After an asteroid slammed into Earth 66 million years ago, there is very little evidence of fish in the fossil record. Now, a research team including University of Michigan graduate student Sanaa El-Sayed has discovered the earliest known examples of six modern fish groups that still swim in Earth's seas today.

• Fossil fragments suggest Praearcturus gigas represents the largest scorpion ever discovered, perhaps one metre in length

• Specimens held in the Natural History Museum collection since the 1870s have been reinterpreted using modern techniques

• Giant scorpion lived tens of millions of years before other famous “giant” arthropods, reshaping ideas about how and why early arthropods grew so large

Scientists repeatedly sampled microbes from six sites up to 1.5 kilometers deep across four years inside a former goldmine. Microbial ecosystems appear to be structured around shared functions rather than shared species. Each ecosystem was organized around two broad groups of microbes: a stable group and a responsive group. Ecosystems were very different among sites but largely stable through time. Study could have implications for underground engineering projects, including carbon storage.

An international research team led by a researcher at the University of Bern has modeled 1,000 years of earthquake history along the San Andreas and San Jacinto faults in Southern California. The result: stresses in the crust are higher today than at any time in the last millennium – and a critical fault junction near Los Angeles could decide how big the next major earthquake will be.