A very unusual-looking underwater creature that lived 68 million years ago resembled a paperclip. And if that isn’t odd enough, the creature lived an exceptionally long life of around 200 years. It measured nearly 5 feet in length and had a shell.
The squid-like creature that’s called Diplomoceras maximum was an ammonite which was once a group of tentacle cephalopods. Ammonites thrived in the waters between 240 and 65 million years ago although they first appeared around 415 million years ago as small, straight shelled creatures called Bacrites. Ammonites went through two major events where they faced extinction – the first time was around 250 million years ago when only 10% of them survived; and the second time was about 206 million years ago when they again faced extinction but ended up surviving. The third time, however, they weren’t so lucky and that was at the end of the Cretaceous period when they became extinct. Interestingly, that was also around the same time that dinosaurs became extinct.
The new research on the Diplomoceras maximum species was presented during an online meeting of the Geological Society of America where Professor Linda Ivany and scientist Emily Artruc from Syracuse University in New York revealed their findings. They explained how chemical signatures found on a 50-centimeter-long (almost 20 inches) portion of the creature’s shell showed how much methane was released each year from the bottom of the ocean. Additionally, each year that the creature was alive was revealed by the sculptural ridges and that a new rib was added to the shell every year that it lived, therefore, indicating that it was alive as long as 200 years.
Interestingly, today’s cephalopods (like squid and octopuses) only live around five years while shelled cephalopods (such as the nautilus) can live into their 20s – but still nowhere near the 200-year lifespan of the Diplomoceras maximum.
So how did the Diplomoceras maximum end up living such a long life? Scientists believe that the species had a slow metabolism that may have been brought on by living close to Antarctica which meant that the food was probably scarce especially during the dark, long winter months. Another interesting fact is that since they lived such long lives, they would have had more opportunities to reproduce.
Since they became extinct around the same time as the dinosaurs, learning about this creature is even more important and interesting. “If you know something about an organism's life span, you learn a lot about its ecology,” Ivany said.
An artist’s impression of Diplomoceras maximum can be seen here.