Acrocanthosaurus
Begin with a square, white side up, with both diagonals precreased.
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180°
Valley fold the lower left side to the horizontal center line, bisecting the angle on the left corner, but crease only where the fold intersects the lower right side. Unfold.
Valley fold the bottom corner to the center of the square, again creasing only on the right side. Unfold.Valley fold the bottom point up so that the intersection of the edge of the paper and the angle bisector from Step 1 (circled) lays on the crease line from Step 2. Rotate the
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Reverse fold the top sides in to the center line, creating a small preliminary base at the top. The next diagrams are enlarged.
Valley fold the sides of the preliminary base at the top to the centerline and unfold.
Petal fold on the creases from Step 5.
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8.
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Valley fold the petal back down.
Valley fold the lower edges to the center, bisecting the lower point on each side, and unfold. Because of the proportions used in Steps 1-3, the side corners of the paper should lie right at the lower tip of the petal fold from Steps 6-7.
Valley fold the top point (including thebird base assembly) down along a line that connects the tops of the angle bisectors from Step 8. This crease should go across the very tip of the petal fold. Unfold.
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90°
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Valley fold the entire model in half, right side over left. Rotate the model 90° counterclockwise (the thick point including the petal fold will be on the left).
Valley fold the thick point at theleft down to the bottom point and unfold.
Valley fold the thick point at the left down to the intersection of the edge and the angle bisector from Step 8 and unfold.
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Double reverse fold the thick, left point inwards on the crease from Step 11 and back out on the crease from Step 12.
Valley fold the upper part of the paper (including the upper part of the thick, petalfolded assembly inside) as far upwards as it will naturally fall.
The result. Unfold the top flap back down.
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Turn the paper over from side-to-side.
Fold the top flap up again, as in Step 14.
Turn over from side-to-side. The next diagrams are enlarged.
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20.
Valley fold the left half of the model (top flap only) over the right, creating a vertical lineconnecting the top and bottom points, and unfold.
Squash fold the left hand part of the upeprmost flap to the right. The lower left point of the fold lies where many layers are locked together.
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22.
Valley fold the top flap at the lower right of the squash to the vertical central line and unfold.
Swivel fold on the crease you made in Step 21. An additional valley fold will be madethat connects the corner at the lower left and the upper end of the crease made in Step 21.
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Wrap the small flap on the surface underneath.
Valley fold the topmost flap on the right over to the left, incorporating a rabbit ear in the triangle.
26. 25.
Unfold the flap and rabbit ear from Step 24. Turn the model over side-to-side.
Fold the petal at right back up along theexisting crease.
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The loose colored triangle that lies on top of the point at the bottom is connected to some paper that is currently trapped inside the model. Grabbing the circled points, pull them gently apart and away from each other to expose it; in doing so, the upper half of the model will also swing up.
Pull out the trapped layer of paper, wrapping it around the raisededge at the lower right (this is a diamond-shaped layer of paper when unfolded; as you do this, or unfold it, unwrap the paper, and refold it). The freed paper at the bottom of the petal fold at right (circled) will swing up. This is a difficult move.
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Now the rectangle of paper is free, and sticking up in this diagram. Flatten the model by pushing the freed flap and the points to…