1999 Walking with... 02 Reptile's Beginnings

The Mesothelae spider in the program was based on Megarachne, which during the show&production was thought to be the largest spider ever to live. However, as production was wrapping up, another specimen of Megarachne was discovered that led to the realization that it was actually a eurypterid, leading to the animal in the program being referred to as a speculative species of giant mesothelae spider (an actual group of extant spiders that existed back in the Carboniferous, but its members only vaguely resembled the one from the program and were nowhere near as large). Proterogyrinus was not an amphibian, though it may have lived an amphibious lifestyle. It was possibly a reptiliomorph. There is no evidence suggesting that Arthropleura had powerful jaws, given the fact that its mouthparts have never been preserved along with the rest of the animal. Arthropleura is now known to be a true millipede rather than a distant relative of them. Arthropleura&ability to rear up is purely speculative, and it might not have been possible in real life. Petrolacosaurus is incorrectly shown evolving into the synapsid Edaphosaurus, when in fact, it was an early diapsid, and could therefore not have been the ancestor of any synapsids. The most basal synapsid, Protoclepsydrops, would have been a more suitable candidate. However Edaphosaurus were already present 300 million years ago, so their ancestors would still be Edaphosaurus. The Dimetrodon hatchlings are shown with their back sails fully...