I don't think Rooter is mentioned on the official page. However, the official sources are not exactly incontestable if it comes to naming any characters species. Some official sources even contradict each other. Ducky for example was said to be an Anatosaurus in a file that was issued to the press back in 1988 (she can't be, as that species didn't have any crest), while the official page claims her to be a Parasaurolophus (very unlikely if we compare her and her parents to the Parasaurolophus shown during the LBT 4 song "Grandma's lullaby), and other sources have named her a Saurolophus (the species which I suppose comes closest to the outward appearance of Ducky).
I have seen Littlefoot named a "Brontosaurus" (a name that was mistakenly given to a species that had already been discovered and dubbed Apatosaurus) or a Brachiosaurus in official sources.
Petrie too appears as a Pteranodon in one and a Pterodactylus in the other source.
Somewhat overenthusiastic fans too cast their opinions in claiming them to be facts. Littlefoot for example was claimed to be an Alamosaurus by some fans in order to find a sauropod that lived in the Cretaceous same as Ducky and Cera would have.
The use of science in LBT matters is questionable. It can be fun to try to apply science to LBT, but if one takes such attempts serious one is bound to run frustrated.