This 26 August 2015 video is called Biologist Spots Rare Nautilus For The First Time In 30 Years.
Another video, no longer on YouTube, used to say about itself:
28 August 2015
The Allonautilus scrobiculatus has inhabited the earth for 500 million years and has only been seen twice, until now.
A rare species of nautilus, a marine mollusc, has been found by researchers for the first time in 31 years. It has been suggested that the Allonautilus scrobiculatus could be the rarest animal in the world.
From Wildlife Extra:
Rare nautilus sighted for the first time in 30 years
A rare nautilus has been sighted for the first time in three decades. Allonautilus scrobiculatus is a species of nautilus, marine animals that are small, distant cousins of squid and cuttlefish. They are an ancient lineage of animal, often christened a “living fossil” because their distinctive shells appear in the fossil record over an impressive 500 million year period.
The animal was first discovered by biologist Peter Ward and his colleague Bruce Saunders off of Ndrova Island in Papua New Guinea in 1984, when they realised that their differing gills, jaws, shell shape and male reproductive structures made them different to other nautilus species.
“Some features of the nautilus – like the shell giving it the ‘living fossil’ label — may not have changed for a long time, but other parts have,” said Ward. “It has this thick, hairy, slimy covering on its shell,” said Ward. “When we first saw that, we were astounded.”
This slimy nautilus turned out to be even more elusive than its siblings. Aside from another brief sighting by Saunders in 1986, Allonautilus disappeared until July 2015, when Ward returned to Papua New Guinea to survey nautilus populations.
“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.
“Once they’re gone from an area, they’re gone for good,” said Ward.
Illegal fishing and “mining” operations for nautilus shells have already decimated some populations, Ward said. This unchecked practice could threaten a lineage that has been around longer than the dinosaurs were and survived the two largest mass extinctions in Earth’s history. As it stands now, nautilus mining could cause nautiluses to go extinct.”