Hot on the flippers of the Australian snubfin dolphin (Orcaella heinsohni) discovery comes the second new Australian dolphin in a decade: the newest member of a group called the humpback dolphins. The species, still not named, is the fourth known in the genus Sousa and lives off northern Australia. (Humpback dolphins have a hump below the dorsal fin which is sometimes prominent enough to make the animal look like it's toting a small aqualung.) The new species doesn't look much different from its genus-mates, but study of 180 skulls and 235 tissue samples were involved in determining its distinctness. We don't know about its population or conservation status. Dolphins in general are having a hard time of it even after the mass slaughter involved in tuna fishing has been drastically reduced. The baji (Lipotes vexillifer) is likely extinct, and four other species are in extreme danger. Here's a good overview of the 5 most endangered cetaceans.