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A living fossil is a deprecated term for an extant taxon that phenotypically resembles related species known only from the fossil record. To be considered a living fossil, the fossil species must be old relative to the time of origin of the extant clade. Living fossils commonly are of species-poor lineages, but they need not be.
' obtained by digging ') [1] is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the fossil record. Though the ...
Non-cellular life, also known as acellular life, is life that exists without a cellular structure for at least part of its life cycle. [1] Historically, most definitions of life postulated that an organism must be composed of one or more cells, [2] but, for some, this is no longer considered necessary, and modern criteria allow for forms of life based on other structural arrangements.
Predating dinosaurs, the horseshoe crab has roamed the earth for 445 million years, surviving five mass extinctions and three ice ages, but overfishing and habitat loss pose the greatest challenge ...
The history of paleontology traces the history of the effort to understand the history of life on Earth by studying the fossil record left behind by living organisms. Since it is concerned with understanding living organisms of the past, paleontology can be considered to be a field of biology, but its historical development has been closely tied to geology and the effort to understand the ...
Fossils of organisms' bodies are usually the most informative type of evidence. The most common types are wood, bones, and shells. [59] Fossilisation is a rare event, and most fossils are destroyed by erosion or metamorphism before they can be observed. Hence the fossil record is very incomplete, increasingly so further back in time.
T here’s certainly nothing living on the asteroid Bennu, an airless, 1,614-ft. rubble pile orbiting the sun about 40.2 million miles from Earth. But that doesn’t mean that Bennu hasn’t all ...
Palaeozoology, also spelled as Paleozoology (Greek: παλαιόν, palaeon "old" and ζῷον, zoon "animal"), is the branch of paleontology, paleobiology, or zoology dealing with the recovery and identification of multicellular animal remains from geological (or even archeological) contexts, and the use of these fossils in the reconstruction of prehistoric environments and ancient ecosystems.