Step 1:
The other side of this paper is white, prefold over this line.
Then turn the paper.
                                               

Step 8:
Mountain-fold over this line, do the same on the other side, see arrow.

Step 6:
Valley-fold in half, don't press the model completely flat.

Done!

Step 10:
Lay the model on the table or another hard surface. Then bend/fold/push the model in the direction of the arrows.

Step 9:
Push the corner inwards by making a mountain-fold over the two outer lines and
a valley-fold over the line in the middle.
Do the same on the other side, see arrow.

Step 5:
Valley-fold over the short line on the left.

Step 7:
Push the head to the right by making a valley-fold over the two lines on the right and a mountain-fold over the two lines on the left.

Step 3:
Valley-fold over these 2 lines.

Step 2:
Valley-fold over these 2 lines.

Step 4:
Valley-fold over these two lines.

The Mosasaurus belongs to a dinosaur group which lived in the ocean. The Mosasaurus ate meat only,  like fish, sharks, shell animals, birds and even their own kind. The average Mosasaurus was about 20 feet in length, the longest ever found was 45 feet long.