Dolphins are aquatic, cetacean mammals from old Earth; members of the Delphinoidean group of toothed whales, which includes porpoises but excludes some other species of commonly called river dolphins. There were over forty baseline species on Old Earth prior to the Great Dying, ranging in adult size from 1.5 metres (Commerson's Dolphin) to 9.5 metres (the Orca or Killer Whale).
Classed as fish-eating toothed whales, these creatures are among the most intelligent of presapients, and have a primitive language-like set of vocal communications which varies in complexity from species to species.
After chimpanzees and other nonhuman apes, dolphins were the next logical step in provolution experiments. They proved to be a major challenge due to their extremely different ways of thinking, but historians of bioengineering agree that the eventual success was the sign that provolution science had left its infancy. Success with Dolphin species led eventually to provolution of numerous other cetacean species.
Baseline, unmodified dolphins have been introduced into earth-like environments throughout the Terragen Sphere, and the genetic code for most species is widely available for download. All of the species extant in the Information Age are believed to have been lazurogened by GAIA on Old Earth, and there are many very authentic-seeming lazurogens elsewhere. A much larger number of derived species are also recorded.