Octopuses would be my first guess, but their reproduction cycle would have to vastly change to allow for the passing down of knowledge

  • 1
    $\begingroup$ intelligence is not always an evolutionary benefit. Some animals did dumb down over evolucion and thus reduced food and oxygen needs by a complex brain. Armadillos are one of these - their upside? They can hold breath far longer than their body would make you assume! $\endgroup$ – Trish Jan 26 at 0:00
  • 2
    $\begingroup$ Hi and welcome! Your question, while interesting, is in the close queue. It is by nature opinion based, but also, there's really no worldbuilding context here. A simple "what if" query doesn't cut it: in order for your question to be on topic here you need to offer some detail as to the kind of fictional world you're making and what happened to all the vertebrates. $\endgroup$ – elemtilas Jan 26 at 1:08

There is no guarantee that any would. The “obvious” candidate would be one of the cephalopods, but I suspect that to become truly sapient as we understand the word would require a major change in their environment and a lot of evolutionary pressure over a great deal of time. We can’t really tell what those might be or what might result in any sort of detail.

|improve this answer|||||

Not the answer you're looking for? Browse other questions tagged or ask your own question.