Ancient Squid Dominated Oceans Millions of Years Ago, New Fossil Discovery Reveals
Tokyo, Japan – A groundbreaking study published in the journal Science details the discovery of an astonishing 263 squid samples, representing 40 previously unknown species, from limestone deposits in Japan. The findings overturn previous understandings of ancient marine ecosystems, demonstrating that squid were far more prevalent and substantial predators than previously believed.
Researchers, led by Paleobiologist Shin Ikegami of Hokkaido University, analyzed fossilized squid beaks – the only readily fossilized part of the cephalopod body – recovered from limestone formations dating back to the Mesozoic Era (approximately 252 to 66 million years ago). the abundance of these beaks indicates a thriving squid population.
“Both in terms of number and size, this ancient squid clearly dominates the ocean,” Ikegami stated, as reported by Science Alert. “Their body size is equivalent to fish, even bigger than Ammonite that we found with them. This shows that squid developed as the most abundant swimmer in ancient oceans.”
The fossilization process typically favors hard tissues like bone, teeth, and shells. Soft-bodied organisms, like squid, rarely leave behind complete fossil records. Squid bodies are almost entirely composed of soft tissue, with the exception of their beak, made of chitin, and their gladius (pen), a structural support.
The preserved squid beaks are crucial for understanding the evolutionary history of Cephalopoda – the class that includes octopus, nautilus, and cuttlefish – spanning the last 500 million years.Analysis of beak morphology allows scientists to infer species identification, size, and possibly, diet.
The limestone deposits, located in undisclosed locations within Japan to protect the fossil sites, yielded a remarkably diverse collection of squid fossils. The study highlights a previously underestimated role for squid in ancient marine food webs. The sheer number of fossils suggests squid were a major food source for larger marine reptiles and fish.
This discovery challenges the long-held assumption that ammonites were the dominant predators in Mesozoic oceans. The new evidence suggests squid occupied a similar, or even more critically important, ecological niche.
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