Heron Tracks

I just spent a very busy four days walking up and down the beaches of Florida's Panhandle. I was counting heron tracks for a wildlife index. I had three sites, each about an hour and a half walk along white-sand shoreline. I learned a lot about heron habits and tendencies but also made some sketches of the tracks out there in the state and national parks. Besides heron tracks, I also encountered some other big bird tracks. The one on the right isn't from a heron. It's an osprey track. The real giveaway was the slightly sideways projecting toe. It was nearly as large as the track of the heron, though.

Sketches at Tarkiln Bayou

Detail from my sketch pad. This is supposed to portray the setting sun.

Sketching in nature is a lot different from photography. The results aren't as stunning; they usually aren't something you'd want to show off. They tend to be messy, hard to see, and not particularly artistic. A photograph is exact, beautiful, and colourful: an art form.

However, sketching is a much slower process. A photographer can rush through the underbrush, snapping away at whatever catches his or her fancy. A sketcher, by comparison, must sit in one place and carefully attempt to reproduce some small aspect or picture of the environment onto paper. This slower pace forces the sketcher to notice things that the photographer often misses. The shapes of the leaves and stems of plants become more interesting than the flowers. The silence of immobility sharpens underused senses. The salty smell of the bayou. The wailing of a family of loons. A sudden splash from a jumping mullet. These things become the focus--and how to portray them in art. A quiet yet lively mood, all on paper.

Sketch of the eastern shoreline of Tarkiln Bayou

While listening, watching, and smelling these things, I scribbled the shapes I could see around me onto the paper. Tarkiln Bayou was calm, a glassy series of rolling ripples sliding along the salty surface between the stems of the needle-rush. The loudest sound was the mullet, jumping periodically to clean their gills. But one splash caught my attention. A different tune in the rhythms of fish, bird, and plant. I focussed my attention on the north shore, where a series of ripples was racing out from the cover of a breeze swept strip in the bayou. The silver patch of water, reflecting the sky, appeared to be supporting the base of a growing V of white wave, it's tip picking up speed toward the shore. It ended in a spasm of splashes. This fast swimmer soon moved back out into the bayou, edging closer to me with methodical surfacing, puffing out a breath of air, a blow, at each rise. It was soon clear what had approached.

Sketches of a stump in the water.

The dolphin was one of several, the others working different parts of the shoreline. It would chase the mullet toward the reads and catch it near the shallows. Amazingly, the dolphin didn't eat it's catch immediately but, rather, playfully threw the wounded fish up into the air. Sometimes the fish would try to escape, and the dolphin would chase it again, seeming to enjoy the game it had created. I was feeling extremely blessed to observe such unique behaviour. The dolphin nearly swam right under the boardwalk, flippers sticking up in the air, glossy belly and under-tail gleaming whet as it threw its head back to fling the fish over it's chin. Once the fish was no longer able to perform any "live entertainment," the dolphin presumably swallowed its catch and repeated a race into the shoreline for another mullet. Of course I feel a little bad for the mullet, but I was completely overwhelmed with joy. Fun and games is a characteristic of intelligence and character. Both qualities are possessed by dolphins and it was a real privilege to observe it first hand.

Sketches of water and plants at Tarkiln Bayou.

As the blows of the dolphins grew faint, and the light was fading from the horizon, I sang to my fluttering heart and danced back to my vehicle. A truly magical moment, to meet someone so different that could consider my existence, just as I consider his. I wonder if he even saw me.

Yangchuanosaurus zigongensis portrait

In accordance with the renovations I am doing for all my blogs, I have changed the purpose of this one as a showcase for my art. This is a portrait I completed over the holidays of Yangchuanosaurus zigongensis, a three-and-a-half tonne theropod that has been uncovered in China. Like an Allosaurus of the orient, it would have been the top predator of its ecosystem. I used the colours of a beautiful agamid lizard as a model for what I've produced here. It probably wasn't as brilliant as this in life, but it looked good to me.

Art: Dilophosaurus wetherilli

Tussling theropods has been a classic depiction of paleoart ever since Charles R. Knight painted a beautiful canvas of two Dryptosaurus. Since then, Dilophosaurus has often been featured and I know I am not the first to illustrate something of this nature. Of course, the coloration is purely speculative but I thought that, with crests like they have, they must have made a fantastic display.

Art: Archaeopteryx lithographica

I actually made three previous drawings of this bird but they were all unsatisfying in some respect. The first looked to dinosaurian, the second was posturing strangely. This one seemed to be the best. Although not particularly well preserved in Archaeopteryx, I felt the long leg feathers were appropriate since most other flying deinonychosaurs had them. In spite of its very birdlike appearance, I prefer to consider Archaeopteryx a dinosaur because its basic anatomy is nearly identical to that of the dromaeosaurids and other Deinonychosauria that are nearly always considered dinosaurs. Archaeopteryx might even belong to the same created kind as Velociraptor, implying that it too had feathers.

Art: Guanlong wucaii

Because similar dinosaurs like the feathered Dilong paradoxus are considered distantly related to Guanlong, it has been speculated and widely accepted that Guanlong had feathers. However, from a creationist's perspective, these two species are not related. Dilong is more tyrannosaur-like, even sporting two fingers, in contrast with the three long fingers of Guanlong. Thus, there is no reason for creationists to believe Guanlong had feathers, though there is also no reason for creationist to believe they didn't have them either. In this illustration, I couldn't decide if I would give it feathers or not. In the end, the neck was unscaled and sported some quill-like structures on top, indicating that their may be feathers elsewhere on the body, but I leave that up to the audience's discretion.

Art: Rebbachisaurus garasbae

There really aren't any good skeletal restorations of this dinosaur available. I did find some photographs of the skull online, which proved helpful. Additional aspects of the body were based on Nigersaurus taqueti, a related species. Perhaps I should try my own skeletal restoration for this species some day.

Art: Marasuchus lilloensis

Most of the time, when I illustrate a protodinosaur like this, I'm thinking Lagosuchus talampayensis. Unfortunately, that creature is fairly fragmentary and the much better preserved Marasuchus lilloensis serves as a model. These were swift, bipedal archosaurs that raced across the soft, tropical grounds of their Triassic-type habitat (I refer to "Triassic" as a subset of pre-flood ecosystems, not as a geological age). This illustration took me about 10 minutes, hence some sloppy edges.

Herrerasaurus ischigualastensis - Reig, 1963

Remains: Two complete skulls and several partial skeletons (Paul, 2010) including juveniles and adults (Paul, 1988).

Size: 4.5 meters (15 feet) long and 200 kilograms (450 pounds).

Location: Ischigualasto Formation of San Juan, Argentina (Weishampel et al., 2004).

Biology: Herrerasaurus ischigualastensis is the key species for all the Herrerasauridae. It is far more complete than other species and can be considered the “typical” herrerasaur. Like others of the family, H. ischigualastensis had four toes on its hind feet (though only three of these bore weight), giving better traction and stability but less speed and maneuverability compared to other theropods, but of these things it had no need, because all its prey animals and the predators that might have hunted it were slower still.

It preyed on the smaller cynodonts and rhynchosaurs of its environment. To dispatch these victims it probably used its large backward facing teeth. It would make a lunge, perhaps with its five-fingered hand or perhaps with its deep jaws. Once the teeth had been pushed into the flesh, there would be no escape even for the most determined prey. It would have made short work of any soft-bodied animal such as a cynodont by utilizing a hinge on the lower jaw that allowed for a slicing action of the serrated teeth.

The hands and jaws probably worked in coordination with each other to maneuver prey. The arms were long and three of the fingers were long and clawed (the other two were short and provided more of a grasping palm).

H. ischigualastensis was the most common predator in its environment and had little to fear most of the time. However, it was not the top predator. Saurosuchus was a huge rauisuchian that could have easily taken the life of a herrerasaur given the chance. Luckily, rauisuchians are top heavy and move about on all fours so, as long as Herrerasaurus kept its wits about it, it could out maneuver and out pace the larger carnivore.

Herrerasaurus led a relatively quite life for a theropod. The bones show no sign of stress so the animals would have done little active movements that involved bashing, bruising, or other activities that might stress the bones (Rothschild et al., 2001). This is supported by the scleral rings (eye bones) which bear similarities to animals that are only active for short periods throughout the day (Schmitz et Motani, 2011). However, some Herrerasaurus bones do have puncture wounds that match the teeth of other Herrerasaurus, so inter-species fights of a violent nature must have been fairly common. The wounds had been infected, but healed successfully (Molnar, 2001). A herrerasaur predator may have left some of these wounds, particularly those on the skull (Sereno et Novas, 1993). Saurosuchusis a likely culprit.

The habitat in which H. Ischigualasto lived experienced both a wet and dry season but it would have been at least fairly moist all year round. Ferns, horsetails, and giant conifers would have been common, as in any Triassic-type habitat and would have been thick across the forest floor. Signs of volcanic activity and heavy rainfall indicate that these animals died during the global flood in a situation probably involving volcanic activity.

Selected Organisms:

Aetosauroides schagliai

An aetosaur of fairly plain features, having short legs that hold its body close to the ground and no spines on the margins of its dorsal plates. It was about 3 meters (10 feet) long. It was a likely candidate for a Herrerasaurus ischigualastensis menu though, being so heavily armored, it would not have been the easiest option.

Exaeretodon frenguellii

An herbivorous cynodont about 1.8 meters (5.9 feet) long, having large incisor-like teeth at the front of its jaws. It was one of the largest traversodonts and a likely food source for Herrerasaurus ischigualastensis.

Hyperodapedon sanjuanensis

A strange, squat reptile with a beak and broad, flat head, it was only 1.3 meters (4.3 feet) long. It was chunky and heavily built. Though it might have used its narrow, sharp beak protruding form its upper jaw as a defensive mechanism, it was also a very likely food source for Herrerasaurus ischigualastensis, along with Exaeretodon frenguellii.

            Ischigualastia jenseni

A large dicynodont which grew close to 4 meters (13.2 feet) in length and weighed more about 2.5 tonnes. It was the largest animal in the Ischigualasto Formation. It sported a frill-like structure around the back of its head to protect the neck and had a horny beak with downward protruding edges, almost like tusks. Its overall bulk of body is reminiscent of a hippopotamus. It would have been a difficult task for a Herrerasaurus ischigualastensis to bring down, but so much meat was likely worth the effort.

Saurosuchus galilei

At 9 meters (30 feet) long, this was the top predator of the Ischigualasto and likely provided a consistent source of trouble for Herrerasaurus ischigualastensis. It was a rauisuchian, with a large skull and deep jaws filled with large, serrated and curving teeth. While it was certainly capable of hunting and likely targeted the large dicynodonts (above) it would not have been above steeling kills from a begrudging Herrerasaurus.

Eoraptor lunensis

A small dinosaur similar in proportion to Herrerasaurus ischigualastensis, but judging from its teeth, it was more of a generalist taking invertebrates and even plants. It would likely have fallen prey to Herrerasaurus, given an encounter.

Notes: Synonymous with Ischisaurus cattoi and Frenguellisaurus ischigualastensis.

References:

Nesbitt, Sterling J., Randall B. Irmis, et William G. Parker. March, 2007. “A Critical Re-evaluation of the Late Triassic Dinosaur Taxa of North America”. Journal of Systematic Paleontology. Volume 5, Issue 2. http://www.tandfonline.com/doi/abs/10.1017/S1477201907002040#.UcjA66XNvao

Molnar, R. E. 2001. “Theropod Paleopathology: A Literature Study”. From Mesozoic Vertebrate Life. Darren H. Tanke and Kenneth Carpenter (editors). Indiana University Press, Indiana. Pages 337-363.

Olsen, Paul E. and Donald Baird. 1986. “The Ichnogenus Atreipus and its Significance for Triassic Biostratigraphy”. From The Beginning of the Age of Dinosaurs: Faunal Change Across the Triassic-Jurassic Boundary. K. Padian (editor). Cambridge University Press, New York. Pg 61-87. http://www.ldeo.columbia.edu/~polsen/nbcp/olsen_baird_86.pdf

Paul, Gregory S. 1988. Predatory Dinosaurs of the World: A Complete Illustrated Guide. Simon and Schuster, New York.

Paul, Gregory S. 2010. The Princeton Field Guide to Dinosaurs. Princeton University Press, Princeton.

Rothschild, Bruce, Darren H. Tank, and Tracy L. Ford. 2001. “Theropod Stress Fractures and Tendon Avulsions as a Clue to Activity”. From Mesozoic Vertebrate Life. Darren H. Tanke and Kenneth Carpenter (editors). Indiana University Press, Indiana. Pages 331-336.

Safran, J. et E. C. Rainforth. 2004. “Distinguishing the Tridactyl Dinosaurian Ichnogenus Atreipus and Grallator: Where are the Latest Triassic Ornithischia in the Newark Supergroup?”. Abstracts with Programs. Geological Society of America. 36(2): 96. https://gsa.confex.com/gsa/2004NE/finalprogram/abstract_70257.htm

Schmitz, Lars and Ryosuke Motani. 2011. “Nocturnality in Dinosaurs Inferred from Scleral Ring and Orbit Morphology”. Science. Volume 332, Number 6030, pages 705-708. http://www.sciencemag.org/content/332/6030/705

Sereno, Paul C. and Fernando E. Novas. 1993. “The Skull and Neck of the Basal Theropod Herrerasaurus ischigualastensis”. Journal of Vertebrate Paleontology. Volume 13, Number 4, pages 451-476. http://www.tandfonline.com/doi/abs/10.1080/02724634.1994.10011525#.UdZzQqVuDao

Weishampel, David B., Peter Dodson, et Halszka Osmolska (editors). 2004. The Dinosauria. University of California Press, Berkeley.

The Sad Case of the Wolfville Mystery

The Wolfville Formation seems to be connected to the famous Chinle Formation, the vegetation, though undocumented in this formation, would be similar. While little is known about the ecology of this bygone habitat specifically, it would be similar to other Triassic-type habitats, like the Chinle. More importantly, the presence of many tracks and seeming absence of plants may tell a story about how the formation was formed. How these creatures met their doom. My guess, in line with a Biblical model of earth history, is as follows:

The Wolfville was a rich, Triassic-type habitat. The air would be humid and warm, typical of rainforest environments and, on this particular day, it rained like never before. bennettite conifers thrashed and flailed in the downpour. In the underbrush, bellow the otherworldly cycads and ferns, a menagerie of reptiles dwelt. There were dinosaurs. Small, beaked herbivores trotted through the brush and paused under the whiplike leaves of a Czekanowskia tree. The call of a coelophysoid dinosaur echoed through the fluvial valley, and the heterodontosaurids trotted on. Like everything in this environment, they were strange plant-eaters. As they moved, their front paws touched the ground leaving funny four-footed prints in the mud between the horsetails. They also had large fang-like teeth curving from their lower jaws. Usefull for splitting plant stems, yes, but also an efective line of defense if one happened to be cornered by the massive, long-legged rausuchian, which looked something like a tall crocodile with the deep jaws of a T. rex. Bat-like pterosaurs buzzed between the trees as dusk set, catching insects. From beneath the ferns, a small reptile called a procolophonid emerged. It looked like an overgrown horny-toad with spines sticking out from the back of its skull. It snuffed the air warily and then ducked back away as a pair of cynodonts, looking like crosses between dogs and lizards, trotted by on their search for tubers on the shore of the lake.

The bizarre Teraterpeton squats on the remaining piece of high ground and overlooks a wasteland of dinosaur corpses. This little hill will offer little protection, however, as the second tsunami-sized wave strips the landscape of life once more.

In the lake, there would be phytosaurs; crocodile-like archosaurs with their nostrils nearly between their eyes, like a whale. Deeper in the water, nestled in the muddy bottom, lay perhaps the only familiar shape to us. A freshwater mussel. And it can feel the rumbling an approaching storm.

Perhaps the strangest creature here is the Teraterpeton. Like many of the creatures in the Wolfville, its body was built like a lizard. However, its head was long like a crocodiles and it had only a few teeth near the back of its jaw. The end of its snout ended in a stork-like beak. A plant-eating crocodile lizard. All this strange biodiversity was soon to be ended.

The rumbling grew closer and louder, and then a crack of falling tree echoed in the distance. All ears turned and the heterodontosaurids wondered what mischief the rausuchian was recking over there. But now even the rausuchian had reason to fear. Another tree, closer than the first, split and it was quickly followed by another. Suddenly, the river swelled and pushed the lake up over its shores. Cynodonts dashed for higher ground, but that mattered little. A wave, crashing through the forest, tore up trees and stripped ferns from their roots. In a matter of minutes, the area was ravaged and stripped by a tsunami-sized wave from the global flood. Most of the plants were washed out and the remaining animals found themselves scrambling for higher ground. Perhaps some of them made it, leaving tracks in the mud, whilst others found themselves cowering under the shadow of the second wave, larger and more powerful than the first. This they could not resist and their bodies were crushed and broken and ground, tracks were freeze framed in an instant filling of overlying mud, and the ecosystem was lost forever. This seemingly plantless landscape of reptiles was preserved as the Wolfville Formation. Amazingly, there were still survivors after this mayhem. Or at least one. Only one set of tracks is found in the overlaying Blomidon Formation, indicating that one last theropod, a lonely coelophysoid, wandered over the mud flats. It glanced at the half-burried corps of the thorny procolophonid but it didn't stop. There was no time for scavenging. On the horizon an object foreign to the dinosaur loomed up off the normally flat horizon. It's a massive volcano, larger than Yellowstone's peak. The exhausted dinosaur squinted its eyes at the glowing mass of magma. Suddenly, the lake of fire burst into glowing shards of stone and a massive flow careened across the flats, with nothing now to stop its decent, and coated the landscape in a layer of basalt miles wide. No living thing would survive this disaster. Everything with the breath of life would die.

These three layers, the Wolfville Formation, the Blomidon Formation, and the overlying basalt layer, testify to these events. It opens one's eyes to the horror that was the global flood. It was no sudden or instant burial. It came on more slowly than you  might think and each animal (and man, for that matter) struggled for his own hold at survival. But it was to no avail. Fear God; He is a righteous judge. Water times two coated the Wolfville, then fire. The next judgement will be only fire and certainly not any more instant than the global flood.

Polar Dinosaurs?

There has been a suspicious increase in paleo-illustrations of dinosaurs tromping through an icy field with snow on the ground. It seems logical that such creatures, in subarctic landscapes, would have a coating of feathers, thus supporting the idea of feathered dinosaurs (some dinosaurs did have feathers, by the way), which could be taken as evidence for evolution. Indeed, if there was such an "age of dinosaurs" than we would expect to find dinosaurs in existence in every environment. Why should they be devoid of the poles?

What the Heiberg, a typical "Triassic" habitat, might have looked like before its impending doom of 4000 years buried in rock layers. I have restored Arctosaurus (the small coelophysoid silhouette emerging from the forest) in its traditional form, as a dinosaur. However, it is based on a single vertebrae and it is impossible to say if it is a dinosaur at all. It may well be any other archosaurian reptile and it has even been suggested that it was a turtle of some sort. 

1. Clathropteris meniscoides (fern); 2. Sphenobaiera spectabilis (ginkgo);
3. Arctosaurus osborni (dinosaur); 4. Neohimavites peregrinus
(ammonite); 5. Oxytoma kiparisovae (clam); 6. Podozamites sp.
(bennettite); 7. Meleagrinella antiqua (clam); 8. Ginkgo siberica (ginkgo);
9. Taeniopteris tenuinervis (conifer); 10. Neocalamites hoerensis
(horsetail).

Well, there are dinosaurs at the poles. With this in mind, the evolutionist might expect to find evidence of these polar habitats in the farthest reaches of north and south. There are fossil beds there. The Heiberg formation of the Northwest Territories houses one of them. The Heiberg, an ecosystem that is now deposited in northern Canada, may demonstrate that the earth was indeed tropical from pole to pole or, more likely, it demonstrates that, during the global flood, the remains of an ecosystem were carried far from it’s original location. The habitat seems to be of a fairly typical Triassic type, but sampling is insufficient, at least in regards to animals. Plant evidence is fairly complete and illustrates that the habitat was probably a tropical swamp of some sort, possibly a kind of coastal mangrove. To evidence this, bennettites (a cycad-like tree with unique reproductive structures) have been found with bivalve mollusks between their roots in some places. The other trees in the forest are cycads, gingkoes, and araucarias (monkey puzzle trees). It would have been a strange jungle with a groundcover of a variety of ferns species and a couple species of horsetails on the muddy shoreline. The mud of the swamp teamed with a couple species of bivalve mollusks while, amid the water between the trunks of bennettites, ammonites suspended themselves to wait for a passing meal.
The Heiberg is a great example of a tropical environment uncovered near the north pole. Some pond slowly buried over millions of years? I think not. It is another piece of evidence against the uniformitarian way of thinking. Things have not always been the way they are now.

Pangaea: Mystery of the Broken Continent

Attempting to Map the Ecology of the Super Continent

Anyone looking at a map of the world will likely notice that it looks a bit like a jigsaw puzzle. Especially in the Pacific, the edges of the Americas and Africa look like they must have fit together at one time. Indeed every scientist that I've heard speak or write on the matter has been under the impression that all continents were attached at one time. This hypothetical giant landmass is known as Pangaea.

Pangaea is a mystery among evolutionists and creationists alike. Scientifically, the only evidence we have to run on is in the fossil record, the point in time marking the very end of the pre Flood world. So, in essence, the only way to know what the world looked like before the flood is by studying how it was destroyed. Not a lot to go by. Fortunately, the Bible also adds to our knowledge, providing the framework of a global Flood, continental drift, and oceanic water levels. However, there is still a host of unanswered questions.

First off, water levels must be taken into consideration. The Bible speaks of the "springs of the great deep" and the "floodgates of the heavens" breaking forth in Genesis 7:11 (NIV). Before the flood, much of the planet's water was pent up in these two locations ("the great deep" and "the heavens"). When they finally released their holds of liquid, it would have contributed to water levels to a certain level, depending on how much water actually was released. The Bible informs us that it was enough to cover "all the high mountains" of that pre Flood globe, so it was a lot of water. Viewing a map of the seafloor, I can see that the continental shelves, especially between Alaska and Siberia, and in southeast Asia end far out to sea. I think it is safe to postulate that these continental edges would have been uncovered before the floodwaters came. Strangely, I haven't heard anything about this in creationist circles but it would be a significant factor. 

Another interesting point is the question of continental drift. Whether Pangaea divided during or sometime after the Flood is a debatable question (there is not reason to believe it happened before the Flood). Evidence for a post Flood division include Biblical references to the earth dividing in the days of Peleg from Genesis 10:25 and 1 Chronicles 1:19 (NIV). A later date would also give time for animals to disperse to the various continents during the Ice Age (because of all the glaciation, water levels would have been lower then, too, creating land bridges). However, even the Ice Age shouldn't be taken for granted. If it happened during the Flood, one is left postulating about giant tortoises floating across the sea on "vegetation mats" and interpreting the Biblical word "earth" as "nations."

Also important is the question of ecological provinces on Pangaea. For example, the Morrison is a large geological formation in Wyoming, Utah, and other states. Is this formation representing an ecological region on the same land that is North America today? Bone beds, sandstone layers, and other evidences of watery currents indicate that the organisms were carried by water and deposited there so they didn't die and get berried slowly as evolutionists postulate. So, how far were they carried from their original dwelling place? At present, I think that the distribution of fossil species indicates that they did die near enough to where they had lived. Theoretically placing the continents together, then sampling from the fossil beds on each continent provides an accurate map of various species ranges. Similar species shared between each continent provides the links that theoretically hold the continents together. These links are very clearly defined, I hope to write more on this later.

A trio of metoposaurs (large extinct amphibians) feed in the shallows of a pond. There is little doubt that such ecological niches existed, but was there any rhyme or reason to these ecosystems and can we detect and map them?

Besides the above major factors, Pangaea ecology hangs in the balance by many other considerations. Volcanic activity may have played a role in a fossil location, similar to how continental drift does. A shifting plate of the Earth's crust might shove a fossil bed away from a volcanic region and keep Flood deposits toward valleys. A careful study of the geologic column and its accuracy might also provide clews as to which habitats were buried first, beginning with deep marine reefs to cooler mountain habitats dominated by mammals. It's all so highly hypothetical at this point but, in an upcoming post, I will attempt to provide a creationists map of Pangaea. The results are turning out to be quite surprising and may provide answers to questions that have been plaguing palaeontology for years.

Stegosaurus stenops

This Dinosaur Has God's Name All Over It!

No other dinosaur displays our Savior's handiwork quite like Stegosaurus.

Remains: Two complete skeletons and many partial and fragmentary skeletons. Both Adults and juveniles (Weishampel et al. 2007).

Size: 6.5 meters (21 feet) long and 3.5 tonnes in weight (Paul 2010).

Location: Lived in the lower Morrison Formation of the Preflood world. Skeletons are now found fossilized in Colorado, Wyoming, and Utah (Weishampel et al. 2007).

Habitat: The Morrison was a semiarid habitat of mixed prairie and damp woodland riddled with rivers.

Ecology: Stegosaurus would have browsed on shrubs and small trees. When full grown, the only predators large enough to face it would have been large theropods like Ceratosaurus nasicornis and Allosaurus fragilis.

Taxonomy: Belongs to the Stegosauridae monobaramin with Tuojiangosaurus, Gigantspinosaurus, and Kentrosaurus. There is at least one other species of Stegosaurus, S. ungulatus. It defers from S. stenops in that it was slightly larger (7 meters and almost 4 tonnes) with narrower, more pointed back plates.

Stegosaurus was the epitome of large theropod disembowelment. Unlike most other dinosaurs, Stegosaurus had no stiffening fibers running the length of its tail. Such fibers would normally function in stiffening the tail to aid in balance but the heavy bodied stegosaur wouldn't have needed them. In addition to this unrestrained feature, the stegosaur had extra space between its caudal (tail) vertebrae allowing for ultimate flexibility (Bakker 1986). This feature alone would have made Stegosaurus the ultimate in self-defense, but the Creator thought better. To increase its range of motion, the stegosaur had special features on its forearms too. Each humerus had an immense deltoid crest for the attachment of the deltoid muscles. This growth on the bone almost seems disproportionate but looking at the muscle attachment regions on the scapula (shoulder bone) indicates a very large deltoid muscle, indeed (Bakker 1986). With extra power, the stegosaur could pivot on its front legs to swing its entire hindquarters into the blow, allowing the dinosaur to deliver a hit to a predator attacking near its head. Such a powerful blow would drive the four spines at the tails end so deep into a theropod's guts it would have killed it certainly.
Despite all these incredible features of self defense, the stegosaur's head was still vulnerable. To compensate, this dinosaur had a tight network of bony rounds under its chin to protect the throat. The back plates too ran up to the back of the head. Considering that the predators of the Morrison were nearly 2 tonnes in weight, the stegosaur's armory wasn't overkill.

Stegosaurus was well equipped with a horny beak
and battery of leaf-shredding teeth.

Of course, Stegosaurus didn't spend much time battling theropods (not many dared risk a confrontation). Its massive gut needed filling. Stegosaurus lived in a habitat crawling with giant sauropods. While their long necks were reaching into the tops of the evergreens, the underbrush was being cropped by smaller hypsilophodonts and dryosaurs. Stegosaurus, on the other hand, was perfectly designed for reaching the vegetation that grew in between. It had a perfect beak and battery of teeth for processing its food, this equipment was carried fairly low to the ground. To gain extra height, the stegosaur could rear an extra few feet into the trees. To do this, Stegosaurus had a system of muscles and ligaments running the length of its tall vertebral spines. It worked just like the cable of a crane, levering the stegosaur's beak up into the leaves (Bakker 1986).

Dorsal view of a Stegosaurus stenops skull.

Stegosaurus plate design and function is still debated. Based on some of the best specimens, it is a general consensus among paleontologists that the plates were arranged in two rows in an alternating fashion (Lessem et Glut 1993). The purpose of the plates, however, is far from settled. Some have postulated that they served as solar panels that exposed a network of blood vessels to the hot sun. Or perhaps those blood vessels served a function in communication, turning the plates bright red as the blood flooded the microgrooves in the bone. Not that Stegosaurus needed more weaponry, but even if the plates did serve one or both of the former functions they most likely worked at defense as well. The plates were not attached to bone and it's probably safe to presume that they didn't just flop around limply (an evolutionist partial to vestigial organs might think so). Rather, they almost certainly had attachments for skin muscles (Bakker 1986). These muscles, lying on the surface of the skeletal muscles, would have provided control of the direction of the plates. As an allosaur charged in at the stegosaur's side, it could orient its plates to face the foot-long jaws.
All said and done, Stegosaurus stenops was the ultimate in mega self-defense. It had incredible armory and perfect design for herbivorous feeding. In the predator/prey balance put in place after God's perfect curse on creation, stegosaurs were the perfect piece. When one thinks of design in creation, Stegosaurus doesn't often come to mind. I hope it does now.

This sketch illustrates Stegosaurus stenops lifting to pluck a choice bit of greenery from a limb.

References:

Bakker, Robert. 1986. The Dinosaur Heresies. William Morrow & Company, Inc. New York.

Lessem, Don and Donald F. Glut. 1993. The Dinosaur Society Dinosaur Encyclopedia. Random House, Inc. New York.

Paul, Gregory. 2010. The Princeton Field Guide to Dinosaurs. Princeton University Press. Princeton, New Jersey.

Weishampel, David B., Peter Dodson, Halska Osmolska. 2007. The Dinosauria. University of California Press. Berkeley.