Amplified seasonality in western Europe in a warmer world.

Documenting the seasonal temperature cycle constitutes an essential step toward mitigating risks associated with extreme weather events in a future warmer world. The mid-Piacenzian Warm Period (mPWP), 3.3 to 3.

High-precision stable isotope analysis of <5 μg CaCO samples by continuous-flow mass spectrometry.

Rationale: Oxygen (δ O) and carbon (δ C) isotope analysis of foraminifera and other CaCO samples has been a key technique for paleoceanographical and paleoclimatological research for more than 60 years. There is ongoing demand for the analysis of ever smaller CaCO samples, driven, for example, by the desire to analyse single specimen planktic foraminifera, or small samples of tooth enamel.

Methods: We present a continuous-flow mass spectrometric technique that uses cryo-focusing of sample CO to analyse CaCO samples in a weight range between 10 and 3 μg.

Hierarchical random walks in trace fossils and the origin of optimal search behavior.

Efficient searching is crucial for timely location of food and other resources. Recent studies show that diverse living animals use a theoretically optimal scale-free random search for sparse resources known as a Lévy walk, but little is known of the origins and evolution of foraging behavior and the search strategies of extinct organisms. Here, using simulations of self-avoiding trace fossil trails, we show that randomly introduced strophotaxis (U-turns)--initiated by obstructions such as self-trail avoidance or innate cueing--leads to random looping patterns with clustering across increasing scales that is consistent with the presence of Lévy walks.