DurhamRedStripe
Midfield
Only as far as technology is concerned. Plenty of species throughout history could be argued to be be more successful than us. It just depends on your criteria for "successful". Ask a cockroach which species on earth is the most successful and they'd probably say cockroaches. Ask a rat and it'd probably say rats. Ask a great white shark and it would probably say great white sharks.
Humans have only been around for a few hundred thousand years. There were dinosaur species that were around for tens of millions of years.
Well if we use the criteria as how much impact we have had on the planet, then considering the short space of time we have been here, we have definitely been the most successful.