Archaeoindris
Though similar to "Palaeopropithecus", "Archaeoindris" was significantly larger and more robust. "Archaeoindris" was one of the largest primates to ever evolve, and was the largest-known strepsirrhine primate, weighing an estimated . It was roughly the size of an adult male gorilla, which was first noted by Lamberton.
Largest prehistoric animals
There are two contenders for largest-known ever arachnid: "Pulmonoscorpius kirktonensis" and "Brontoscorpio anglicus". Pulmonoscorpius was Brontoscorpio was . The biggest difference is that "Brontoscorpio" was aquatic, and "Pulmonoscorpius" was terrestrial. "Brontoscorpio" is not to be confused with various Eurypterids: it was a true scorpion with a venomous stinger.