Category Archives: Dinosaurs

Science in dinosaur movies: Jurassic Park, then and now

The 1993 movie Jurassic Park, based on the book by Michael Crichton and directed by Steven Spielberg, is seen by most enthusiasts as the best dinosaur movie that Hollywood has produced. It set a high-water mark in the genre for many reasons: it took dinosaurs seriously as a topic, and did not portray the animals simply as ridiculous extras; and the movie was amazing for its visual effects. For any movie from Jurassic Park onward, your dinosaurs had better look real, scary, and believable.

Jurassic Park was also important in that it showed dinosaurs more or less accurately, consulting with real paleontologists in its making, and working to utilize the latest and greatest views on dinosaurs. This is not to say that they did not put in a Hollywood spin, or as I have called it in the past, “Spielbergize” some of the dinosaurs, but as a paleontologist I could really see that the ideas were not completely out of the blue. In fact, Spielberg foreshadowed some of the findings about dinosaurs that were to come.

I want to review some of the key features of Jurassic Park as they were thought of in Hollywood in 1993 and compare that with the state of the art today.

Dinosaur DNA

The entire premise of Jurassic Park is that DNA from extinct species was collected and cloned in order to bring the animals back to life. Are we any closer to being able to do this? Well, not really.

The complete DNA code of any single species is very long and complex, and it is very unlikely that any DNA molecule will survive intact for millions of years. We cannot even clone species that are modern or recently extinct with much success, and we have access to their DNA. The technical difficulties of getting DNA intact, knowing how to put that DNA together on chromosomes, knowing how to trigger the genes on the chromosomes to turn on and off during development, means that even if we could somehow get a complete dinosaur DNA sequence, we could not make a living animal.

However, there have been some amazing advances in molecular paleontology, where protein fragments and amino acids have been shown to be able to survive within fossil bone for an extraordinarily long time, much to the surprise of scientists who assumed that fossilization would destroy the tissues at the molecular level. Making predictions is difficult, especially about the future. Who knows what discoveries await us, but for now, the current best answer is that we will never be able to clone a dinosaur. (See Mammoth protein designed to be cool for more on molecular paleontology).

Excavation Scene

Early in the movie we are treated to a scene of a paleontology excavation as modern paleontologists dig into the past to understand dinosaurs. As with any profession, portrayal in a movie is not often close to reality. Cop movies do not realistically show what it is like to be a cop. Lawyer and doctor movies stretch the true on those professions, and the excavation scene was the one where me and my professional colleagues got a good laugh.

We see the field crew effortlessly dusting sand away from crisp fossil bone. We see the team firing off seismic charges to send waves into the rock to visualize complete dinosaur skeletons underground, just waiting to be effortlessly dug out. Oh boy. This is so far from the truth.

We cannot simply use a type of remote sensing technology to visualize unexposed fossils, however there are a few technologies that people have tried to use. Sometimes the minerals that fill fossil bone have a higher concentration of radioactive elements, and so mapping the concentration of radioactivity over a site has helped to locate concentrations of fossils in those cases.  There is a technology called ground-penetrating radar which under certain circumstances could be applied to fossils, but its use is limited. The main problem with both of these techniques is that to find fossils underground, you have to be able to tell them apart from the surrounding rock, and too often the fossils are very similar to the rock that encases them.

Fossils are still found the old fashioned way—by looking for bones weathering out on the surface, and digging around them in hopes that something more is there.

And of course, it is not as simple as dusting them off. Fossils are often enclosed in a hard matrix of rock, which can take many hours of tedious labor to remove. Frequently in the field the fossils are exposed enough to understand how they are laid out, and then removed in giant blocks to be worked on back in the museum lab for the next several years.

Velociraptor

The undeniable stars of the movie were the “raptors.” As shown, they were cunning and relentless killers, bent upon creating havoc for their human character counterparts. In the movie, the velociraptors were shown to be about as tall as an adult human and perhaps 12 feet long nose to tail. That was an exaggeration to say the least.

Real velociraptors have been excavated in Central Asia, and are not known from North America as fossils. However, there are Velociraptor relatives known from this continent. But in life, real velociraptors were only about half the size shown in the movie, maybe the size of a mid-sized dog.

However, Spielberg did not know it, but his velociraptors did not have to be exaggerated in size if he had just said that they were a dinosaur species that was discovered in 1991, and named in 1993—Utahraptor (Kirkland et al. 1993). The same year that Jurassic Park was released also saw the emergence of Utahraptor, a dinosaur that much better fits the dinosaur shown on film. It was discovered in North America, as was suggested for Velociraptor in the movie, and was the size of the animals shown in the film. So, in a way, Spielberg was showing a real dinosaur, just not the one he thought.

Tyrannosaurs Running

It might be a close call as to which was more popular in the movie, Velociraptor or the seminal favorite dinosaur Tyrannosaurus. Who did not thrill to see the giant animal trash Jeeps, eat lawyers, and run amuck? In a harrowing scene, tourists of Jurassic Park are chased at top speed by the Tyrannosaurus and only just manage to escape in their vehicle.

Could Tyrannosaurus almost outrun a Jeep? Well, likely not.

Large animals today do not run well. The heavier an animal is, the more force there is on the animal’s joints and bones, and running compounds the effects of those forces. Modern elephants cannot run, but rather trot. They can move quickly, but they are too large to achieve a full-scale run.

How to kill Tyrannosaurus

How to kill Tyrannosaurus, from Farlow, Smith, and Robinson, Journal of Vertebrate Paleontology, vol 15(4).

Likewise, tyrannosaurs were very large and heavy animals, and there are physical constraints based upon the strength of their bones and joints. And unlike an elephant, Tyrannosaurus supported all their weight upon two legs, teeter-tottered over their hips. Running would have placed tremendous stresses on the hip joint.

Also, unlike an elephant, the large head of a tyrannosaur was extended out over the ground, as much as 15 feet above the surface, and they did not have forelimbs of any size to speak of. This means that if they did get up to a significant running speed and were to stumble, their heads would fall with great force to the ground without any way to break the fall. In short, if they did run and fall they would bash their brains out on the ground. Running, in this case, would be fatal.

Venomous dinosaurs

In Jurassic Park, the dinosaur Dilophosaurus was portrayed as being able to spit blinding venom into its victim’s eyes. The suggestion that a dinosaur was venomous was groundbreaking. Earlier this year there was a report of the discovery of a venom delivery system in a raptor dinosaur, Sinornithosaurus (Gong et al. 2010), seeming to once again make Spielberg a paleontological prognosticator.

However, it does not seem likely that the interpretation of Sinornithosaurus as being venomous will stand up to further scrutiny. Secondary investigations of the fossils suggest that characters which were viewed as supporting a venom delivery system are actually not what they were first thought (Gianechini and Agnolin 2010), so it looks like we still have to wait to find a venomous dinosaur, much less one that can spit!

Jurassic Park stands as one of the greatest dinosaur movies. From a paleontology stand point, while the movie is fiction several interesting propositions were shown, and this is, after all, what drives our curiosity to explore.

Dinosaur movies at Amazon

References:

Gianechini, F. A., and F. L. Agnolin. 2010. A reassessment of the purported venom delivery system of the bird-like raptor Sinornithosaurus. Paläontologische Zeitschrift.

Gong, E., L. D. Martin, D. A. Burnham, and A. R. Falk. 2010. The birdlike raptor Sinornithosaurus was venomous. Proceedings of the National Academy of Sciences 107(2):766-768.

Kirkland, J. I., R. Gaston, and D. Burge. 1993. A large dromaeosaur (Theropoda) from the Lower Cretaceous of eastern Utah. Hunteria 2(10):1-16.

Related Posts:
Learn about dinosaur toys
Dinosaur excavation in the Purgatoire River Canyon

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Accurate Dinosaur Toys

If your kids are fascinated by dinosaurs, and many are, you might like a recommendation on some of the best dinosaur toys out there. Being a paleontologist and museum professional for many years I do have some experience with quality dinosaur models.

Without a doubt some of the best and most accurate models you can get for dinosaurs and other prehistoric animals are from the Carnegie Collection. A number of features of these models, produced by Safari, make them highly recommended.

First, most of the models were sculpted to the same scale, 1:40. This means that almost all the models can be directly related to each other, so you can easily compare the size of a Brachiosaurus with an Apatosaurus, for example. Not every model is the same scale however, so you do have to watch that as it could be misleading.

Sauropod dinosaur models from the Carnegie Collection

Sauropod dinosaur models from the Carnegie Collection. Left to right are Camarasaurus, Diplodocus, Brachiosaurus, and Apatosaurus.

Another significant thing about the Carnegie dinosaur toys is that they are all hand painted, meaning that there are no two models that are identical. Each one is a bit different and special.

Finally, the models have been in production since 1989, and they add new species to the series almost every year. Some species from the series are retired from the line, meaning they are no longer available commercially, which might give them some collector appeal. And occasionally species already represented in the series are re-sculpted based upon new scientific evidence about their appearance or mode of life.

Various dinosaur models from the Carnegie Collection

Various dinosaur models from the Carnegie Collection. Back row, left to right, Spinosaurus, Kronosaurus, Plesiosaurus, Deinosuchus, Tyrannosaurus. Front row, left to right, Allosaurus and Pteranodon.

The Carnegie models are some of the most accurate dinosaur toys on the market today, and we use them regularly in our museum education programs. If you are looking for some great models, these are hard to beat.

Pick yours up at the Boneblogger store. Look in the recommended section.

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Spending time in Purgatoire

One of the many places that I have been fortunate to spend time in is Purgatoire. Perhaps not the same thing you are thinking, but I am referring to the Purgatoire River Canyon in southeastern Colorado. Located south of La Junta, this area is an often-overlooked gem. The scenic vistas could be used for your desktop wallpaper!

Purgatoire River Canyon in southeastern Colorado

Purgatoire River Canyon in southeastern Colorado

The many names applied to the region can be confusing. The Purgatoire River has cut a dramatic canyon in this part of the plains, and with the Rocky Mountain Front Range far to the west, it can be almost startling to come upon the deep canyon in an otherwise rolling plains landscape. Anglo settlers bastardized the name of the river, and instead of the eloquent Purgatoire, ended up calling the area Picket Wire, so both names alternately apply.

The area is managed predominately by two federal agencies, the United States Department of Agriculture’s Forest Service and the Department of Defense through the Army. The military uses their lands for maneuver practice, as I understand it, tanks and other mechanized equipment. Some years ago the Army carved off some of their land and gave it to the Forest Service to manage as part of the Comanche National Grassland. The Forest Service land is used for recreation and also the preservation of significant historic and prehistoric resources.

Petroglyph of human and horse figures

Petroglyph of human and horse figures

Rourke Ranch house in the Purgatoire Canyon

Rourke Ranch house in the Purgatoire Canyon

The historic resources include Native American petroglyphs and other archeological sites, early Spanish homestead sites and churches, early American homesteads. The prehistoric resources include dinosaurs and other prehistoric animals, both body fossils and trace fossils. I was very fortunate to have been involved in the documentation of some of the first dinosaur fossils from the region (Schumacher and Liggett 2004).

Dinosaur trace fossils, in particular dinosaur tracks, are well preserved in one section of the Morrison Formation in the bottom of the canyon. These tracks were discovered in 1935 by a young girl as can be seen in this newspaper clipping from the Topeka Capital Journal. However, the tracks are most definitely not those of a Tyrannosaurus rex (mentioned in the clipping) as that beast did not stalk the Earth for at least 90 million years after the track-makers walked here. This track site is the largest continuous track site of dinosaurs known from North America, and contains over 1,400 prints.

Newspaper clipping announcing the discovery of the Purgatoire track site

Newspaper clipping announcing the discovery of the Purgatoire track site

However, because of the remoteness of the site, scientists turned their attention to other dinosaur tracks found in Texas, and the Colorado tracks were essentially forgotten for many decades. However, a newer generation of scientists have re-examined the track site. Of interest is the fact that the site shows five parallel sauropod tracks, suggesting that at least in this case, the animals walked along together spread out, not walking in a line (Lockley 1991).

There are actually several track layers in the rocks. Also preserved are several three-toed theropod, or meat-eating dinosaur. While it is difficult to exactly match the track to the species of dinosaur that made them, the large sauropod tracks were made by an animal like Apatosaurus (Brontosaurus of old) and the meat-eating tracks are similar to what an Allosaurus would make.

A well-preserved theropod dinosaur track in the Purgatoire Canyon

A well-preserved theropod dinosaur track in the Purgatoire Canyon

View of the Purgatoire River track site using low altitude photography

View of the Purgatoire River track site using low altitude photography

In addition to the tracks, the canyon is also now yielding body fossils of dinosaurs. It is really no surprise since the Morrison Formation is extensively exposed along the river canyons. The Morrison is the name given to a wide-spread formation that is the most prolific producer of Jurassic dinosaurs in North America. The formation outcrops in North Dakota, South Dakota, Montana, Wyoming, Colorado, Oklahoma, Texas, New Mexico, Arizona, Utah, and Idaho. Every Jurassic dinosaur you have ever heard of comes from the Morrison; animals such as Allosaurus, Apatosaurus, Diplodocus, Stegosaurus, and Camarasaurus all come from this formation. (See Formations for information about what that means.)

Stratigraphic section of the Purgatoire River Canyon showing the geologic formations that outcrop

Stratigraphic section of the Purgatoire River Canyon showing the geologic formations that outcrop

Given the Purgatoire River’s remoteness, and the fact that it was controlled for many years by the Army, few people were able to explore the region until more recent decades. Thus, now it is one of the last areas of the Morrison Formation exposures to be explored. And it is proving to be as rich as expected.

Over the last decade, the Forest Service has been conducting Passport in Time (PIT) programs in the canyons, looking for new dinosaur sites, and excavating sites. Many people, scientists, graduate students, and the lay public have enjoyed excavating dinosaurs in this beautiful and remote canyon. And several significant specimens have come out of the area. The Forest Service has partnered with many museums from the region to study this treasure-trove and to allow people to enjoy this amazing region.

Volunteers excavate dinosaur fossils from the Woody site

Volunteers excavate dinosaur fossils from the Woody site

Dinosaur vertebra from the Woody Site being prepared at the Sternberg Museum of Natural History

Dinosaur vertebra from the Woody Site being prepared at the Sternberg Museum of Natural History

Plastered dinosaur bone being carried out of the LC Site

Plastered dinosaur bone being carried out of the LC Site

Volunteers excavate dinosaur bones from the Morrison Formation at the LC site

Volunteers excavate dinosaur bones from the Morrison Formation at the LC site

The Forest Service offers tours of the canyon and track site. If you are interested contact the Forest Service Office at 1420 East 3rd, La Junta, CO 81050, 719-384-2181. If you plan to visit the area on your own, be aware of a couple of things. You cannot drive into the canyon without prior authorization. You can hike in on your own, but it is several miles in and out, and the summer temperatures can be brutal, so bring plenty of water and plan accordingly.

A large section of Dakota Formation slumping away from the main block provides a dramatic hiking experience

A large section of Dakota Formation slumping away from the main block provides a dramatic hiking experience

Lockley, M. G. 1991. Tracking Dinosaurs: A New Look at an Ancient World. Cambridge University Press, New York.

Schumacher, B. A., and G. A. Liggett. 2004. The dinosaurs of Picketwire Canyonlands, a glimpse into the Morrison Basin of southeastern Colorado. Journal of Vertebrate Paleontology 24(Supplement to 3):110A. (Poster page 1 and page 2).

Many other dinosaur facts can be found here at Boneblogger. Just search or select the category.

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Dinosaurs dragging their bellies—Huh?

Isaac Newton famously wrote in 1676,“If I have seen further it is by standing on the shoulders of Giants.” This gets to the heart of the scientific process—a gradual addition and refinement of human knowledge and understanding of the natural world. But, of course, sometimes even giants had wacky ideas.

The particular “giant” to whom I refer is Charles H. Sternberg, famed fossil collector. Sternberg began collecting fossils when he was seventeen, at a time when it was not exactly commonplace, in about 1867. And he dedicated his life to this unusual pastime, founding a family of fossil collectors when his sons continued the tradition for a second generation. Together, the Sternberg family collected a huge number of fossils for museums and science. There is hardly a major museum in the world that does not have one of their discoveries on display.

Sternberg started his career in the hills of western Kansas, collecting fossil plants from the Dakota Formation. He sent his specimens back to the young Smithsonian Institution, for which he received a letter of acknowledgment that he treasured his whole life. He was bitten by the “fossil bug.”

Edward and Charles Sternberg

A rare photograph of Charles Sternberg (right) with his twin brother Edward (left).

By 1875, he enrolled in college where he studied briefly under Benjamin Mudge. Mudge organized a fossil collecting trip for 1876 to collect for O. C. Marsh, the Yale College paleontologist. Sternberg was too late to sign up with Mudge, and bitterly disappointed, and somewhat brazenly, he wrote a letter to Edward D. Cope, Marsh’s rival.

Sternberg wrote, “I put my soul into the letter I wrote him, for this was my last chance. I told him of my love for science, and of my earnest longing to enter the chalk of western Kansas and make a collection of its wonderful fossils, no matter what it might cost me in discomfort and danger. I said, however, that I was too poor to go at my own expense, and asked him to send me three hundred dollars to buy a team of ponies, a wagon, and a camp outfit, and to hire a cook and driver. I sent no recommendations from well-known men as to my honesty or executive ability, mentioning only my work in the Dakota Group.” (Sternberg 1909, pg 33).

Sternberg anxiously awaited a reply, and when he opened Cope’s letter, a draft for $300 fell out, a very significant sum. So began his professional fossil hunting career. Over the years he collected throughout the American and Canadian west. In the twilight of his career he semi-retired to San Diego, and was allowed to use the title of curator at the natural history museum.

Museums and libraries are marvelous places, full of fascinating treasures. It was while reading in the archive at Fort Hays State University’s Forsyth Library that I came across a carefully saved clipping of an article from the  Los Angles Time Sunday Magazine from December 20, 1931, titled “The habits of dinosaurs,” written from an interview with the 80 year old fossil collector.

In the article, Sternberg is quoted as giving his vision of the life of some of the dinosaurs that he had collected over the many years. While I recognize that it is not really fair to judge the views of earlier experts, especially with the perspective of almost three quarters of a century of additional knowledge, but it can be damn funny.

Sternberg is quoted as authoritatively saying, “Dinosaurs were lizards. They stood and walked like lizards, not like elephants or rhinos. That is to say, the normal positions of their feet were outside the line of the body, just like the alligators of today, not inside or even with the line of the body, as are the feet of horses, elephants and other mammals. Moreover, the dinosaur, instead of standing up, on straight legs, as usually pictured, bent its legs outward, as do the lizards, and dragged it belly on the ground, again like the alligators, monitors and other large lizards of the present day.”

Dinosaur reconstructions of that period typically showed dinosaurs with spindly, lizard-like limbs, and tails dragging, but with a generally upright posture. Sternberg evidently did not agree, arguing in favor of his views with some odd reasoning.

Citing fossils of preserved dinosaur skin, he said, “Furthermore, the skin on the lower side of the abdomen of this dinosaur was much thinner and more delicate than on other parts of the body. This is further and strong argument for my claim that the dinosaur dragged its belly on the ground, as do the alligators of today, which so protect their vital parts from carnivorous animals…you may be sure that no tender-stomached dinosaur, whether it weighed forty tons or forty pounds, would voluntarily expose its tenderest and most vital parts to attacks by the tyrant dinosaur or any other carnivorous creature by walking erect.”

Illustration from Los Angles Times Sunday Magazine, 1931

Illustration from Los Angles Times Sunday Magazine showing Sternberg's idea of dinosaur stance.

I totally agree. I hate walking around with my “tenderest” parts exposed. The accompanying illustration of Sternberg’s vision of the Mesozoic is hilarious, with giant sauropod (long-necked) dinosaurs hunkered down, presumably guarding soft spots. I am not really sure how Sternberg expected it would work for a forty ton animal to push itself along the ground with its legs sprawled out to the side, much less how it would support its own weight on its chest, but details, details.

Even though the article claims that Sternberg was a “man of facts and not fancies,” he was prone to exuberant musing about the prehistoric beasts he collected. While he could be wacky, we owe a great debt to the entire family for their contributions to science.

Further reading about the Sternberg family:

Everhart, M. Oceans of Kansas website, summary of the work of Charles H. Sternberg.

Everhart, M. J. 2005. Oceans of Kansas: A Natural History of the Western Interior Sea. Indiana University Press, Bloomington.

Liggett, G. A. 2001. Dinosaurus to Dung Beetles: Expeditions Through Time, Guide to the Sternberg Museum of Natural History. Sternberg Museum of Natural History, Hays, Kansas.

Rogers, K. 1991. The Sternberg Fossil Hunters: A Dinosaur Dynasty. Mountain Press Publishing Company, Missoula, Montana.

Sternberg, C. H. 1909. The Life of a Fossil Hunter.

Other interesting dinosaur facts are found here at Boneblogger. Search or select the category for more.

Sternberg, C. H. 1917. Hunting Dinosaurs in the Bad Lands of the Red Deer River Alberta, Canada. Charles H. Sternberg, San Diego.

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Feathered dinosaurs may have changed coats

Some of the most exciting finds of the last couple of decades were the discovery of feathered dinosaurs. These fossils mostly have come from fine-grained formations of the Cretaceous Period in China, where feather impressions were preserved along with the bones. Each of these fossils gives us a snapshot image of the body covering sported by that species. Other recent finds have even given us clues to the coloration of the feathers in a few species.

In yet another new find, announced in the April 29 issue of Nature, we learn that the feathery covering may have fundimentally changed over the lifetime of individuals of at least one species. Two small oviraptors in the genus Similicaudipteryx were preserved at different stages of their life history, each showing the pattern of feathers covering the body at different life stages.

Artist reconstruction of a juvenile and adult Similicaudipteryx

Artist reconstruction of a juvenile and adult Similicaudipteryx. Artwork by Xing Lida and Song Qijin

The smaller, juvenile individual had short flight feathers with a “ribbon-like” stem on its forearms, much long feathers on the tail, and a downy covering over the rest of its body. The larger, young adult individual showed a different pattern, with much longer, and more developed flight feathers with a strong central shaft on the forearm. Thus, the flight feathers of the forearm show two very different morphologies at the two life stages. This does not happen in modern birds, where the flight feathers that emerge on the juveniles are the same, only smaller versions of the adult feathers.

There is some debate that this interpretation of the fossils is correct. It could be, argue some paleontologists, that the smaller individual was preserved during a molting phase, with the new feathers only partially emerged from the tube-like sheath that feathers form in. In other words, they suggest that the different morphology is only temporary and an artifact of preservation. The authors of the original paper maintain it is not an artifact based upon the proportions of the feathers. So, we need to keep digging.

It is now accepted that the ancestors of birds were the theropod (meat-eating) dinosaurs. It is clear from these fossils, and many similar ones, that birds inherited their feathers from dinosaurs, and we have greatly expanded our knowledge of feather evolution with the last few years.

Other dinosaur related posts can be found here. Just search or select the category.

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