From New Scientist:
Living fossil nautilus re-emerges after 30 years of hiding
Ward, who is a biologist at the University of Washington in Seattle, and his colleague Bruce Saunders first described A. scrobiculatus in 1984. Its shell shape looks unwieldy compared with the more streamlined shells of other animals in the Nautilidae family, but it appears to have evolved that way relatively recently. “It turned on its head what we thought of as primitive,” says Ward.
Stop using the term “primitive.” What does it mean anyway?
See also: Species assumed to be extinct sometimes turn up again. In part, this is probably due in part to the relatively shorter time today before extinction fears arise. For example,
“They swim just above the bottom of wherever they are,” said Ward. “Just like submarines, they have ‘fail depths’ where they’ll die if they go too deep, and surface waters are so warm that they usually can’t go up there. Water about 2,600 feet deep is going to isolate them.”
These restrictions on where nautiluses can go mean that populations near one island or coral reef can differ genetically or ecologically from those at another. The findings also pose a challenge for conservationists.
Who knew this centuries ago?