Scientists have discovered a treasure trove of ancient squid fossils, shedding new light on the marine ecosystem during the Cretaceous period. A study led by paleobiologist Shin Ikegami at Hokkaido University in Japan and Germany has uncovered 263 fossilized cephalopod beaks, including 40 previously unseen species.
The findings suggest that squids were the most abundant swimmers in the ancient ocean, with body sizes comparable to fish and even larger than ammonites. The researchers used a new technique called grinding tomography to analyze fossils locked away in rock samples. This method allowed them to reconstruct the contents of a 100-million-year-old rock sample, revealing over 1,000 cephalopod beaks.
The smallest squid beaks were just 6% the size of the only previously known fossil squid beak, and their average length was around 3.87 millimeters. These discoveries challenge previous assumptions that squids only thrived on Earth after the mass extinction event that wiped out the dinosaurs 66 million years ago.
According to the researchers, the Cretaceous squid biomass far exceeded that of fish and ammonites, with an explosion of diversity around 100 million years ago. The findings have significant implications for our understanding of marine ecosystems in the past, suggesting that squids were likely the pioneers of fast and intelligent swimmers dominating the modern ocean.
Source: https://www.sciencealert.com/100-million-year-old-rock-reveals-40-never-before-seen-squid-species