The June issue of National Geographic has an article and some great photos of these ruddy, pink-skinned creatures, which I only caught a glimpse of in the Bolivian Amazon near Rurrenabaque. They would pop up around our boat but never gave us a good look.
Interestingly, these guys are not cousins of the standard Flipper-style ocean dolphins. In fact they evolved completely independently even before the ocean dwellers were around. Fascinating stuff:
River dolphins evolved from archaic marine cetaceans (the order that also includes whales) on at least three separate occasions—first in India, later in China and in South America—before modern marine dolphins themselves had emerged as a distinct group. In an example of what's known as convergent evolution, geographically isolated and genetically distinct species developed similar characteristics because they were adjusting to similar environments.
