Acid dissolution is a technique of removing a fossil from the surrounding rock matrix in which it is encased by dissolving that matrix with acid. Fossilized bone, though strong enough to be preserved for thousands or millions of years, is often more delicate than rock. Once a fossil is discovered, scientists must remove the fossil from its surroundings without damaging the fossil itself. Scient...

Divergence dating studies, which combine temporal data from the fossil record with branch length data from molecular phylogenetic trees, represent a rapidly expanding approach to understanding the history of life. National Evolutionary Synthesis Center hosted the first Fossil Calibrations Working Group (3-6 March, 2011, Durham, NC, USA), bringing together palaeontologists, molecular evolutionis...

A new fossil species of salticid spider (Araneae: Salticidae) is described based on an amber-embedded specimen. The specimen was collected from lignite-sandstone early-mid Miocene sediments near the town of Totolapa in Chiapas, southwestern Mexico. The diagnosis and description is supported by key characters that best match the genus Maevia Koch, 1846. Thus, this new fossil species has been nam...

We have examined the Fourier power spectrum of extinction, origination, and total biodiversity in the marine fossil record. We find them inconsistent with self-similarity as well as random walk behavior, but instead dominated by low-frequency power. Even in the background of this low-frequency dominance, the 62 My biodiversity cycle is predominant. A recent analysis 1 of fossil biodiversity fou...

From their earliest origins, fishes have developed a suite of adaptations for locomotion in water, which determine performance and ultimately fitness. Even without data from behaviour, soft tissue and extant relatives, it is possible to infer a wealth of palaeobiological and palaeoecological information. As in extant species, aspects of gross morphology such as streamlining, fin position and ta...

The dynamic nature of the master calcium signaling protein, calmodulin, schematically illustrated by snapshots from an interpolation between its calcium-bound state (blue) and its structure bound to both calcium and a peptide derived from one of its downstream cellular targets, myosin light chain kinase (red), generated using the Yale Morph Server and PyMol software. See the special section beg...