The survival of certain species during mass extinction events has puzzled scientists for centuries. Approximately 66 million years ago, at the end of the Cretaceous period, a catastrophic event wiped out most life on Earth, including the iconic dinosaurs. Shockingly, a sea creature known as the nautiloid managed to survive, while its close relative, the ammonoid, perished. Scientists have debated the reasons for this stark contrast in survival rates.
A recent study conducted by a team of international scientists from Japan, Switzerland, and the United States delved into the metabolic rates of these ancient organisms to shed light on their survival strategies. By analyzing carbon isotopes in shell material, the researchers were able to estimate metabolic rates and draw correlations between metabolism and survivability during mass extinctions.
The study utilized an index called “Kumeta” based on carbon isotope values to compare metabolic rates among modern and ancient shelled organisms. The researchers found that organisms with lower Cmeta values had slower metabolic rates, potentially giving them an edge in surviving harsh environmental conditions.
Comparing Cmeta values between modern and fossil specimens, the researchers identified a significant difference in metabolic rates between nautiluses and other shelled species. Nautiluses exhibited remarkably lower Cmeta values, suggesting a more efficient use of energy and resources, which could explain their survival during mass extinction events.
The study theorized that the nautilus’ low metabolic rate allowed it to thrive in periods of food scarcity, such as the end of the Cretaceous period marked by environmental upheavals. Additionally, factors like egg size, with nautiluses laying larger eggs compared to their extinct counterparts, may have contributed to their survival by ensuring adequate nutrition for offspring.
In concluding their findings, the researchers emphasized the role of low metabolic rates in the nautilus’ survival and highlighted the importance of other factors, like egg size, in enhancing their chances of adaptation and resilience. While the study provided valuable insights, the researchers acknowledged the limitations of fossil-based estimations and the complex interplay of various factors in determining species survival.
Post views: 252
Source: sciworthy.com
