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I have been working on lectures on early amniote evolution, along with the following reptilomorph and synapsid lectures for my vertebrate paleontology course. We will be getting into dinosaurs and the other Mesozoic animals very soon, hooray! However, in preparing these talks, it has brought to my attention just how prevalent two sites in particular are: Reptileevolution.com and Pteresaurheresies.wordpress.com.
When I did a search for “pterosaur”, Google actually responded by saying “Did you mean pterosaur heresies” and provided images that all but one are either from the site or sites complaining about the site.
This is quite unfortunate. Both sites present an abundance of beautiful artwork done by a stellar paleoartist. There is an abundance of information on the animals and their relationships. All in all, the websites look fantastic and are quite the draw for paleo-enthusiasts.
But it is all wrong.
None of the hypotheses presented on these pages is accepted by virtually any other paleontologist. The techniques used to gather the information is not considered valid and no one who has tried to reproduce the data using the methods have had any success.
I won’t get into details about why the websites are wrong. I am frankly not qualified enough to provide a step-by-step breakdown of the problems (not being an expert in either pterosaurs or basal tetrapods), nor do I really have the time. I will say that many years ago, I heard the author of these websites give a talk about his evidence for a vampiric pterosaur and even as a young undergraduate, it was clear to me that neither the technique nor the conclusions were valid. I found it very unfortunate because the idea of a vampiric pterosaur was incredibly cool and the technique, which involves detailed image study, is useful in many contexts. However, it is very easy to let personal biases enter into conclusion based on these methods, to allow oneself to extrapolate well beyond anything the data can actually support. Oftentimes, those biases are completely unknown to the observer simply due to the way our brains interpret sensory input and modifies them based on past experience. We really do not see everything we think we see, which is why the scientific method requires other scientists examining your conclusions and your methods and trying to poke holes in your ideas. So it is vital to recheck one’s conclusions with many detailed images from various angles and lighting methods and, most importantly, detailed examination of the fossil itself.
So instead, I will point you to articles written by people who are experts in the very animals that are discussed on those pages and what they have to say about them. The first is an article by Dr. Christopher Bennett, who is an expert on pterosaurs. In this article, he discusses the validity of the techniques and discusses specific claims of two pterosaurs in particular, Anurognathus and Pterodactylus. Anurognathus is a very odd-looking pterosaur and is quite aptly named “frog mouth.” Pterodactylus is probably the most famous pterosaur next to Pteranodon and is why so many people mistakenly refer to all pterosaurs as pterodactyls. Dr. Bennett does an excellent job critiquing the science in a professional and readable way.
The second article is a blog post by Darren Naish, a noted researcher and science author that has researched pterosaurs and many other animals who has a deep understanding of both the accepted science and the author of these websites and the work presented therein. Here is what he says: “ReptileEvolution.com does not represent a trustworthy source that people should consult or rely on.Students, amateur researchers and the lay public should be strongly advised to avoid or ignore it.” The emphasis is completely his. The post is quite long and discusses several aspects of the work, discussing the accepted science and the material on the websites that is not accurate, including the techniques used to arrive at the conclusions, both accepted techniques and those by the website author that are not.
The next site is an article by Pterosaur.net, a website devoted to research on pterosaurs by pterosaur researchers. It is a brief article that uses Naish’s article as a starting point and continues on with a discussion of why they think it important for people to know why these sites should be avoided. To quote: “The issue taken with ReptileEvolution.com is not that it exists, but that it’s internet presence has grown to the point that it is now a top-listed site for many palaeo-based searches. Tap virtually any Mesozoic reptile species into Google and either ReptileEvolution.com or the Pterosaur Heresies is likely to be in the first few hits. The situation is even worse for image searches, which are increasingly dominated by the many graphics that Peters’ uses on his sites.” This would not be a problem that the sites are so well known if they were correct, but their prevalence presents a highly flawed version of what scientists really think. People are taking these sites as truth, when in fact they are regarded by professionals as seriously wrong.
Finally, Brian Switek, a science writer who authors the blog Laelaps, which moved from Wired Science Blogs to National Geographic and the now-defunct blog Dinosaur Tracking for the Smithsonian, wrote a piece on the site, in which he urged more paleontologists and paleontology blogs to call out misleading websites like these. In that spirit, I hope I can help some avoid getting a mistaken impression of dinosaur science and help steer them to better, more reliable sources.
* If you are wondering why I say “the author” or “the artist” rather than using the person’s name, it is because I don’t want this to be about the person, but the information. I don’t personally know the author, nor have I ever had direct contact, so I have nothing to say about the person. The work, however, can be and should be open for criticism, just like any other researcher, including my own.
Last Friday I posted clues to a mystery fossil. The clues were 1) I lived in AR during the Mississippian Period roughly 330 million years ago and am a very common fossil to find here. 2) Many people think I’m a coral, but I’m not. 3) I am named after a famous Greek mathematician and inventor. Who, or more precisely, what am I? Allie Valtakis got the right answer as the bryozoan, Archimedes. Here is what the Arkansas Geological Survey says about it.
The Bryozoa grow attached to the sea-floor as do corals, but they differ significantly from corals in terms of soft-part anatomy. The bryozoans are exclusively colonial and fall into two broad groups, the lacy colonies and the twig-shaped colonies. Individual “houses” (zooeciums) lack the radial partitions found in corals, but they are divided transversely by partitions called diaphragms (Fossils of Arkansas). Bryozoans can also grow as incrustations on the shells of other organisms and are commonly associated with reef structures.
“Bryozoans are tiny colonial marine animals that are present in marine and fresh water today. They are sessile benthonic animals (fixed to seabed) that are filter feeders and prefer shallow seas, living fairly close to shore (neritic). One bryozoan called Archimedes (see picture below) is abundant in Mississippian age rocks in Arkansas and is so plentiful that one of the rock formations called the Pitkin Limestone was once referred to as the “Archimedes Limestone”. Generally, only small pieces of bryozoans that resemble “fronds” are preserved in Mississippian and Pennsylvanian age rocks in the Ozark Plateaus Region.
Freeman, Tom, 1966, Fossils of Arkansas: Arkansas Geological Commission
Bulletin 22, 53 p., 12 pls., 15 figs., 1 map.
Way to go, Allie!
Can you guess this week’s fossil? I will do things a bit differently this time. Unlike previous fossils, in which I told people on the Facebook page as soon as someone provided the correct answer, I will not reveal the answer until Friday, so you have plenty of time to give it a try. In addition to the picture (note the scale) below, I will provide one clue every day until Friday. Good luck!
Clue 1: It’s from the Cretaceous.
Clue 2: It’s modern day relatives are widely considered a delicacy.
Clue 3: This is no wilting lily. This creature is big and bold. It shows how twisted it is on the outside for all the world to see. Dude, that’s heavy.
Come back tomorrow for the answer! You can also find it on the Facebook page.
Walking with Dinosaurs 3D movie review
I went to see Walking With Dinosaurs 3D this weekend. My kids were interested in seeing the movie and I liked the BBC “Walking with Dinosaurs” TV mini-series, so we were all eagerly anticipating the movie. I had read a few reviews of the movie, some by paleo people, who said the dinosaurs were great, but the voices were terrible, which gave me pause, but it’s a BBC movie on dinosaurs, how bad could it be, right?
Sad to say, I have to agree with most of the reviewers. This movie may be much more enjoyable if you can’t hear it. To begin with, whatever expectations you may have, forget them. If you are going in expecting to see a big screen version of the BBC “Walking with Dinosaurs,” you will be disappointed by the cartoon voices and plot. If you are looking for light entertainment for little kids, you might be a bit surprised by the rather jarring breaks providing a subpar, documentary-style educational interlude which will kick everyone out of the story.
The film reminded me nothing so much as a cross between the BBC documentary-style series and The Land Before Time movie series, failing at both. I think the reason for this is because it seemed to clearly start off with the idea of it being a kid-friendly movie along the lines of the TV series, but some executive decided after it was made that it was not going to draw enough kids. So the movie was recut and really bad dialogue added to it instead of the normal narration one would expect in a nature documentary, along with completely superfluous modern scenes bookending the film, wasting the talents of otherwise fine actors. The voices were obviously added as an afterthought because the dinosaurs do not act like they are speaking. I could even occasionally hear the original dinosaurian bleating and honking in the background even as they are supposedly talking. The dialogue, as Brian Switek noted in his review, destroyed any emotion that may have been evoked by the scenes that were supposed to be emotionally powerful. What should have been poignant, heart-tugging scenes were drained of any impact by juvenile pratterings that never ceased. I found myself wishing for the dinosaurs to just shut up once in a while. As a result, it is a movie that may be enjoyable for a little kid, but eminently forgettable. Bambi was a much more riveting emotional experience, not to mention more educational about the lives of deer.
The story line was inconsistent with the idea of a nature documentary and a poor choice for a dinosaur movie. Whether or not the worst aspects of it were in the original script, I don’t know, but the final plot, while suitable for a cartoon Land Before Time, was wholly inappropriate for a nature “fauxmentary.” For a film that was supposedly educational, it pushed moral viewpoints which are only valid in human cultural environments and completely invalid in the natural world. The idea that intelligence and courage will overcome the thoughtless, testosterone-fueled belligerence of the larger alpha males is a noble sentiment and may work in a human context, but not in the depicted dinosaur society. Control of a herd of large herbivores that have evolved extravagant displays will never pass to the runt of a litter because he saves the herd in a time crisis due to his quick thinking. The plot line for the movie is far more appropriate to an after-school special involving actual, human children, not dinosaurs. As such, it completely destroys any educational effectiveness of the movie. The only education that remains is that dinosaurs lived in a snowy Alaska and that some dinosaurs had feathers, particularly the smaller theropod carnivores. I really like this aspect of the movie, but its authenticity in these aspects was completely undermined by the silliness of the rest of the movie.
To make it even more confusing in terms of genre plotting, the movie shows that females in the herd are dominated by the alpha male, but glosses over what that means in terms of sexual dominance. In a kid-based movie, this understandably only goes as far as hanging out with each other. In the natural world (and post-adolescent human worlds), as every adult in the audience will understand, it means the female submits to the alpha male’s sexual advances. In terms of a human kid’s movie, it sends very poor messages about the role of females in society. In terms of an educational nature show, it is intentionally misleading to spare the typical parental sensibilities of what is appropriate for kids to see.
In short, if you go to see this movie (which I would really recommend waiting until a rental, as it is not worth spending the price for a 3D movie), go expecting to see a mindless 80 minutes of passable, but forgettable, entertainment for children with no real educational value other than to say look, aren’t dinosaurs neat? Enjoy the graphics, ignore the rest.
The Big Golden Book of Dinosaurs
By Dr. Robert T. Bakker
Ilustrated by Luis V. Rey
Publication date: 2013. 61 pg.
Golden Books, Randomhouse. ISBN: 978-0-375-96679-8.
Do these books look familiar? One is the classic book that most people old enough to be parents grew up on, first published in 1960 and continuing through 1981. The second is the new, Big Golden Book of Dinosaurs, a new, totally updated edition that came out in 2013. The book is written by Dr. Robert Bakker, known by many as the bushy-bearded, cowboy hat-wearing paleontologist of many documentaries and the author of such books as the Dinosaur Heresies and Raptor Red. Illustrations are by Luis Rey, a talented artist already mentioned here due to his work illustrating Dr. Holtz’s Dinosaurs book. Dr.Holtz’s book was written for a wide audience, geared towards children of middle school age and upwards. This book, like its predecessor, is geared for elementary kids. So it is not as detailed, but it is even more lavishly illustrated and will definitely hold the interest of younger kids.
From the front cover to the last page, those who know and love the original book, will find it echoed here, but updated with the latest information. inside the front cover is a map of the world as it existed in the Triassic and early Jurassic, with dinosaurs dotting the landscape, showing where various dinosaurs have been found. The map is matched on the inside of the back cover with a Cretaceous map. Both maps have the names of each of the dinosaurs illustrated so you know what you are looking at. There is also an index and handy pronunciation guide for all the animal names.
While the book is of course heavily weighted towards dinosaurs, like the previous book, it does not focus entirely upon them. In the brief introduction, it makes a point to place the dinosaurs in context as part of an evolving ecosystem, not as isolated creatures. The book then dives into the Devonian seas,introducing us to the fish that began the walk towards becoming landlubbing tetrapods (animals with four legs). It continues with a few pages on the Carboniferous and Permian Periods, with giant insects, early amphibians and reptiles, and even animals like the iconic Dimetrodon, properly identifying its kin as ancestral to modern mammals, even explaining key features showing it’s related to us. Only then do we get to the Triassic, the beginning of the Age of Dinosaurs and even then, it starts the discussion with pterosaurs and the ancestors of crocodylians. After a mention of the earliest dinosaurs, it then mentions the proto-mammals.
Finally, we reach the Jurassic Period and it is here that dinosaurs take center stage, with gigantic, long-necked sauropods and other well-known dinosaurs. Even so, they don’t forget the small, mouse-like early mammals under foot. After a brief interlude to discuss the great sea reptiles that appeared during this time, as well as the pterosaurs, that were now much bigger and diverse than in the Triassic, they return to a discussion of dinosaurs, this time focusing on a bit of history explaining how our views have changed over the decades.
The book moves then into the Cretaceous, showing how dinosaurs adapted to diverse environments, such as the sand dunes of central Asia to the snows of the poles. There is a chapter on different ways dinosaurs communicated with each other, including singing, after a fashion, much like birds and animals call to each other today, although he goes a bit overboard in this area and speculates beyond what most in the field would say is reasonable. Of course, no elementary book would be complete without a chapter devoted to Tyrannosaurus rex and its battle with an armored herbivore, in this case, the ankylosaurid Euoplocephalus and a battle with Triceratops. While the book makes much of the use of horns and frill by the Triceratops in battling T. rex, they were almost assuredly evolved to battle other Triceratops as dominance displays, like bison or antelope today, although that of course, doesn’t rule out their use as defensive weaponry against predators.
There is the required chapter on dinosaur extinction and it does a good job of mentioning several possibilities. However, it gives a bit of short shrift to the most accepted asteroid hypothesis and a bit more space to Bakker’s favorite hypothesis of disease, which is almost assuredly not true as a hypothesis of widespread extinctions on such a large scale. To his credit, he ends with the likely possibility that no one hypothesis is sufficient for explaining everything.
The book ends with what animals actually benefited from the extinction, that being mammals. The book ends with noting that not all dinosaurs died out and acknowledging the influence that dinosaurs had on the evolution of early mammals, thereby connecting the story of the dinosaurs to us. Besides the great illustrations, that I think, is the key strength of this book, never letting the reader forget that dinosaurs were but a part (a big, incredibly impressive part) of a bigger ecosystem, with each piece influencing the others. No group was isolated from the others, all are interconnected.
Overall, while I had a few minor quibbles, as i mentioned above, I can definitely recommend this book for any elementary library. Some middle school kids will like it too, although those older than that will likely be reading it for nostalgia of the original book, who will find this version a worthy successor.
Other than the image of the 1960 book, all images are illustrations from the book.
Scaly Spotted Feathered Frilled: How Do We Know what Dinosaurs Really Looked Like?
Publication date: 2013. 58 pg.
Houghton Mifflin Harcourt. ISBN: 978-0-547-99134-4.
Author: Catherine Thimmesh is an author of several books aimed at children in elementary to middle school. Her books have primarily focused on people, particularly women, doing science and politics, while bringing a wealth of information along with the human stories. As a result, her books should appeal to many people, helping them draw personal connections to the material. Two of her books, Girls Think of Everything and The Sky’s the Limit, have been listed as Smithsonian Notable Books, the latter book also listed as an Outstanding Science and Social Studies Trade Book for Children in 2002. Her book, Team Moon, discussing all the people besides the astronauts that made the moon landings a success, won the Sibert Award in 2007.
Illustrator: The book is beautifully illustrated by several well-known paleoartists, including John Sibbick, Greg Paul, Mark Hallett, Sylvia and Stephen Czerkas, and Tyler Keillor, as well as Charles Knight, the artist who created the classic pictures shaping the view of dinosaurs for more than a generation. Moreover, there are pictures of skeletons, sketches showing reconstruction from bone to skin, as well as Greg Paul’s classic silhouetted skeletons. As an added bonus, she includes a page at the end with a paragraph about each artist and a fun fact about each one. For instance, Mark Hallett was the person who coined the term “paleoartist.”
I have mentioned this book previously from a review by Brian Switek (for a librarian’s perspective, try the SLJ review here), but I finally got my hands on a copy so I can provide my perspective on it and I have to say, I agree with the other reviews. this is an excellent book well worth including in any elementary or middle school library or classroom. If you know someone who likes dinosaurs and likes to draw, they will like this book. This book gives a great discussion of how artists bring fossils to life, using new discoveries that are changing our views of how dinosaurs looked and comments straight from the artists crafting those visions.
The book wastes no time, providing information on the inside covers. At the beginnig is a timeline showing the different Periods of the Mesozoic Era, with a short description of the overall climate, apleogeography, and notable fauna and flora of the time for each Period. Inside the back cover is a breakdown of the three major dinosaur groups, with a few general facts describing the dinosaursin each group and listing several representative dinosaurs for each group (along with page references for where they appear in the text). Other things that puts the book on my recommended list is a nice index, glossary, and references; things not often found in childrens’ books, which makes this book a cut above. This book does not take the sadly all too common tack of using the “it’s a childrens book” excuse to talk down to the audience and not worry about the facts 9except for one point mentioned by Switek which I will get to later).
The book starts with a discussion of questions the artists ask about the fossils themselves and what scientists can determine from them, such as what can the bones tell us about how they moved and what they ate. Further questions are asked about the plant fossils found in the rocks and what the rocks themselves say about the environment. Was it a desert? A beach? Shallow marine? Once they have what is known, then they can fill in what is not known. The next few pages provide a short history of dinosaur science and the art that sprung from it, such as the early Waterhouse Hawkins Crystal Palace sculptures in London during the 1850s and the Charles Knight paintings adorning the American Museum of Natural History. The book continues with information gleaned from trackways and new technologies helping to spur more discoveries. A discussion of the skeletons leads into reconstructing soft tissues such as muscle and eyes over the bones.
One area in which views have changed significantly is in the skin, which is discussed next. The book describes how new fossils are helping to inform new views, such as feathered raptors, although the book does not mention that we even have evidence of feathers on tyrannosaurs now. This is one area in which the book could have gone farther, it did not discuss much of the diversity of feathers, quills, and assorted spines we have recently found on a variety of dinosaurs. The use of modern animals and analogs and mechanical constraints, such as skin around joints, is also discussed. The problems and possibilities of how one decides on a color is discussed, ending on a mention of new fossils that are beginning to give us amazing insight into actual colors of some dinosaurs.
The information here is not presented as definite conclusions, but as a puzzle, in which the scientists and artists take the various clues and try to piece them together. Sometimes, mistakes are made, such as the thumb spike of Iguanodon was originally thought to be a nose horn. The descriptions demonstrate how vibrant and dynamic the work is. As new fossils and new information comes to light, views change accordingly. The workers must constantly adapt as their knowledge base grows, with each new find getting us closer to a more accurate understanding.
The one quibble I would make with the book is one which Switek also mentioned. The book begins by stating that no one has ever seen a real, live dinosaur, which is not true. We see them every day. They are in fact the most diverse group of vertebrate animals outside of fish. The book mentions that dinosaurs and birds are thought to be related. In fact, it is often said that birds are dinosaurs because birds evolved from earlier dinosaurs. So just like children are still in the same family as their parents, birds are in the same family as all the other dinosaurs. This relationship is a key point in reconstructing fossil dinosaurs. Of course, a lot of people find it bothersome to constantly have to refer to non-avian dinosaurs to refer to only those that lived during the Mesozoic, so it is justifiable to say dinosaurs and birds, so long as it is made clear at the beginning that dinosaurs in that context are only referring to the Mesozoic ones. this book doesn’t do that, which is the only big gripe about the book. Still, a relatively minor complaint compared to the rest of the book, which is done wonderfully.
Teaching how all life is interrelated is a whole lot easier if you can show something akin to a family tree for living organisms. The Paleobiology Database has all the fossils organized by taxonomic relationships to help you find things in the database, but it is not very useful for visualizations. The Encyclopedia of Life has lot of information and multimedia available for over a million individual species and shows how they are classified and is quite useful if one is looking for information on a particular species. But again, it is not very visual.
The Tree of Life website is an excellent website providing a great deal of information on phylogenetic relationships (for good discussion of phylogenetics, try here and here), providing abundant references on the primary literature discussing how scientists think various organisms are related. They work in collaboration with the Encyclopedia of Life, with the EOL focusing on species pages and TOL focusing on relationships. On TOL, one can start at the base of the tree and click on various branches following different groups into smaller and smaller groups, with each page providing what groups are descended from the starting group. For instance, the base of the tree starts with links to eubacteria, eukaryotes, and archaea, with viruses with a question mark. Each one is hyperlinked to a page discussing relationships within that group. It also provides a discussion of possible alternative branchings as well. Thus, the relationships are not presented as “we know this to be true,” but as an active, ongoing process of discovery and research. It is often highly technical, but would be extremely useful for high school students working on an evolutionary or biodiversity topic.
The Tree of Life and the Encyclopedia of Life are great sources for information on species and their phylogenetic relationships, but if you want better visualizations of the sum total of biodiversity, there are other websites that are definitely worth your time.
The first I would like to mention is the Tree of Life interactive by the Wellcome Trust and BBC. Watch the great video with David Attenborough first, then dive into the tree itself. The tree simplifies life to about 100 representative species. It is seriously weighted toward mammals, so provides a very skewed version of biodiversity, but the presentation should appeal to those who are most interested in the overall development from bacteria to humans. If once clicks on any individual species, it highlights the path to the base of the tree and provides a text description and in some cases pictures, a video, and locations. Click on another species and the path to the last common ancestor of the two selected species is highlighted. All the files are open source and available for free download, including the images and videos.
Another interesting site is the Time Tree. This site has a poster that shows 1610 families of organisms available for free download. The poster does a better job of showing the true diversity, but is still heavily weighted towards eukaryotes. However, the real purpose of the site is to provide divergence dates between two species. Simply type in two species names using either scientific (say, Homo sapiens and Gallus gallus) or common name (say, human and chicken) and it will provide how long ago their last common ancestor lived. It should be noted here that the dates listed are estimates based on molecular data. They should not be considered as conclusive dates or anywhere near as precise as listed. Indeed, the value given is a mean value of several estimates, with the median value also given, as well as what they call an “expert result” (which they sadly do not explain). In addition, they provide the scientific references the results came from and the dates provided for each, which can be quite broad. In the example above, those values range from 196.5 to 328.4 million years ago, but of the nine studies listed, all but two fall within 317.9 and 328.4 million years ago. There is also a mobile version of the site, as well as an iPhone/iPad app, as well as a book.
Another site of interest is Evogeneao.com. They have an interesting Great Tree of Life, as they call it, which like most others is heavily weighted toward eukaryotes. They have good explanations of evolution, along with a set of resources for teachers, including an interesting suggestion for how to introduce evolution to students. The interesting part of this site is their discussion of evolutionary genealogy, in which they extend the idea of a family tree farther back than it typically seen. They provide methods to calculate how far removed you are from other species. You can pick from a list of animals and it will tell you how closely you are related. For instance, choosing dolphin returns an estimate of 27 millionth cousin, 9 million times removed. That nicely encapsulates not only the idea of relatedness, but the immense scales of time we are talking about.
The Interactive Tree of Life, or iTOL, is another interesting site that may be of interest to high school teachers. This site utilizes genomic data as the basis of its trees and, unlike the others, provides a better visual indicating how truly diverse prokaryotes are in relation to us. It also allows you to print out phylogenetic trees in different formats, depending on your preferences and what sort of information you want to display. You can even upload your own data if you wish, but most teachers will likely choose to stick with the displays already provided, as there are simpler programs to deal with trees that any but the most precocious senior high school student (or college student for that matter) may wish to create.
There are a few other interactive trees out there that may be more appropriate to younger viewers. One is at the London Natural History Museum website. This one is very simplistic, having only sixteen branches, with four of them being primates, but it gets the point across. This interactive is limited to providing the link between any two branches and the name of the group containing both. For instance, clicking on the banana and the butterfly gives the name Eukaryota. Another site provides an interactive for the poster Charles Darwin’s Tree of Life. This interactive allows one to zoom in on any part of the tree and if one clicks on an animal, a short description of the animal is provided. Sadly, the two best interactives I have yet seen are not available on the internet. I had the opportunity to explore DeepTree at the Harvard Natural History Museum and it is truly spectacular, as is their FloTree. If you get a chance to see them, you should. Hopefully, one day they will be available in a broader format than now.
All of this assumes of course, that people actually know how to read these trees, which is a false assumption in that most people really do not. So it would be useful to spend some time getting familiar with proper interpretation of them before using them in class. There are several resources explaining this (such as here and a really excellent video here), so I will not put a tutorial on here unless there are requests to do so.
All images posted here are from the websites being discussed and are copyrighted to them.
It may seem that the earth is pretty stable. You can always count on the mountains being there when you look for them. But the Earth is a dynamic place. Volcanoes, floods, landslides, and earthquakes all change the landscape in ways we can see quickly. What we don’t typically see is that if we expand these processes over long periods of time, those same processes alter the landscape far beyond our experiences. The surface of the Earth is covered in a crust broken up into numerous plates, which are constantly shifting and moving. The plates only move between 2.5 – 15 cm/year (the previous link contains information on how this is measured and provides activities for teachers for use in the classroom), but add this up over millions of years and the Earth looks quite different. Add into this mountain-building and erosion wearing down the mountains and you get radically different geographies for the planet.
So what did the Earth look like in the past? There are two excellent sources providing maps of the planet through time. The first is the PALEOMAP Project, by Dr. Christopher Scotese. On this website, you will find maps ranging from 650 million years ago to the modern day and even into the future. There are 3D animated globes and interactive maps. He includes a methods section for how the maps wer put together and a list of references and publications. There is also a climate history section providing brief descriptions of the climate at various points in time. For teachers, there are several educational resources available, some of which are free, but others are available for a fee. There is even an app for the iPhone/iPad. It is not available yet for either android or Windows, but that has been admirably taken care of by the Howard Hughes Medical Institute with their Earthviewer app and they have done a wonderful job. the app is fully interactive, allowing easy scrolling through time and full rotation of the globe. You can also track atmospheric oxygen and carbon dioxide, day length, important fossils, biological and geological events, and major meteor impacts. The app even provides a bibliography of their source material. In addition to the maps from Dr. Scotese, the app extends the timeline back to 4.5 billion years (although this extension is obviously not nearly as detailed as the Scotese maps due to the greatly extended time and the greatly decreased amount of available data). All in all, a great app, also reviewed by the NSTA.
The second site that will be of interest is the Library of Paleogeography run by Dr. Ron Blakely. These maps cover approximately the same time frame as those provided by Dr. Scotese and are not animated. However, Dr. Blakely provides maps in different projections and provides regional coverage beyond that of global maps. So if you are specifically interested in paleogeographic maps of North America and Europe, this is an excellent resource.
A third site also provides paleogeographic maps which are very useful. In this case, the maps are secondary to the main purpose of mapping fossil locations. The Paleobiology Database contains records of fossil locations that have been published in the primary literature. One can perform a search by organism or group, country, rock unit or type, time interval, paleoenvironment, or publication. The results from the search are mapped onto global maps based on the PALEMAP Project.
All of these sources are available to the public and are used by professional researchers. Therefore, one can safely assume they represent accurate assessments of current, generally accepted thoughts on our Earth through time. You may notice that maps from Scotese and Blakely may not completely agree on all aspects. This is because it is very hard to piece together all the evidence and trace the movements of the continents backwards through time. Often, the data is incomplete and they have to make judgment calls based on the available evidence. Not everyone makes the same choices. This is true even for maps of current geography and is even more so for paleogeography. As we get more data and better techniques, those disagreements become fewer and fewer, but there is still much work to be done, so these maps can and will most likely be refined in the future to reflect new research.
By Dr. Nic Bishop
Publication date 2000. 48 pg. Houghton Mifflin Company. ISBN: 0-395-96056-8.
Nic Bishop has combined his avid love of photography and his doctorate in biology into a prize-winning series of books for children. His books include a series on specific groups of animals, such as snakes, lizards, marsupials, spiders, butterflies, as well as a “scientist in the field” series. It is the latter series I am discussing today. There are plenty of books available discussing the different animals, although few with the quality of photography and biological expertise Bishop brings to his work, but there are precious few that discuss the work of the scientist in bringing that knowledge to light as the discoveries are being made, which is what particularly interests me here.
Digging for Bird-Dinosaurs was published in 2000, so it is not current, but is still topical and relevant and should stay so for some time. The only issues with the age of the book are new details that have been discovered, which further confirm the hypotheses presented in the book. When the book was written, most scientists had been convinced that birds evolve from dinosaurs for many reasons which are mentioned in the book. Since the book has been published, many new feathered dinosaurs have been found which clearly show the relationships in further detail. But the book is not really about the relationships between birds and non-avian dinosaurs, although it discusses them quite well, it is about the experience of the people on an expedition to Madagascar in 1998, what it is like being in the field and the study of some of the fossils that were discovered. If you want to know what it is like to go to another country and dig for dinosaurs, this book will be of interest and should make interesting reading for kids in elementary or middle school.
The expedition was led by Dr. David Krause, a professor at Stony Brook University in New York who has been running paleontological expeditions to Madagascar since the early 1990s and is still doing so, although the book is focused on his colleague, Dr. Cathy Forster, also of Stony Brook (at the time, but now an Associate Professor at George Washington University). She, like Krause, is a noted paleontologist and is likely the focus of the book because of the relative paucity of women in the field sciences. These days, if one goes to a meeting of the Society of Vertebrate Paleontology, women are well represented, but in the 1990s, most of these women were still students looking to the few women like Dr. Forster who were forging careers.
The book follows their experiences in the field and the discovery of a particularly interesting bird-like creature they eventually name Rahonavis. The book continues with the team bringing the fossils back, preparing them out of the rock and studying them, coming to the conclusion that the animal was the closest known bird to Archaeopteryx, which is generally considered the earliest known bird. It is so close in fact, that many scientists today consider it actually closer in lineage to the dinosaurs known as dromeosaurs, which include animals like Velociraptor, than it is to birds. This placement is a great demonstration that birds really did evolve from dinosaurs. It is so hard to tell the difference between “dinosaur” and “bird” in the earliest bird-like forms because they are not distinct, separate groups. Birds are merely a subset, a type of dinosaur, in much the same way that mice are rodents, which are also mammals, which are also amniotes, which are also vertebrates, etc. Therefore, whether or not Rohanavis falls out before or after Archaeopteryx in the lineage is a mere detail, changing nothing of the story. It makes as much difference to the evolution of birds as it does which of a set of twins was born first or second, a matter of inconsequential minutes in evolutionary time.
One of the fascinating parts of the book is when Dr. Krause and Dr. Forster discuss the local people helping them. The villagers are very poor, with no access to healthcare or schools. Dr. Krause was concerned enough that he founded the nonprofit Madagascar Ankizy Fund, which supplies needed healthcare to the area, as well as building schools and providing teachers. Dr. Krause and Dr. Forster came to Madagascar to hunt for fossils. But while they have found a great many spectacular finds, perhaps their greatest accomplishment is in the humanitarian work on behalf of the people who live there.
Dinosaur Odyssey: Fossil Threads in the Web of Life
By Scott D. Sampson
Publication date 2009 (hardback) 2011 (paperback). 332 pg. University of California Press. ISBN: 978-0-520-24163-3.
Suitable for junior high students and up.
Author: Dr. Sampson is best known these days as Dr. Scott the Paleontologist, from Dinosaur Train on PBS KIDS (a children’s show I can recommend). But he doesn’t just play one on TV, he is a real-life paleontologist, and a well-respected one at that, best known for his work on late Cretaceous dinosaurs in Madagascar and the Grand Staircase-Escalante national Monument. He is Chief Curator at the Denver Museum of Nature and Science. He has a blog called Whirlpool of Life and can be found on Facebook. Dr. Sampson has had a longstanding interest in public science education, particularly about connecting children with nature. That interest is clearly evident in Dinosaur Odyssey.
This book has been out a few years, but its main message is more deeply relevant now than ever before. This book is not really about dinosaurs. It is about the interconnectedness of all things. Dinosaurs are simply a fascinating hook for discussing ideas about evolution and ecology. If you are looking for a book that just talks about dinosaurs, look elsewhere. But if you want a book that puts dinosaurs in context as part of a complete and ever-changing ecosystem, if you want to learn about the Mesozoic world as a stage upon which dinosaurs are only a part, however awe-inspiring and prominent, of a much larger web of life, this book is for you. In Dr. Sampson’s hands, dinosaurs are not skeletons of bizarre creatures, they are living organisms interacting with others, changing and being changed by their environment. In a similar vein, our ideas about them are neither set in stone nor idle speculation, they are dynamic and changing, based on new discoveries and scientific understanding, circling ever closer towards a deeper understanding.
The book is written for someone with decent reading ability, but not a dinosaur aficionado. No real prior scientific knowledge is required, simply a desire to learn about the natural world. For those who want more, or find some of the terminology daunting, there is a wealth of notes and references at the end, along with a substantial glossary. The book begins with a short history of the scientific study of life and Sampson’s personal experiences searching for dinosaurs in Madagascar, which led to some of his thinking for the book as an introduction to what follows. Throughout the book, he uses his personal experiences to enrich the scientific discussions, making it a personal story, not just an academic one. Chapter two is an ambitious glimpse at the history of the universe until the dinosaurs appear, along with a short discussion of the geological principles forming the foundations of our understanding of geologic time. Chapter three introduces the dinosaurs, defining what is meant when a scientist talks about dinosaurs and the different groups of dinosaurs. Along the way, he discusses what species are, how they are named, and how we figure out relationships, although not in detail, just enough for a non-science person to understand the broad concepts. Chapter four discusses the physical world of the Mesozoic in terms of plate tectonics and how the movement of the continents shaped the world and thus the evolutionary history of dinosaurs. He even discusses the role of the atmosphere and oceans in climate. Chapter five builds the basics of ecosystems and nutrient flow, chapter six provides a background in evolutionary theory, chapter seven discusses how dinosaurian herbivores adapted to changing plant communities and how the dinosaur and plant communities may have co-evolved, each influencing the other. Chapter eight adds predators to the mix and chapter nine finishes the ecological chain with decomposers. Chapters ten and eleven discuss sexual selection and metabolism in dinosaurs.
The chapters to this point built up how dinosaurs fit into the ecosystem and the workings of evolutionary theory. The next three chapters then take that information and discuss the dinosaurs rise to prominence in the Triassic, development of dinosaur ecosystems in the Jurassic, and their ultimate development through the Cretaceous period. Chapter fifteen, as might be expected, discusses the extinction ending the Mesozoic Era and the dominance of dinosaurs as major players on the world stage.
One might think the book would end at this point. But Sampson has one final chapter to go, which is probably the most important message in the book. He finishes the book by discussing why dinosaurs are important today. We are facing an extinction event equal to the end of the Cretaceous in terms of biodiversity loss, yet few people seem to notice just how comparatively depauperate our global ecosystems are becoming. Because dinosaurs draw peoples’ attention, they are the perfect tool to discuss evolutionary and ecological issues. In this chapter, Sampson discusses how to use dinosaurs to reach people and teach them about our own ecosystems, how we are affecting it and the problems we are facing. In this way, looking at our past through a dinosaurian lens can help us find our way forward.
In the final analysis, this book is a must-read for anyone interested in the natural world and how it works, especially if they love dinosaurs.
Publication date 2007. 427 pg. Random House. ISBN: 978-0-375-82419-7.
Author: Dr. Holtz, self-proclaimed “King of the Dino Geeks,” or as I like to call him Dr. Tyrannosaur, is a well-known and respected paleontologist who’s understanding of all things tyrannosaur is unparalled. As a senior lecturer at the University of Maryland and the Faculty Director of the Science & Global Change Program for the College Park Scholars, he has extensive teaching experience. I have had the pleasure of attending several of his talks at meetings of the Society for Vertebrate Paleontology and he has always been informative and interesting and his students have always been very positive about him.
Illustrator: Luis Rey is an accomplished and respected artist, known especially for his paleo art. He has won the Society of Vertebrate Paleontology Lazendorf Award, given to outstanding artists and his artwork can be seen in several museums, books, and other outlets. He is known for very colorful dinosaurs with close attention to anatomical detail. He makes huge efforts to bring dinosaurs to life as actual, living creatures with as much accuracy as possible. A few have criticized his artwork for being too fanciful, in that he draws wattles and other structures on dinosaurs for which we have no hard evidence. But these structures are extremely difficult to preserve in fossils and their living relatives do have them. Matt Wedel, a noted dinosaur researcher in his own right (although he studies sauropods, not theropods like Dr. Holtz) has said, “If you go bold, you won’t be right; whatever you dream up is not going to be the same as whatever outlandish structure the animal actually had. On the other hand, if you don’t go bold, you’ll still be wrong, and now you’ll be boring, too.” Luis Rey has never been called boring.
I decided to start off my reviews with this book, even though it has been out since 2007, because I think every school should have it. There are good reasons it won “Outstanding Science Trade Books for Students K to 12: 2008 by the National Science Teachers Association. It is called an encyclopedia and it does have chapters describing all the various dinosaur groups, but it is so much more. It is not a small book and here is my only real criticism of the book. Despite its title, it is not quite a book for all ages (School Library Journal rated it Grade 5 and up and it would take an exceptional 5th grader to read it). If you are looking for a book to read to little kids, look somewhere else. It is called an encyclopedia for a reason. Nevertheless, with that caveat in mind, if you are looking for a book to give your dinosaur-obsessed kid who can read well, this book is for you. It is not just for kids though. Adult dinosaur enthusiasts will like it too.
What I like best about this book is that it does not simply focus on the dinosaurs. There are plenty of books that will give you an A-Z description of dinosaurs. Holtz gives the reader a feel for what paleontology is and how it works. The goal of this book is to explain why we think what we do about them, how we know what we know. He starts off the book discussing how science, particularly as it applies to paleontology. He then has a chapter on the field’s history, followed by three chapters of geology and geologic time to put everything into perspective. Chapters 5-9 discuss how paleontologists find fossils and attempt to reconstruct what they looked like and how they are related to each other. It is not until chapter 10 that he even starts talking about dinosaurs themselves and that chapter simply explains how they are related to other vertebrates. Chapters 11-35 are the meat of the book that everyone would expect. This is where he discusses the amazing diversity of dinosaurs. The last five chapters discuss dinosaur behavior and metabolism and how we approach topics like this that are not so easy to see in the fossils. The last three chapters then put the dinosaurs in context of time and ecology. Contrary to popular opinion, dinosaurs did not all live at the same time. They spanned a vast length of time and these chapters give the reader some sense of what the earth was like during the major time periods, who lived when and what other animals they lived with. The last chapter ends predictably with a discussion of extinction, but rather than just say the asteroid killed them all off, Holtz discusses some of the complications of that hypothesis, finishing off with how life continued after the asteroid impact (including the dinosaurs, who were only mostly dead, not completely dead, a few made it through and thrived as birds). At the end of the book is a series of tables listing all the dinosaurs, including where and when they lived and their estimated size and weight.
Holtz doesn’t go it alone either. Scattered throughout the chapters are inserts from other researchers (such as Dr. Kristi Curry Rogers shown here) explaining various topics related to their own research, so the reader gets the perspective of many paleontologists, not just the author’s.
A serious bonus for this book is that Dr. Holtz has attempted to keep the book as current as possible by posting online corrections necessitated by new research, which you can find here.
As a final word, the book is superbly illustrated with numerous drawings, both in monotone and vivid color, by Luis Rey. There are no images of actual fossils, which some have criticized the book for, but my personal feeling is that the book was not designed to be a textbook for dinosaurs. It was designed to show the dinosaurs as living animals, not simply as their bones. There are plenty of other places one can find that. This book is for a view of what they were like alive and most importantly, why we think they were like that shown here and how we study them.