Three hundred million years ago, over the swamps where France stands today, an insect with a wingspan of nearly seventy centimeters hunted through the air. On the forest floor, a relative of the millipede stretching more than two and a half meters dragged itself between giant trunks. Millions of years later, in China, pigeon-sized dinosaurs glided on bat-like membrane wings, and a furry, flat-tailed animal dived after fish in a Jurassic river. None of them appear in movies. Almost none have names known outside museums. And yet each one once owned a piece of the Earth.

This documentary reconstructs those lost kingdoms. You'll understand why Carboniferous insects grew so enormous — in an atmosphere that may have reached 35% oxygen — and why the oxygen story alone doesn't explain everything. You'll meet Meganeura, Arthropleura, and the head that was only revealed in 2024, and see how the sky was conquered by reptiles that never even flapped their wings: Weigeltisaurus, which glided on bony rods jutting from its sides, the Triassic gliders, and Sharovipteryx, whose main wing surface was on its legs.

The film shows that feathers appeared long before flight, with the four-winged Anchiornis and Kulindadromeus, a herbivore covered in fuzz — and tells the story of nature's failed attempt to build a bat-dinosaur, with Yi qi and Ambopteryx. It also reveals how the first birds took the sky away from giant insects, through a survey of more than ten thousand fossil wings that pinpointed exactly when insect size stopped tracking oxygen levels.

The second half belongs to the small creatures that lived in the shadow of the dinosaurs — and weren't quite so small in the ways they made a living: Castorocauda, a swimmer with a beaver-like tail; Volaticotherium, a furry glider; Fruitafossor, a digger; Repenomamus, which ate baby dinosaurs; and Didelphodon, with one of the most powerful bites relative to body size. You'll see the survival tools that kept them alive — burrows, torpor, one-time tooth replacement, sharp hearing, a venomous spur, and fur — the Brazilian research on Brasilodon from Rio Grande do Sul, and Juramaia, the oldest known relative of placental mammals. And you'll discover that none of these kingdoms truly disappeared: they're scattered across the world today, in the wing of a dragonfly, in the song of a bird, and in the bones of your own ear.

CHAPTERS

00:00 Introduction
02:12 1. The Sky of Giants
11:57 2. Wings Made of Bone
19:22 3. Feathers Before Flight
24:42 4. The Sky Changes Hands
29:57 5. The Small Ones in the Shadows
36:23 6. The Weapons of the Small
44:58 7. The Mother of the Jurassic
49:32 8. The Kingdom That Remained

REFERENCES

Clapham, M. E. & Karr, J. A. "Environmental and biotic controls on the evolution of insect body size." PNAS, 2012.
Davies, N. S. et al. "The largest arthropod in Earth history: insights from newly discovered Arthropleura remains (Serpukhovian Stainmore Formation, Northumberland, England)." Journal of the Geological Society, 2021.
Pritchard, A. C. et al. "Osteology, relationships and functional morphology of Weigeltisaurus jaekeli (Diapsida, Weigeltisauridae) based on a complete skeleton from the Upper Permian Kupferschiefer of Germany." PeerJ, 2021.
Xu, X. et al. "A bizarre Jurassic maniraptoran theropod with preserved evidence of membranous wings." Nature, 2015.
Wang, M. et al. "A new Jurassic scansoriopterygid and the loss of membranous wings in theropod dinosaurs." Nature, 2019.
Dececchi, T. A. et al. "Aerodynamics show membrane-winged theropods were a poor gliding dead-end." iScience, 2020.
Godefroit, P. et al. "A Jurassic ornithischian dinosaur from Siberia with both feathers and scales." Science, 2014.
Ji, Q. et al. "A swimming mammaliaform from the Middle Jurassic and ecomorphological diversification of early mammals." Science, 2006.
Meng, J. et al. "A Mesozoic gliding mammal from northeastern China." Nature, 2006.
Luo, Z.-X. & Wible, J. R. "A Late Jurassic digging mammal and early mammalian diversification." Science, 2005.
Hu, Y. et al. "Large Mesozoic mammals fed on young dinosaurs." Nature, 2005.
Luo, Z.-X. et al. "A Jurassic eutherian mammal and divergence of marsupials and placentals." Nature, 2011.