Ireland's only dinosaurs discovered in Antrim

The only dinosaur bones ever found on the island of Ireland have been formally confirmed for the first time by a team of experts from the University of Portsmouth and Queen's University Belfast, led by Dr. Mike Simms, a curator ...

Brains 'primed' for life on land

A new study adds another layer to the remarkable evolutionary transition of life from water to land on Earth.

Paleontologists discover identical evolution of isolated organisms

Paleontologists at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) and the University of Calgary in Canada have provided new proof of parallel evolution: conodonts, early vertebrates from the Permian period, adapted ...

Palaeontologists describe a preservation process unique to resins

A team of paleontologists described two amber pieces found in sites in Teruel (Spain) with remains from vertebrates corresponding to the Early Cretaceous. Both pieces have their origins in the same conservation process of ...

Global warming triggered the evolution of giant dinosaurs

The word "dinosaur" tends to evoke giant animals with massive bodies, long necks and tails, and tiny heads. These "quintessential dinosaurs" actually represent one prominent subgroup of the Dinosauria, the so called Sauropoda ...

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Fossil

Fossils (from Latin fossus, literally "having been dug up") are the preserved remains or traces of animals, plants, and other organisms from the remote past. The totality of fossils, both discovered and undiscovered, and their placement in fossiliferous (fossil-containing) rock formations and sedimentary layers (strata) is known as the fossil record. The study of fossils across geological time, how they were formed, and the evolutionary relationships between taxa (phylogeny) are some of the most important functions of the science of paleontology. Such a preserved specimen is called a "fossil" if it is older than some minimum age, most often the arbitrary date of 10,000 years ago. Hence, fossils range in age from the youngest at the start of the Holocene Epoch to the oldest from the Archaean Eon several billion years old. The observations that certain fossils were associated with certain rock strata led early geologists to recognize a geological timescale in the 19th century. The development of radiometric dating techniques in the early 20th century allowed geologists to determine the numerical or "absolute" age of the various strata and thereby the included fossils.

Like extant organisms, fossils vary in size from microscopic, such as single bacterial cells only one micrometer in diameter, to gigantic, such as dinosaurs and trees many meters long and weighing many tons. A fossil normally preserves only a portion of the deceased organism, usually that portion that was partially mineralized during life, such as the bones and teeth of vertebrates, or the chitinous exoskeletons of invertebrates. Preservation of soft tissues is rare in the fossil record. Fossils may also consist of the marks left behind by the organism while it was alive, such as the footprint or feces (coprolites) of a reptile. These types of fossil are called trace fossils (or ichnofossils), as opposed to body fossils. Finally, past life leaves some markers that cannot be seen but can be detected in the form of biochemical signals; these are known as chemofossils or biomarkers.

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