During the Carboniferous period, insects were monstrously large. There was Meganeura monyi, a giant griffinfly* with a two foot wingspan, and a 7 foot long millipede relative called Arthropleura armata, to name a couple. The main reason that they grew so large, simply put, was that a higher percentage of oxygen in the atmosphere allowed the young to grow bigger, resulting in larger adults.
So here I have made 3 models of Carboniferous insects.
The first is Pulmonoscorpius kirktotensis, which was a giant** scorpion. The model I have made is life sized, and includes a base designed like the scorpion's habitat, with a sort of rock area, 2 shrubs/saplings, and lots of grass and weeds. The tail, legs, and chelicera of the scorpion are all posable, and the animal itself is mounted on a turntable.
Second is Meganeura monyi. This model is also 1:1 scale, and consists of a fairly flat baseplate with a tree stump as a perch for the Meganeura. The griffinfly itself is held up by a few sturdy transparent pieces in a lifelike*** position for landing. The wings and legs are posable. This was one of the hardest bases to make, because of the stump****, but I am very happy with the results.
The final model here is, ironically, the first one I made. It is the 1:7 scale model of Arthropleura armata, the giant centipede/millipede relative. This is the most detailed base, with a (scaled down) tree, an underwater section, and underwater animals. The Arthropleura itself is an example of simple design, great look, using hinges and slopes to achieve a smooth insect shell look. Each of its many legs are posable, and so is its body, although I have set it in a "rearing up" position that I saw in reconstructive drawings.
I think that this would make a great set because it is educational, and can bring attention to prehistoric animals besides dinosaurs. I built it because my two favorite things to build from LEGOs are ocean animals and anything from the Paleozoic era.
Piece count: 2,968
*Griffinflies are extinct relatives of dragonflies.
**Giant being about 1 1/2 feet long.
***Which I based on modern dragonflies.
****I actually used the same technique here as I did for the ammonoid shell.