This ancient Philippine sea creature has survived for millions of years—but for how much longer?

Timothy James Dimacali

Posted at Oct 08 2020 02:36 AM | Updated as of Oct 08 2020 12:51 PM

Nautilus fossils have been found in Calatagan, Batangas, dating back some 4 million years. The specimens bear a close resemblance to the modern-day Nautilus pompilius, which still lives in Philippine waters but is almost endangered due to overfishing for its beautiful shell.

The Nautilus or “lagan” as it’s called in the Philippines is prized for its beautifully curved pearlescent shell, and is considered a “living fossil” because it has remained almost unchanged for millions of years. Yet despite having survived for longer than modern humans have walked the Earth, the Nautilus’ days may be numbered because of humans themselves. 

The oldest known examples in the country were recently discovered and described in the September 2020 issue of the Philippine Journal of Science and dated to between the late Miocene and early Pliocene epoch—making them at least 3.6 million years old.

While the researchers could not confirm the exact species of Nautilus that they had discovered due to the fossils’ poor state of preservation, they did note a very close similarity to the still-living Nautilus pompilius. Commonly known as the “Chambered Nautilus” or “Pearly Nautilus,” N. pompilius can be found in the Philippines and is often cited in textbooks as an example of mathematical perfection in nature. 

Scientists from the University of the Philippines, the National Museum of the Philippines, and Ramon Magsaysay State University found the fossils in sedimentary deposits in Talim Point in Lian, Batangas. 

Ancient Philippine biodiversity

“This discovery, along with other fossil work in the area, shows us that this area of Batangas was quite diverse at the time that this Nautilus was living, with a coral reef teeming with marine organisms familiar to us today,” said Dr. Alyssa M. Peleo-Alampay, one of the paper’s authors, in an email interview.

Today, the aptly named Talim Point is a dagger-shaped peninsula with a wide stretch of sandy beach that looks out to the West Philippine Sea. But back when these Nautilus fossils were still alive, much of what we know as the Philippines was underwater. The abundance of sedimentary rock in the country today attests to this submarine past.

“Limestones, which are ancient coral reefs, are common throughout the Philippines. They indicate deposition in a marine environment and are also indicators of a warm, tropical climate,” said co-author Dr. Allan Gil S. Fernando.

Apart from the Nautilus fossils, the researchers also found fossilized plankton, sea urchins, and shellfish, as well as coral fragments. These led them to believe that the area was once a shallow marine environment near a coral reef. “The fossils that we found are a combination of shallow and deep-water species, and a few of them are fragmented. We believe these fossils were not originally in the area we found them in but were instead transported by waves from somewhere nearby,” they said.

Nautilus overfishing
 
Sadly, however, the Nautilus’ remarkable beauty has been their undoing. A study by Traffic.org pointed to the Philippines as one of the world’s main sources of Nautilus products despite a ban on Nautilus fishing in some parts of the country. The industry seems to be completely driven by overseas demand: Nautilus is not considered a delicacy anywhere in the Philippines, due to its tough and difficult to preserve meat, nor does the creature figure in any local cultural traditions. As a result, their population in the Philippines has declined by as much as 80 percent due to overfishing.

“There is a significant lack of management and control on the fishing of nautilus in the Philippines,” Traffic.org noted in its report. “Absent adequate information on the population status of stocks, and specifics of the life history traits of nautilus, including slow growth and low reproductive rates, makes the species very susceptible to overharvest.” 

This lack of information is ironic, given how the fossils discovered in Batangas have put the Philippines in the spotlight of the global scientific community: the finds are not just the oldest fossil Nautilus in the Philippines, they are also the only known examples in the world to date from the late Miocene to early Pliocene epoch, between 3.6 million and 11.6 million years ago. 

“This particular research reveals the importance of the Philippines in providing information about the evolution and taxonomy of the genus Nautilus,” explained Abigael Castro, the paper’s corresponding author. “There is a gap in the fossil record, and the Batangas Nautilus fills this gap.” 

That we have come so far in understanding this ancient and enigmatic creature, only for it to slip away into oblivion by our own hands would be a tragedy beyond measure.