Researchers have recorded an orca swimming with a pilot whale calf in a possible interspecies adoption, but how the two came together is a mystery.
The remains of a missing person from Argentina were recently found inside the belly of a dead school shark. But experts say it is improbable that the shark killed him.
The world's first horseback riders swept across the steppe roughly 5,000 years ago, a new skeletal analysis of tombs across Europe and Asia reveals.
A strange blob has been seen rapidly circling our galaxy's central black hole. Now, astronomers have identified it as the exploded debris from two merging stars.