The dinosaurgod, or the lord of all the great lizards. A unique specimen, the skeleton of which has never been found, but the image of which appears in many of the earliest cave paintings, depicted as a giant bearded lizard seated on a cloud or floating in a celestial environment.
Early Brontosauri used to raise their heads and low to the sky in praise of the mighty Theosaurus.
Later Brontosauri built piles of rubble in homage to him.
An ancient creature created by one of Tom's less successful time travel experiments. In the near future Tom tries to send himself back in tie to replace Arnie with a young clone of himself, but it goes wrong and the clone goes back 75 million years. A Giganotosaur is the first to discover this lil' clone in the wilderness, but latent temporal warps etc pull them both into another dimension and a genetic fusion merges the two creatures into the Tomosaurus.
At a massive 8000 feet long and with reasonable telekenisis, Tomosaurus is a prime example of how nature + science + insanity = power gaming.
(or to put in Manus-speak, that picture Roxy did for Tom)