Death rays is the first episode of Animal Armageddon. it focuses on the Ordovician extinction.
The Straight-shelled nautiloids are seen hunting Trilobites and Astraspis and competing against Eurypterids. Then a gamma ray burst hits the earth. The ocean animals try to survive it. Astraspis is doing better then most animals since there food doesn't go away for now. Then with ice sheets heading there way, Straight shelled nautiloids head down to the deep ocean, only to be killed by the pressure. Coiled nautiloids are doing better, but have a tough time having young. Eurypterids are doing good as well, even causing them to hunt Straight shelled nautiloids. Once extinction ends, Straight shelled nautiloids are smaller then normal, trilobites and coiled nautiloids are doing better, eurypterids can go on to land, Astraspis evolves into many fish including Acanthodians and with this a new predator Pterygotus prowls the seas.
- Straight-shelled nautiloids
- Coiled nautiloids
- Pterygotus(extended version only)
Opabinia was going to appear in this episode, but was cut due to timing.
As of 2017, it has been shown that it was actually a large volcanic eruption that caused the Ordovician extinction.