Prehistoric Warfare Episode 4: Apatosaurus vs Saurophaganax

Now for something different. In 2004, Animal Planet showed as new series called Animal Face Off, a series reconstructing conflicts between coexisting animals. While the execution was clumsy and lacking, the concept is strong and I think easily applied to prehistoric fauna.  Ideally, there would be professionals discussing the situations, but unfortunately, you have only me. First I will compare the animals, and then depict their behavior, before concluding with the final battle.  The outcome will be my personal opinion; and there would be many times when the outcome would be decidedly different. This is not a scientific consensus, but one researcher’s opinion.

We all love dinosaur battles. They’re always a high point in a film. It’s childish, but it’s just plain fun. So, I’m hoping to use this opportunity to use this almost-universal appeal to get people thinking and talking about ecology, biomechanics, and behavior. Only one or two of these stories will be based on actual fossils-the rest are likely possibilities that must have happened sometime or another. In real life, animals usually don’t fight on even terms, but it does happen. Sometimes prey turn the tables, sometimes predators quarrel between themselves, but it can happen. I hope you enjoy this. Again, first I will have two scenes, one for each animal showing them in their habitat and showcasing their particular skills, then finally concluding with a battle between the two.


I MUST WARN THAT  THIS WILL BE VIOLENT. IF YOU HAVE A PARTICULARLY VIVID IMAGINATION, OR HAVE AN AVERSION TO GRAPHIC NATURALISTIC VIOLENCE, I STRONGLY SUGGEST NOT CLICKING ON THE CUT

The last time on this feature, we saw the Morrison formation, a lush, diverse fauna of dinosaurs of the American West. We return to Utah and Colorado this episode, only 5 million years later. 5 million years is but a small drop in geologic time, but as long as there is pressure for a species to survive, evolution will occur.  Things have gotten wetter-the giant salt lake T’oo’dichi spreads for hundreds of miles across, and salt marshes dominate the continent. This is the beginning of the great inland sea that will soon cut through the very center of the continent.

The rivers have widened in these past 5 million years, and the lakes have returned. The great wetlands support giant trees, and said giant trees have supported giant life forms.  Some of the old giant dinosaurs remain, but others are replaced by even larger species. Allosaurus and Stegosaurus continue their ancient duel, but they are dwarfed by the new fauna.

Here are some now-the Diplodocus longus herd we saw last time has been replaced by a new one devastating the conifers. These are Diplodocus hallorum, and they are huge. The old species could rise on their hindlimbs to send their necks even higher, but these are so big and heavy they are too heavy for such a maneuver. The high hoots are longer and deeper, and their hides charcoal rather than slate grey.  And they’re huge; even the juveniles are a match for Ceratosaurus,  and the largest over a hundred feet long.  One specimen will be called Seismosaurus, the earthquake lizard, and indeed the shallow freshwater ponds tremble at their passes.

It’s the height of the wet season, when the rains come down the highest. It’s raining right now, hard and thick, and it has been going on for days. The rain is a blessing, diluting the salt water enough for the plants and animals to flourish in greater numbers. For a brief time in the year, lake T’oo’dichi will be coated with a vast mat of algae.

Meanwhile the Diplodocus inevitably knock down the giant trees with casual movements of the neck and shoulders. Whatever greenery survives is added to the rich vegetable soup. The local Stegosaurus herd ducks their tiny heads into the floating plant detrius, their tiny ornithopod neighbors living up to their Drinker names by drinking the water as it falls and swimming in the rising water.

Swimming after them are Coelurus-these small, feathered theropods have outlived their sister genera through their speed and agility, capable to keeping up with the agile prey.  Dryosaurus, now resting on the logjams of the swamp streams, are still too big for Coelurus and too fast for Allosaurus.

On the other end of the spectrum, a new species of Apatosaurus joins the wet salad bar. Louise’s Brontosaur is even bigger than the Ajax and Marsh species and the size of the now-rare Barosaurus. They will be protagonists in this weeks’ confrontation. Among them is a late-surviving Brachiosaurus, even larger and even rarer than the ones we saw previously. Its size has now been matched by the new Diplodocus and giant brontosaur Supersaurus.

This wetness has promoted more diverse theropods. Allosaurus, now represented by a new species, is still king, but Ceratosaurus are more of a rival, as is the local predator here.  He makes his debut on this scene by startling some small newcomers, Uteodon. Uteodon are regular prey for Ceratosaurus, but 35-foot long Torvosaurus is interested in larger game. Torvosaurus like the wetlands, and make their living ambushing large prey, stealing kills from the smaller Ceratosaurus, and being able to decimate local crocodile populations when stressed. He’s bigger than Allosaurus but much rarer and slower. He usually doesn’t chase after the agile ornithopods-he eats old stegosaurs and many sauropods.

The rain thwarts his smell and vision, but he is patient. He knows there’s abundant prey, and that his preference, sauropods, get stuck in the mud. They’re heavy and their weight are supported by narrow feet-he’s lighter and his broad feet allow him to outpace and outmaneuver them.  This is his time of year-drier lands that favor his Allosaur rivals become soaked with water. He spends most of his time by the shores of Lake T’oo’dichi, but he’s gone upland in the flood.  It’s a good thing, too-Torvosaurus will soon be extinct in another few centuries with the coming wave of volcanism.  Their white-tipped heads and huge red bodies will soon be an ancestral memory.

Right now, however, it’s his time. He’s killed many young sauropods this month, and in this forest the herds cluster and muddle with each other.  As the rain slackens and thins, the Brachiosaurus has displaced the young Apatosaurs and some are starting to wander off to avoid the traffic jam. Perfect prey.

The problem is his position. A logjam, still topped with Dryosaurus, prevents one flanking attempt-the logs will be difficult to overcome and the Dryosaurus might alarm the sauropods with their shrill cries. Coming in from the other side will mean sneaking past a big adult Stegosaurus and towards a clump of adult brontosaurs. His brain is primitive, but Torvosaurus only takes a few minutes to make his decision. He’ll attempt the Stegosaurus-if it’s stuck in the mud it’ll be easy prey and if it can move it will shuffle on by.

Torvosaurus draws near; Stegosaurus moves off, its deadly tail casually slicing through the foggy air rather than into the Torvosaurus. Now he’s in position and slowly makes a beeline toward the juveniles. It’s then that the rain stops.

One of the brontosaurs sees the gleam of the white eye-crests. Allosaurus’ is red, so Torvosaurus co-evolved as to make them distinguishable. Torvosaurus’ smaller cousin Marshosaurus has the same color scheme as the former species, but it’s evolved to be a mimic to intimidate rivals and deceive onlookers as to their identity at a distance. Of course, once an allosaur comes close enough to find out, the Marshosaurus’ scheme is up and is usually sent sprinting away.

There’s nothing deceptive about Torvosaurus, nor is running away part of the behavioral repitoire. Big and robust, they can outmuscle most anything, even Allosaurus. Of course, there’s exceptions and Apatosaurus adults are one of them.  The Apatosaurus that saw those familiar, terrifying crests sounds the alarm. Now the entire herd is alert. The rain created aural, visual, and scent static that muffled Torvosaurus’ approach. The grey mists part just enough for the maroon predator to appear. The smell of water and plants is cut into by a smell known by all dinosaurs here to be the herald of terror. The drone of the rain covered the low-frequency breathing and sloshing through the shallows.

Apatosaurus has excellent hearing, albeit only for low-frequency sounds and for sounds carried through the ground and water.  While their infrasound detection is muffled by the water, Torvosaurus is big enough to cause enough disturbance. A long, low rumble from the chest of the sentry has the whole herd ready for battle. Torvosaurus, however, is too late to run away. His brain is switched to attack mode.

In a few strides he’s only 20 feet away from the nearest target, a 30-foot juvenile. The Subadult panics, flounders in the mud.  In a few seconds Torvosaurus will be ripping her apart. Suddenly a black-striped whip slashes through the air.  Apatosaurus, like Diplodocus, Barosaurus, and Supersaurus has massive tail muscles, attached by winglike processes in the caudal vertebrae behind the hip. The tail tip moves faster than any insect or pterosaur, slashing Torvosaurus in the face.

Skin rips, muscle tears, and his very skull has a small but definite crack along the impact; Torvosaurus reels back in pain. This impact would have killed a Ceratosaurus or Marshosaurus, and even mighty Torvosaurus is so stunned he doesn’t pay attention to the Apatosaurus behind him as he staggers.  The neck of an Apatosaurus is also a powerful weapon, and many allosaurs attempting to rip out the throat wind up flattened by the strong, muscular body part.

This one hits with a 1,000 lb weight, which in itself is not enough to kill Torvosaurus. However, given the dinosaur’s already addled state and the slippery muddy ground, he slips and falls on his side. Muddy water splashes up feet in the air at the 3-ton impact of the falling predator. He’s not going to get up again; the Apatosaurus will not let him.

The Apatosaurus has moved up, the neck raised out of danger as he peers down at Torvosaurus. Then he steps on the hip of the fallen Torvosaurus. There’s a sickening crunch as the bone splinters and flattens at the impact. Blood from both face and neck pours into the water around Torvosaurus. Apatosaurus steps again; this time the other foot on the ribcage. His lungs and stomach are pancaked as the ribs crack with another disgusting crunch.  He has seconds to live, and already the oxygen and blood are leaving the brain. Apatosaurus isn’t going to wait. The third step is a hindlimb on the base of the tail, but the last is that first forelimb crashing down on Torvosaurus’ skull. The roar of pain turned to gasps is now silenced entirely.

Sauropods have short attention spans. As soon as the theropod hit the ground, the  herd lost interest. They move on, even the threatened juvenile as she returns to her feeding with the rest of them.  Coelurus dart into the forest of giant legs to scavenge the fallen giant as life returns to normal. Another predator will take its place, maybe another Torvosaurus, maybe an Allosaurus. The herd loses no members today-they may tomorrow, they may a year from today, but for today the victory goes to Apatosaurus.

The year goes on, the rains peter out and the heat eventually dries the wetlands. Torvosaurus retreat to the lake shore, but the sauropods are unruffled. The herds come and go, racing each other to the nearest forests.  The most successful, as always, are the Camarasaurus. They’re not the biggest sauropods, and their necks and tails aren’t as long as those of Apatosaurus and Diplodocus. However, their teeth are broad and their boxy skulls give them more powerful bites, allowing for quick food acquisition. The genus has been around for millions of years, and this species is the largest of them all. They travel from river to river and lake to lake, devouring anything in their path. At 75 feet, they’re much bigger than their previous species, but still not nearly as big as Supersaurus or Diplodocus.

They munch their way from grove to grove, nibbling on the fern prairies as they go. A volcanic eruption a few years ago left the ground ashy and black, wiping out previous greenery. However, now plants are taking advantage of the rich soil as it soaks in the retreating water. Within a few years a forest will return here. For now, the camarasaurs can still feast with their broad spoon-shaped teeth.

The volcanic eruption hit the animals, too. This particular herd has an asthmatic among them- an old bull who had inhaled the dust and never recovered. Sometimes he chokes on the stones he swallows for his gizzard. Sometimes he coughs in moist air. Sometimes mucus pours out of the nostrils. Still, as long as he can keep up and feed with the rest of his kin, he’s fine.

Right now he’s spotted a forest nearby, one that wasn’t hit by the eruption and is fed by a freshwater stream connected to lake T’oo’dichi.  He sniffs the air-there’s already some dinosaurs there, but none are large and the nearest sauropods, a group of Supersaurus, are still some hours away. Sauropods have horrible vision-their eyes are tiny and wide-set.  Their colors are more faded, except for their necks and tails like a Brachiosaur’s maroon throat or an Apatosaur’s stripes (red in exelsus, white in ajax, and black in louisae). The Camarosaurs have blue-grey bodies with dark patterns on the back, but the sexually active have red noses. His nose is fading but still distinctly crimson-he’s past his prime but still has a season or two left.  He mated just a few weeks ago. If he’s lucky he’ll mate again next year.

That’s a big if, however. Prowling the other side of the treeline is the biggest predator of the Jurassic. Torvosaurus and Allosaurus must defer to her. Her kind is rare, but even the well-armed Stegosaurus and giant sauropods flee at her scent.  She is a Saurophaganax maximus, the biggest carnosaur yet. In the Cretaceous we’ll see her like again, but once the species goes extinct it will take millions of years for predators to reach her size again.

She’s big; 43 feet from her light green snout and red head crest to the very tip of her tapering tail.  She’s covered with scars-if there’s a dinosaur species in her lifetime, she has a scar from it. The smallest scar is a tiny, almost indistinct gouge on her thigh from her youngest days tussling with a Drinker.  The largest is a long scar running along from hip to head from a tail slash from a Supersaurus.  The last scar received is a bite mark on her arm-she scattered a trio of Allosaurs from their Stegosaurus kill last month. One savaged her right forelimb; she tore out his throat and had him as the next day’s meal.

The dry season will see her take on healthy dinosaurs and more fights with carnivores over rarer game, but it’s just wet enough for Saurophaganax to have a choice of prey. She could try at the Drinker herd or Uteodon family nearby, or even one of the armored Mymooropelta that have crowded near the river. But she smells sauropod. Her sense of smell is even keener than her prey’s, and the wind is on her side.   

She can’t smell that one of the Camarasaurus is weaker. She finds that out during the attack.  Saurophaganax is not intelligent enough to coordinate an attack, but she understands flanking. She’s old enough to have learned how to approach prey-she’s missed enough meals to learn how not to. Experience and instinct bring her walking around the forest. She’s leaving the denser brush to maneuver, but keeping her distance. She’s going to put herself on the far side of the Camarasaurus.

The Camarasaurs, meanwhile, march to the forest. Their hunger drives their long strides to move surprisingly fast, and they begin to chow on the conifers. The Drinkers and Mymooropelta initially scatter but they soon realize that their new neighbors aren’t predators and so cluster around the sauropods to feed on the falling greenery.  They can’t reach the treetops, so they associate with the giants in order to feed on their scraps. They even have developed an association mentally between the sauropods and foliage.

Saurophaganax has yet to feed. She’s coming in slowly from the side of the forest. She peers through the trees at the giant shapes until she’s clear. Once she’s clear of the trees, however, she’s exposed. She’s got precious seconds to spare. Her best hope is the wind not to betray her and the sauropods to stay at their brunch.

The wind cooperates until she’s only a hundred feet away. It shifts, and the scents turn. Suddenly the Camarosaurus can smell the predator. The old bull sends up an alarm. He’s been attacked many times; he’s killed a fair number of foolhardy Allosaurs. All big predators are given as much respect as possible, and the bigger the threat the greater the fear.

The other herbivores hear the cry and then smell the attacker, and react. The Mymooropelta make for the brush. They’re well armored and can even repel an Allosaur with their sharp spines, but they still don’t want to fight, especially with an opponent that big.  The Drinker bolt and scatter for cover-their greatest weapon is their speed and agility. On the plains Ornitholestes and Dryosaurus can outpace them, but in the rivercourses and forests they are master. They could run circles around Saurophaganax; right now they’re just trying to run away.

The Camarasaurus are confused. They aren’t experienced with Saurophaganax, so they don’t know whether to charge or hide, to make to the plans or the forest.  The youngest crashes into the brush at top speed; its mother rears up on her hind legs to threaten the carnivore. Several run along the side of the forest-others flee to the open.  Their giant hearts beat faster, their breaths become deeper and faster. Adrenaline spikes, pulses race-they’re on the alarm.

It’s the best way to induce an asthma attack…and the worst time to have one. The old bull wheezes in mid stride to a clearing-he’s trying to find a defensible spot, one big enough to maneuver. However, his lungs spasm and shudder.  Oxygen flow is stop-start, and that’s the worst thing possible for an animal with a 20-foot neck.

Sensing weakness in his movement, Saurophaganax targets the old Camarasaurus. A few strides bring her closer. He swings his neck as a flail, managing to cough out a roar. Saurophaganax pauses to roar back then changes direction to flank him. He sees her move, begins to pivot to meet her. His tail crashes into the undergrowth, splintering branches, sending pine needles flying, and sending a conifer crashing into the ground.

He rears up and crashes back down to threaten her. She just sidesteps again.  He tries to rear up again, but coughs and staggers back. He regains his breath in time to set down his front feet and stumbles backwards. This smashes and knocks down more trees as his hind feet and tail ravage the forest.

The noise just disorients Camarasaurus more, and he tries to make a break for the open ground away from the forest.  In his panic, he’s not aiming for Saurophaganax, but barrels right past her. This is her opportunity-she takes a few steps backwards as he begins the charge and pivots backwards and to the left as he approaches.

She makes her move as he passes, then pounces. She’s 4 tons to his 50, but she’s not using just her weight. Saurophaganax sinks her claws into his side as she turns alongside Camarasaurus. Her jaws are already wide open-she doesn’t have a bone-crushing bite, but can pierce bone with sheer momentum. Her powerful neck slams her mouth against Camarasaurus, the curved serrated teeth slashing into his back and side. He slams his tail against her, but not with enough force to knock her over. Instead the carnosaur stumbles backwards, ripped free of her prey. She’s evolved to take this into her strategy-the claws are sharp, curved hooks on strong arms, the teeth slash like swords, and both leave long, deep wounds as she is dislodged.

She was aiming for the back of the shoulder, but missed it by a foot. If Camarasaurus was healthier, he’d recover, fight back more effectively, and might escape. However, his condition leaves him weak. She’s not discouraged-Saurophaganax knows he’s weak. She will take him down. Before he can catch his breath and turn around, Camarasaurus is attacked again. This time she ducks her head under the tail, turns it sideways, and bites into one of his hindlimbs. Camarasaurus roars in pain, and kicks backwards; again Saurophaganax is dislodged, but she’s not hurt. Her weight allows her to roll with the punches and only be stopped.

This time Saurophaganax goes wide. Camarasaurus tries to pivot to meet her, but he’s too wounded to move fast enough-his breaths are shuddering and the blood loss makes him dizzy. She charges again-this time her jaws hit the juncture of his high shoulder and his thick neck while the claws dig in once more.  He stomps his right forefoot, but her teeth and claws are sunk in. In a wild frenzy, he slams his neck against her. The flailing head rams into her stomach as he pushes himself backwards with still-strong forelimbs.

For the third time, she stumbles backwards, repulsed by his defenses. It’s still not enough, and it will be the last time-Camarasaurus is staggered backwards as well. Saurophaganax sees him teeter as his injured hind leg collapses, and makes one last charge. This time she’s not repulsed. This time she’s going in for the kill. This time, the teeth and claws sink into the previous wounds on the neck and chest, going deeper.

Weakened, bleeding out, exhausted, Camarasaurus lets out a last deep bellow as he collapses onto his side, pulled down by the giant predator. The earth shakes at his fall, but Saurophaganax doesn’t let go with her claws. She rips out the flesh that her jaws manage to capture, swallowing it whole. She continues to rip into the base of his neck, severing arteries, slicing blood vessels, carving up muscle.  His windpipe, quaking and spasming for the past few minutes, finally stops moving as Saurophaganax’s teeth cut it in half. It only takes a second before the neck and head stop moving entirely. No more pain from coughs, or from the blood-stained weapons of his conqueror-Camarasaurus passes into blackness.

Saurophaganax will eat most of the carcass-no other predator can scare her off her kills. Her teeth aren’t evolved to crush bone, however, so they will be picked clean by Coelurus and other predators. No predator kills every day, so they must make the most of their kills. Saurophaganax will hunt again, but not for a while.Now she’s got 50 tons of red meat to eat.

She eats the Camarosaurus for most of the week, and  feeds on carcasses and small game like Uteodon and juvenile stegosaurus for the next few weeks.  Even an unlucky Ceratosaurus provides a welcome meal. By the next month, however, she needs to kill another sauropod. Big game is a gamble; dangerous and difficult, but it’s worth the danger if it means having the next few days to yourself.  Saurophaganax sometimes has had to wait weeks for another meal, having to run on her hundreds of pounds of stored calories. She’s warm blooded, though, and so Saurophagnax burns through them fast. Now she’s hungry again.

Apatosaurus is hungry too, and he moves with his herd from forest to forest. The dry season has not yet begun, so every herbivore is packing on the pounds to get them through the lean parts. Right now his herd is moving with some Supersaurus. They evolved from an earlier Apatosaurus species, and now they rub gigantic shoulders in this age. They’re not alone-Mymoorapelta and Dryosaurus tag along, the ornithopods scouting out the front. Ankylosaurs bringing up the back, weaving their way around the giant dung piles left by their titanic companions.

Saurophaganax can hear them miles off through the pads in her feet. The pounding of the multiton feet crushing the fern prairie and dry mud flats can be heard hours before they arrive at their destination. All she has to do is be still and hope the tree cover and wind won’t betray her. So far, so good. Sometimes her luck turns against her and the prey spook. Hopefully, this time Saurophaganax will be lucky.

Hopefully for Apatosaurus, this time she won’t. It’s hard to stalk this kind of herds-the Dryosaurs have excellent vision, and the Mymooropelta have an excellent sense of smell, and usually group together. The sauropods provide dozens of tons of muscle, each capable of routing an entire pack of theropods. Adult Supersaurus don’t have natural predators-if they make it to full size and find enough food to sustain them, they are impregnable.

Apatosaurus feels safe.  The Torvosaurus he crushed earlier in the season wasn’t the first attacker. As a youngster, a Ceratosaurus ripped open one of his thighs, and only a desperate kick shattered the attacker’s ribs. Every species of carnivorous dinosaur has taken a bite at him, but he’s been lucky so far. Of his siblings, only two remain. The rest have been devoured. He’s 47. If his luck holds, he’ll make it to a full century. It’s a monotonous life most of the time, but monotony is good if the alternative is terror. His brain’s not big enough to need the stimulation, anyway.

Right now, his brain’s telling him to eat and drink. He’ll need dozens of gallons of water and many tons of vegetation. He’s got a slower metabolism than the ornithischian companions thanks to his great size losing heat slowly, but the great breaths and heartbeats he takes need a lot of fuel. Naturally, he can smell water and plants from far off like most of the animals here.  The first one to smell the food begins the march, and soon others follow. It was a Supersaurus that first smelled the forest, and the dozens of dinosaurs follow. Usually they browse in segregated herds but once an area is defoliated every herbivore clusters around the available food.

Of course, that makes them ideal places for ambush predators to lurk. With her size, Saurophaganax can’t move as fast as the Allosaurus and Ceratosaurus. They hunt smaller, faster prey. She’s a specialist, a professional giant slayer. That means hiding in forests and picking off the vulnerable prey.  Even if they’re 70 foot long sauropods.

Unfortunately for her, the first prey to approach is the Dryosaurus. They fan out and eat the undergrowth. They’re not worth it-they’re too fast, too small, not worth the calories she’d use in catching them even if Saurophaganax could.  Now the Supersaurus arrive. They reach their long necks high into the canopy, raking off the leaves with their teeth as soon as they can reach them.  Apatosaurus make their way off to the side; there’s enough trees for both these herds, at least for now.

Soon, the entire herd has spread out to feed. Conifer needles, even the biggest, well-watered ones, are tough and low in nutrition. The sauropods, however, have giant stomachs filled with stones and hydrochloric acid. Ground to paste, the vegetation will be sent though a hundred feet of intestines and every last bit of nutrition will be extracted. Brontosaurs are walking reapers and mills combined into one. Their efficiency has made them the most successful herbivores on the planet.

Saurophaganax still waits behind a screen of greenery. She smells and hears the herd of course, but they’ll have to get closer before she can pick off an individual. A Mymooropelta shuffles nearby. Ankylosaurs are too crunchy-all she’ll get is broken teeth and little meat to show.  No, she’ll wait for the sauropods.

Here come the brontosaurs; the first clue is the sound of crashing trees as they push over the dead sequoias to get at the live ones.  The juveniles follow the adults-as the dead trees fall, the saplings and cycads are exposed to their hungry mouths.  They’re ideal predator targets, but the adults provide a titanic barrier. Apatosaurus might have his own offspring behind him. He doesn’t know or care.

The juveniles, however, are being carefully watched by Saurophaganax. She’s not going to charge right now, but the moment they wander off from the rest of the herd, the moment they’re closer to her than they are to the adults…..Yes, they’re only a few meters to striking range. Her instincts react to a predicted sequence-prey comes into range, attack, kill, feed. It’s a basic reaction, but one that has worked for over a hundred million years of predator evolution.

They get closer. They’re only a few meters away from ambush. Each step the small group of juveniles takes, brings them towards the danger. Saurophagnax’s instincts accelerate. Her heart beats faster, blood sent to her legs and head. Her nostrils flare, taking in the scent of the prey. Muscles in her legs begin to expand and contract, taking steps towards the clearing where the sauropods browse. She doesn’t notice Apatosaurus moving towards the crèche of juveniles.  It shouldn’t matter-if the nearest youngster keeps moving in its path, it will be over in second.

It doesn’t. Its small brain is impulsive, with barely any attention span. This one clicks from the saplings masking Saurophaganax to a group of ferns a few meters away.  Saurophaganax has already blown her cover-she’s already broken from the treeline and exposed her position. The juvenile isn’t close enough for her burst of speed, but it’s too late; she’s in the open.

Apatosaurus sees her. A loud roar pierces the air-an eerie combination of nasal moan, deep-chested rumble, and angry growl. The sound of an angry sauropod is one of the most terrifying sounds. Saurophaganax responds in kind in frustration. She seldom roars at herbivores, saving it for her smaller predatory rivals. Noise just frightens off the prey. But this time frustration hits her and she turns from cool hunter to enraged banshee letting loose a deafening deep hiss.

It’s standoff-Apatosaurus rears up and crashes back down, while Saurophaganax snaps its jaws and flashes its head crests.  It’s not a situation that either has been in-usually either Apatosaurus’ attackers have gone straight to the offensive or fled, while Saurophaganax’s prey have either turned tail or been brought down. Neither has an instinctive reaction for this-the standoff does not compute.

Apatosaurus’ attention span is smaller-his is the first mind to change. When Saurophaganax fails to move forward, he assumes the fight is over and turns.  His neck curves towards the predator but the rest of the body makes an 180 degree turn. That’s when Saurophaganax attacks.  She heads towards the back of his thighs-if she can tear one apart, he’ll go down fast.

She doesn’t get that far-there is a blur of movement and a small sonic boom as the tail whip of Apatosaurus lashes out.  It’s only a glancing blow, but it cuts open Saurophaganax’s face. The whip communicates one thing: keep your distance or suffer worse.  In her youth, Saurophaganax has had a taste of the lash; she knows what she risks. She saw a littermate killed when the lash cut his throat and broke his neck.

Her rage cools-she’s still going to kill him, but now there is strategy. Saurophaganax pulls far right, within tail range but not for long. Now they’re parallel, glaring back at each other. They don’t have to turn their heads to see-both have wideset eyes granting them a wide field of vision. Apatosaurus flicks the tail again, but it’s a threat, not an attack. Saurophaganax doesn’t blink.

Instead, she goes for the kill. The giant predator charges in towards Apatosaurus’ neck, hoping to sever it.  Seeing the attack coming, Apatosaurus pulls his neck back to avoid the blow. Saurophaganax misses it by inches, the teeth almost grazing the skin of the neck. The momentum causes her to overshoot her target, putting her head in range of his counterattack. Apatosaurus swings his neck like a flail, swatting her back, and shoulder checking her body. An Allosaur would be flattened and trampled.

She’s not an Allosaurus, however. She just walks backwards, snapping her jaws in case of more neck swipes. She tries to get another angle on the neck, sidestepping to the right. Now they’re facing each other once more, but at close range.  She feints as his neck again, making him raise it in response.

Saurophaganax is seconds from concluding the attack; all she needs to do is get a good bite on the neck or body. She steps forward, he steps back. Another long stride by Saurophaganax brings her close in-another lunge and she’ll have him. Apatosaurus responds by rearing up and bringing his throat high out of harms way.

Saurophaganax leaps up for one last chance at the throat-she is met by a slash of his left foot claw. Each of Apatosaurus’ front feet is armed with a large, curved claw, used to scratch at rivals and adding a blade to his crushing feet. It’s not a direct hit-it slashes the front out her snout, adding another cut to Saurophaganax’s face.

Saurophaganax isn’t done yet, though. As she withdraws from that clawed feet, she notices his chest and stomach are now wide open for attack. She can still rip him open. She lunges forward again.

And Apatosaurus comes crashing down. The same foot that cut the theropod’s face now comes down on the back on her head as Saurophaganax steps forward to bite. The falling foot brings the giant predator’s head down to earth. She roars in surprise and pain as both dinosaurs fall down.  When a 25-ton dinosaur steps on the back on your neck, you’re out of the fight. Surprise is Saurophaganax’s last emotion-she never saw it coming.

Her skull is intact, but the vertebrae behind it are history. The spinal chord is pancaked in a 2-foot stretch behind the head of Saurophaganax. Her entire nervous system is shattered as she goes into shock-the heart stutters, her lungs swell briefly then release as paralysis takes over. The apex predator of the era asphyxiates under the foot of her prey.

Just as the soggy battle with Torvosaurus, Apatosaurus moves on. He peers down at the crushed predator from 30 feet in the air; she doesn’t move. Apatosaurus gingerly steps off the broken neck of the predator, and this time correct in his assumption, walks back to the herd, regrouping in the shade of the redwoods.

In the long term, the diplodocids will die and it will be the descendants of Camarosaurus and Allosaurus that will rule. Saurophaganax is simply the first in a line of giant sauropod killers, big game hunters that shred their prey with razor teeth. However, the career has a high risk factor, and today we see one. It’s not the orange-sized brain that carries the day, but the 75 tons of pure dinosaur.  This is the era of the brontosaurs. It will be the flower, not the fang, that will topple their dynasty.

Next week, we cross the pond and jump forward in time to see the Carnosaurs continue their reign as the herbivores change their guards.