I am imagining a project where the development of more advanced brain-computer interfaces allow humans to communicate telepathically with animals, and so discover that numerous species on Earth are sapient. These include African bush, forest and Asian elephants, the common dolphin, Atlantic bottlenose dolphin, spotted dolphin, fin whale, blue whale and humpback whale.
However, I have run into a problem: all these species arose either before or around the same time as humans, so I need a good excuse as to why none have also developed a high-tech civilisation, discovered fire or even developed tools beyond the level of sticks and stones. Any ideas?