations at times can be confusing as to what they are attempting to portray. With so many fascinating stories that use many correct terms for various dinosaurs, the illustrations simply aren't up to the same level. For example, one story, The Seafaring Ankylosaur is about the  discovery of an almost complete anklyosaur from the Millenium Mine, a huge oil sand quarry in northern Alberta in March, 2011. Shawn Funk, a heavy-equipment operator was digging in the quarry when he noticed a change in coloration and texture of the rocks. His excavator had already chewed off the tail and back end of the fossil. Funk contacted his supervisor who then reached out to the Royal Tyrrell Museum. When geologists arrived they realized that Funk had discovered the fossil remains of a dinosaur. This fossil specimen was particularly special because it had fossilized features like skin that are normally not preserved. For some reason, Moore doesn't mention the location of this remarkable discovery ( oil sands outside of Fort McMurray) that received much press and the accompanying small map showing the location of the fossil discovery in Northern Alberta is meaningless without any labels. (During the time the ankylosaurus lived, North America was split by a large, inland sea.) Was this just a general oversight or was the location of the discovery in the environmentally contentious oil sands to blame?Because the recovered fossil is so unique, a photograph accompanying this story would have been so much more engaging.

There is also no information about the author, Kallie Moore, except in the introduction to the book where she identifies herself as a paleontologist, nor about the illustrator, Becky Thorns. An online search reveals that Moore is the Fossil Librarian, at the University of Montana. 

Still, readers interested in dinosaurs will find Tales of the Prehistoric a great overview of just how much we've learned about dinosaurs over the past one hundred years.

Book Details:

Tales of the Prehistoric World: Adventures From the Land of the Dinosaurs by Kallie Moore
New York: St. Martin's Press
159 pp.

Prehistoric Dinosaurs, Megalodons, and Other Fascinating Creatures of the Deep Past by Kathleen Weidner Zoehfeld

Prehistoric Dinosaurs takes readers on a journey backwards in time beginning with our own epoch, the Anthropocene.

Readers start with the Holocene epoch which began approximately 10,000 years ago and is the most recent in the Cenozoic era. During this time, humans evolved, the Earth warmed resulting in the retreat of vast ice sheets. This allowed humans to migrate and settle in most parts of the world.

The Pleistocene which began approximately 2.6 million years ago saw the most recent ice age. With climate cooling, ice caps formed at the North and South poles. There were interglacial periods when the climate warmed allowing forests and mammals to flourish. It was a time of saber tooth cats such as Smilodon. Prior to this, during the Neocene epoch (23 million to 2.6 million years ago), mammals began to dominate the Earth.

The Neocene was preceded by the Paleocene which began 66 million years ago. The climate was warm allowing large rain forests to grow and  new types of mammals to evolve. Early primates began living in the trees during this time.

Before the Paleocene, the Cretaceous Period saw the reign of the dinosaurs which were a very diverse group of animals. There were meat-eating dinosaurs such as Tyrannosaurs, as well as plant-eating ones such as Spinops. Flowering plants or angiosperms also developed during the Cretaceous Period providing fruits as a food. In the sea, giant mosasaurs, turtles and ammonites flourished. Scientists have evidence that the Cretaceous experienced a mass extinction even that destroyed seventy percent of the life on Earth. The cause is believed to be an asteroid that crashed in what is now Mexico, resulting in the Earth being overwhelmed with dust and smoke, blotting out the sun. This catastrophic event is believed to be responsible for the demise of the dinosaurs.

It was during the Jurassic, 201-145 million years ago, that the largest land animals developed. These were the sauropods. During this time, the super continent known as Pangea began to break up. This began with the break up of North America from Europe and Asia and later Africa from South America.

About 252 million years ago, the ancestors of dinosaurs and other reptiles were evolving. At this time dinosaurs were small, inhabiting most areas of Pangea.

The Permian period (299- 252 million years ago) saw the formation of the supercontinent called Pangea from the collision two great land masses. At this time there were amphibians, reptiles and pre-mammals. Most were predators who ate other predators.Although there were many plants, they were consumed mostly by insects. The end of the Permian is characterized by a great extinction resulting from an extended period of widespread volcanic activity. It is believed over ninety percent of life on Earth was destroyed.

Before the Permian, the Carboniferous was a time of giant trees and towering ferns. These lush forests were filled with many different arthropods, amphibians and the first reptiles.From 419 to 359 million years ago, the Devonian period saw the development of the first trees and forests, the first insects and spiders and the first four-legged animals such as salamanders.  Prior to the Devonian, during the Silurian (443 to 419 million years ago), temperatures on Earth were slowly rising, allowing new life forms to develop. The first fish with jaws developed allowing predation to occur, as well as the evolution of eurypterids ("scorpion-like arthropods) which could grow to be very large.

In the Ordovician (485 to 443 million years) most life existed in the oceans. Snails, clams, nautiloids, trilobites and conodonts as well the world's first fish lived in the water. This period was characterized by the expansion of coral reefs across the world. The period before the Ordovician is called the Cambrian and this era saw the explosion of life on Earth. This sudden increase in life forms is called the "Cambrian Explosion". Trilobites, a primitive arthropod, dominated the Cambrian period which is sometimes referred to as the "Age of Trilobites".

Finally, the period before the Cambrian is known as the Ediacaran, some 4.6 billion to 541 million years ago. The amazing story of life on Earth began during this time and little is known about the creatures who lived during this phase.


Discussion

In Prehistoric Dinosaurs, Megalodons and Other Fascinating Creatures of the Deep Past, author Zoehfeld has chosen to tell the story of life on Earth beginning with the modern epoch of the Anthropocene (which we are now living in) and moving backwards through time to the very beginning. This makes it difficult to fully understand how life developed from simpler forms to more complex ones, how the climate and the land masses changed over time and how catastrophic events shaped life and the world afterwards. Therefore, it is recommended that readers start at the back of this book and read backwards to the front! Reading in this way works superbly, making the timeline of events more logical and understandable.

Zoehfeld's simple text gives readers a good understanding of the changes that occurred through each period and there are detailed, full colour illustrations which provide a sense of what the Earth may have looked like during each time period as well as the creatures that could be found in the seas and on land. The author includes many interesting facts for each period, and sets aside small areas on each page to explain certain events or to provide more details. For example, there are short, simple explanations of how coal formed, supervolcanoes, how dinosaurs walked, mass extinctions, ice ages and many other topics.

This book was produced in association with the Smithsonian's National Museum of Natural History. A more concise title with a more engaging illustration on the cover is also recommended. Overall, an  interesting presentation of the development of life on Earth. However, the claim on the book's back cover, "What's the best way to see the past? From the present, of course!" didn't work for this reader!

Book Details:

Prehistoric Dinosaurs, Megalodons, and Other Fascinating Creatures of the Deep Past  by Kathleen Weidner Zoehfeld
Greenbelt, Maryland: What on Earth Publishing   2019
45 pp.