That's it for the guides! From this point on, press harder with your pencil for a more defined drawing.
Step 6: Inside the head, on the top, left side, near the top jaw, lightly sketch a small circle for the Ichthyosaurus' eye. When you get the size and position of the eye right, darken the shape but make the sides a bit pointier. Inside the eye, off to the side, draw a tiny circle for a highlight. In the middle of the eye, draw a bigger circle and shade it in for the pupil. Shade the top of the eye lightly to make it rounder. Above and below the eye, draw a curved lines for the brow and some wrinkles.
Step 7: Darken the thin, triangular shape on the top, left side to create the Ichthyosaurus' top jaw. Make the shape a bit thinner than the initial guide and curve tip more. Continue to draw the line at the top, along the initial circle to create the head. Along the bottom edge of the jaw, draw a series of tiny, V-shaped lines for the teeth. At the top, near the eye, draw a small oval for the nostril.
Step 8: Darken the thin, triangular shape at the bottom, for the Ichthyosaurus' lower jaw. Make the shape of the jaw a bit thinner than the initial guide. At the top, draw a series of tiny triangular shapes for the teeth. On the top edge of the lower jaw, draw a curved line for the tongue. On the right side, draw a couple of short lines to emphasize the jaw.
Step 9: Darken the triangular shape on top of the body for the Ichthyosaurus' dorsal fin. Curve the lines a bit more as you darken the shape. Darken the shapes under the body for the pectoral and hind fins too. Make the top lines longer so that the bases of the fins are inside the body. Curve the lines or the tops of the fins so that the bases are thin.