Scarab beetle by Fumiaki Kawahata

 From Fumiaki Kawahata's Origami Beetles of the World.

Maple Leaf 2 by Takuji Sugimura

 From Takuji Sugimura's Origami Greetings.

Stegosaurus by Yoshihide Momotani

 One square of gold foil-backed paper. From Yoshihide Momotani's Origami Dinotopia.

Regular tetrahedron skeleton by Tomoko Fuse

 Made with 6 squares. From Tomoko Fuse's Three Dimensional Karakuri (Origami Land). (Not sure of the translation; another source calls it "Three Dimensional Trick-Unit Origami". I thought "karakuri" were Japanese automata.)

Cruising Boat by Yoshihide Momotani

 Made from a 2 x 1 sheet of paper. From Yoshihide Momotani's Origami Ships.

Modern Cube by Kunihiko Kasahara

 Made with two squares (one a little smaller than the other). From Kunihiko Kasahara's Origami Discovery 2: World of the Cube.

Sunflower by Tomoko Tanaka(?)

From Tomoko Tanaka's Origami Shikishi Hundred Flowers ["shikishi" = colored paper?]

Center is made from a separate square of paper.

 I'm unclear about the authorship of this model and book. I think it's either jointly authored by Tomoko Tanaka and Makoto Yamaguchi, or else Yamaguchi was the editor. (Yamaguchi owns "Gallery Origami House," the publisher.)

Bulldozer by Yoshihide Momotani

 From Yoshihide Momotani's Origami Vehicles.

Tachypleus tridentatus (Chinese horseshoe crab) by Fumiaki Kawahata

 From Fumiaki Kawahata's Dinosaur Origami 2 (yes, this is a Korean translation of a Japanese origami book).

Persimmon by Tomoko Fuse

 From Tomoko Fuse's Origami Gifts. (Two back-to-back sheets used to achieve two-color effect.)

Mermaid by Fumiaki Kawahata

 From Fumiaki Kawahata's Origami World Fantasy Animals. (Made from two squares.)

Sphinx and Pyramid by Fumiaki Kawahata

 

From Fumiaki Kawahata's Origami World Fantasy Animals.