hen above the mountain…top appeared the silhouette of a second giant bird…thing。
49。 PREHISTORIC SHORE
After a hundred years of collecting specimens； we have but a small record of the vast dinosauria。 How many thousands of other forms might have existed； we will never know。
…K。 Carmen Sontog； Nature's Lost Species
Warm Springs Indian Reservation； Oregon
POSTQUILT： TUESDAY； 4：25 P。M。 PST
Petra stood on the limb and leaned out； one hand firmly grasping the overhanging branch。 She could see through the leafy overhang； but couldn't see why the dinosaurs were reacting。 In the herd； the pickets were moving。 The large males on the forest side of the herd were pawing the earth； while those along the lake side were trotting to take position next to their brothers。 Finally； the large males were spaced evenly along the side of the herd facing the jungle。 The females formed a ring within that； encircling the calves。 Petra was impressed with their instinctive wagon…train behavior。 The males made a formidable barrier with their long snouts and collar horns； and their huge bony collars。 The females made an equally impressive wall； standing shoulder to shoulder to protect the young。 Petra couldn't imagine a dinosaur that would dare attack such a defense。
A crashing sound drew her attention to the brush。 Something was moving through the brush recklessly； heading straight toward the herd。 Petra held her breath； waiting to see the source of the ruckus。 Suddenly it broke into the clearing at a dead run。 It was Colter。
Petra laughed out loud。 She shouted his name； happy and relieved at the same time。 Colter was only a short distance across the clearing when he saw the dinosaur wall ahead of him and he turned； angling toward the clump of trees。 Petra shouted to him again and waved her free arm。 Colter seemed oblivious though； and kept looking back over his shoulder。 Petra followed his glance back to the brush。
Then she nearly lost her grip。 ing through the brush was the biggest dinosaur they had seen yet。 It towered above the vegetation； walking on two huge back legs； and had a massive head with immense gaping jaws。 Loud enough for Dr。 Piltcher to hear； she said； 〃I don't think we climbed high enough。〃
Petra was afraid to shout now and instead prayed silently that Colter would make it to the trees。 She watched the race in silent horror； images of Dr。 Coombs's ravaged body drifting through her mind。 The monster was in single…minded pursuit of Colter and seemed oblivious to the monoclonius in their defensive position。 Colter was losing the race and Petra knew it would happen soon。 The dinosaur would lean down and snap Colter up； swallowing him down in two bone…crushing bites。 Petra couldn't watch； and she started to look away； unprepared to lose two friends in one day。 Then Colter bolted left。
Colter ran right toward the circled monoclonius。 The pursuing dinosaur heeled over and followed； its tail swinging through the clearing； throwing up turf and dust。 Petra screamed at him。
〃No； Colter； no！ They'll kill you！〃
Petra could see no hope for Colter now； but she was riveted to the scene。 The monoclonius pickets were closing ranks； the males ing shoulder to shoulder； their heads down； ready to impale the threat。 Colter raced on； the pursuing dinosaur gaining。 He was trapped between a wall of horns and a set of jaws well practiced in bone crushing。
But Colter didn't slow。 Instead he hit the wall full speed； squeezing between two of the large males and out behind them。 Then he turned； avoiding the wall of females； and raced between the males and females； curving around to the end of the picket line； and then out toward the clump of trees holding Petra and Dr。 Piltcher。
The pursuing monster pulled up just before the horns of the males； who stood their ground； prepared to take the full charge of a carnivore with twice their mass。 The monster screamed in frustration； blasting its breath at the monoclonius； who stood silently but defiantly。 Suddenly； one lowered its head and then charged forward； thrusting its horns up at the monster's side。 The newer turned left to avoid the charge； screaming in rage； but another monoclonius charged forward； jabbing it on the right。 The monster trumpeted in pain this time； but backed up and then began walking along the defense line； looking for an opening。
Petra watched Colter run into her clump of trees but lost sight of him when the leaves obscured her view。 She yelled to him again； but the roars of the dinosaurs drowned out her voice。 Turning back to the standoff； she saw the monster walking along the defensive line toward her tree。 Suddenly she felt naked。
〃Dr。 Piltcher； we've got to climb higher。 Now！〃
Dr。 Piltcher struggled to his feet； and reached for another limb。 Even though the limbs were smaller and closer together at this height； Dr。 Piltcher had only half of his normal strength。 The dense foliage made it hard for Petra to help him。 The best she could do was lean into the trunk from her side and steady him with one hand while he tried to pull himself up。
The monster was continuing along the picket line； which moved in front of it to keep the largest males in front of the enraged carnivore。 It paused to roar at the monoclonius occasionally but made no attacks。 It was close to their tree now； and Petra signaled Dr。 Piltcher to freeze while it passed。 Its head moved along the treeline at eye level； and Petra found herself mesmerized by one huge eye。 How could something that big be alive？ But it passed and Petra watched its back move toward the lake and to where Colter had disappeared。 Whispering a prayer for him； she signaled Dr。 Piltcher to try again。
When the giant carnivore reached the lake its frustration boiled over。 Obviously； there was no opening in the line of monoclonius； only a solid line of horns and armor。 From experience； it knew the three horns could be killed； but only if caught alone。 In a pack they worked together； jabbing over and over； and exposing nothing to the carnivore's jaws except horn and bony collar。 But the giant's hunger was great today； almost as great as its frustration； so it screamed again and then charged。
The carnivore's scream nearly shook Petra from her limb。 She could hear its rage。 Petra turned to see the carnivore thrust down； clamping its jaws on the collar of one of the monoclonius； its teeth squalling on the bone like fingernails on a black board； and Petra flinched。 The monoclonius roared back defiantly； trying to shake the carnivore from its collar； but the massive jaws kept their grip and the carnivore jerked the monoclonius briefly off its feet。 。
The monoclonius roared again； but in anger； not in pain。 Petra realized there were probably no nerves in that protective collar。 Suddenly another monoclonius shot forward； burying it： snout horn into the thigh of the carnivore； and then quickly pulled out and backed away。 As the carnivore's jaws released and its head snapped up and turned toward its tormentor； another male jabbed it from the other side。 It trumpeted in pair this time； snapping its head toward the new threat。 Again it was attacked from its left。 Petra silently cheered the monoclonius。
The carnivore； bleeding from the thigh wounds； began backing up； bellowing out its pain and outrage。 Now the monoclonius advanced slowly； heads down； pawing the ground threatening the carnivore every step of the way…Petra realized it was backing straight toward their tree。
She turned to signal Dr。 Piltcher to freeze only to find him hanging upside down； with one leg over the overhanging limb trying to get still higher。 Petra turned to see the back of the carnivore's head ing toward her。 Yelling for Dr。 Piltcher to hang on； she wrapped her arms around the trunk of the tree and buried her face in the bark。
At the last second； the carnivore turned and backed into the tree next to theirs。 With nowhere to go； the monster bent and snapped its jaws at the advancing monoclonius； who stopped their advance and backed away。 When the monoclonius had given it enough space to retreat； it released its anger in another deafening roar； and then turned…spotting Petra and Dr。 Piltcher。
Petra's strength melted away when the giant's eye fixed on them。 Then the head turned； showing both its eyes； and its huge flaring nostrils。 The head leaned into the tree； snapping off limbs in its way。 When Petra saw the jaws opening slowly she turned away； and jumped to a limb below。 She caught it； but her weight pulled her free； and she fell again。 She hit another limb with her hip； ricocheting off and onto another。 This time she wrapped her arms around it and managed to hold on。 Her legs were still dangling； but she looked up。
Dr。 Piltcher had dropped back to the lower limb and was standing facing the monster's head； flinching back； turning to jump； when the jaws reached him。 They crushed both the professor's feet and the limb。 Dr。 Piltcher screamed and fell headlong； his ankles still trapped in the jaws。 With a mighty shake of its head； the professor was thrown to the ground。 Still he remained conscious and lay screaming； his ravaged legs spurting blood。
With more terror than she'd ever felt； Petra turned away when the dinosa