Dinosaur study challenges Bergmann's rule
When you throw dinosaurs into the mix, sometimes you find that a rule simply isn't.
When you throw dinosaurs into the mix, sometimes you find that a rule simply isn't.
Paleontology & Fossils
Apr 6, 2024
4
361
An unusual reduction in the strength of Earth's magnetic field between 591 and 565 million years ago coincided with a significant increase in the oxygen levels in the atmosphere and oceans, according to a paper published ...
Earth Sciences
May 2, 2024
1
678
Biomineralized columns, stacked in layers like a sandwich gave Cambrian brachiopod shells their strength and flexibility 520 million years ago.
Evolution
Apr 18, 2024
0
33
Water lettuce (Pistia stratiotes L.), also known as Nile cabbage, is a free-floating aquatic plant from the family Araceae, the same family as the arum lily.
Plants & Animals
Apr 10, 2024
0
1
Current concentrations of carbon dioxide (CO₂) in Earth's atmosphere are unprecedented in human history. But CO₂ levels today, and those that might occur in coming decades, did occur millions of years ago.
Earth Sciences
May 1, 2024
0
4
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.
This text uses material from Wikipedia, licensed under CC BY-SA