There doesn't seem to be an end in finding prehistoric species. We know, logically, that a limited numbers of species have lived on Earth, but we clearly haven't found them all yet, and they just keep coming.
The last few years have given us the biggest bear (we think) that ever lived, Arctotherium angustiden, the biggest snake (the 12-13m Titanoboa), , and the biggest crocodile, Crocodylus thorbjarnarsoni, along with the ancestor of today's sperm whale, who by the way was even more formidable than the modern type.
Then in just the last week we added two discoveries. Scientists exploring the Peruvian area of the Amazon basin found seven species of crocodiles, including three new species, dating back 13 million years (2.5 million years older then the Amazon itself). There have never been as many species of croc living in the same habitat at the same time. This find dwarfs modern diversity (we don't have more than three crocs in the same area today) and introduced three new animals, including a weird-looking clam hunter with rounded teeth and the snout of a shovel. As paleontologist Rodolfo Salas-Gismondi put it, "We uncovered this special moment in time when the ancient mega-wetland ecosystem reached its peak in size and complexity, just before its demise and the start of the modern Amazon River system." Wow. Cool.
In the second item passed onto me by my friend Kris Winkler this week, paleontologists are exploring, with exquisite care, a specimen never seen before: a frozen baby woolly rhinoceros. Hunters who found "Sasha" took her for a recent reindeer carcass until they saw the horn. She is estimated at 10,000 years old, and scientists hope she yields high-quality DNA (not to make new rhinos - that is still beyond us - but to sequence the animal's genome and learn far more about it than we know today). The animal was a contemporary of the famous mammoth, but there's some debate over its appearance. Not anymore.
Exploration goes in every direction - across time, across space, across the frontiers of the mind. We are privileged to live in a time with more tools for exploration than any society before us. We shouldn't waste the opportunity.
The giant snake Titanoboa swallowing a crocodile
(NASM exhibit photographed by author)