The mosasaur fossil record through the lens of fossil completeness

Fossil embryos deep in the fossil record

Embryos have been found in ‘old’ rocks on four continents, especially in Siberia, Nevada, Australia and China. They have been discovered in sedimentary rocks of even Late Neoproterozoic age, assuming the evolutionary geological column1 (figure 1). The Neoproterozoic is the period, so called, between 1 billion and 550 million years ago. This discovery was in the Doushantuo Formation, Guizhou Pro...

Completeness metrics and the quality of the sauropodomorph fossil record through geological and historical time

—Despite increasing concerns about the effect of sampling biases on our reading of the fossil record, few studies have considered the completeness of the fossil remains themselves, and those that have tend to apply non-quantitative measures of preservation quality. Here we outline two new types of metric for quantifying the completeness of the fossil remains of taxa through time, using sauropod...

The Primate Fossil Record

The Fossil Record of Cyanobacteria

2.4 Cyanobacterial Fossils.................................................. 22 2.4.1 Filamentous Cyanobacteria ............................................ 22 2.4.1.1 Oscillatoriaceae .............................................................. 22 2.4.1.2 Nostocaceae .................................................................... 24 2.4.2 Coccoid and Ellipsoid Cyanobacteria ...............

Asymmetry in the fossil record

Asymmetry is a fundamental aspect of the biology of all organisms, and has a deep evolutionary history. The fossil record contains evidence of both morphological and behavioural asymmetries. Morphological asymmetry is most commonly expressed as conspicuous, directional asymmetry (either lateral asymmetry or spiral asymmetry) in body fossils. Few examples of fluctuating asymmetry, a form of subt...