The top ocean predators during the Cretaceous were primarily giant marine reptiles and sharks, or so researchers have thought. Now, a new study suggests colossal “kraken-like” octopuses once hunted Late Cretaceous seas, growing as large as 19 meters in length and competing with – and perhaps even preying upon – large ocean apex predators like mosasaurs. For hundreds of millions of years, marine ecosystems were thought to be dominated by large vertebrate apex predators. Invertebrates served as smaller prey. However, unlike shelled invertebrates, octopuses followed a unique evolutionary trajectory. Instead of protective shells, these creatures evolved soft-bodies, which gave them unprecedented mobility, vision, and intelligence. Some of these species grew to enormous sizes, too, and have functioned as top-tier predators, yet their precise ecological role has remained uncertain due to limited fossil evidence.

To aim to fill this gap, Shin Ikegami and colleagues evaluated the patterns of wear on fossilized jaws of ancient octopus relatives. Wear on the jaw – produced when biting into hard, skeletal prey – leaves characteristic damage similar to the damage seen in modern shell-crushing cephalopods. Measurements of an octopus jaw can also be used to estimate their overall body size. Ikegami et al. reexamined 15 large fossil jaws from ancient octopus relatives and identified clear signs of wear on particularly well-preserved specimens. Using advanced digital fossil-mining techniques, they uncovered 12 additional jaws of finned octopuses from Late Cretaceous sediments (~100 to 72 million years ago). In analyzing them, they identified two main species – Nanaimoteuthis jeletzkyi and N. haggarti. These finned octopuses, N. haggarti in particular, grew to exceptional sizes, say the authors, ranging from ~7 to 19 meters, rivaling the size of contemporaneous giant marine reptiles and potentially representing the largest invertebrates currently described. Moreover, in the largest individuals, the jaws showed extensive wear, with once-sharp features in small juveniles becoming blunted and rounded over time. The wear patterns suggest that these creatures were active carnivores that routinely crushed hard shells and bones with powerful bites, and used their long, flexible arms to seize sizable prey while dismantling it with their strong beaks, a behavior that has been linked to advanced intelligence. According to Ikegami et al., the findings indicate that N. jeletzkyi and N. haggarti were not merely prey but highly active participants in shaping marine ecosystems while occupying roles previously attributed only to large vertebrates.

New high-altitude measurements have revealed a hidden population of extremely small, organic-rich aerosol particles in the lower stratosphere. The findings suggest that these ultrafine aerosols, likely lofted from the underlying troposhpere, are far more abundant and chemically influential than previously understood. The stratospheric aerosol layer, extending from roughly 8 to 35 kilometers above Earth’s surface, plays a crucial role in regulating climate by reflecting sunlight and enabling chemical reactions that influence atmospheric composition. Yet, despite its importance, our understanding of its constituent particles remains incomplete, largely because existing instruments struggle to detect the smallest particles, which fall below their sensitivity thresholds. It’s thought that extremely small particles from the lower atmosphere are transported into the stratosphere through processes such as tropical uplift, atmospheric mixing, intense storm systems, wildfire-driven convection, and even aircraft emissions. However, detailed information about their size distribution, which is critical for determining their volume, surface area, and role in chemical processes, has remained scarce.

Using data collected by a high-altitude research aircraft during the NASA Stratospheric Aerosol Processes, Budget, and Radiative Effects (SABRE) project in 2023, Ming Lyu and colleagues report detailed measurements of stratospheric particles ranging from 0.003 to 2.4 microns, capturing both their distribution and chemical compositions in regions up to 19 kilometers above Earth. In their analysis, Lyu et al. reveal notably high concentrations of extremely small, organic-rich aerosol particles, particularly in atmospheric regions influenced by recently transported air and within the polar vortex. Despite being exceptionally small, these particles dominate the surface area available for heterogeneous atmospheric chemistry and act as a significant condensation sink. Lyu et al. confirmed that many of these fine organic-rich particles originate from the lower atmosphere and subsequently interact with larger sulfur-based aerosols, including those formed from volcanic emissions. This interaction produces a complex, bimodal particle size distribution that current climate models fail to accurately reproduce.

Just as major global powers are retreating from climate finance commitments, a new empirical study provides, for the first time, evidence of a direct link between climate finance and a lower risk of resource-related conflict in developing countries.