Search results
Results from the WOW.Com Content Network
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.
Paleobotany, also spelled as palaeobotany, is the branch of botany dealing with the recovery and identification of plant remains from geological contexts, and their use for the biological reconstruction of past environments (paleogeography), and the evolutionary history of plants, with a bearing upon the evolution of life in general.
Equisetum (/ ˌ ɛ k w ɪ ˈ s iː t əm /; horsetail) is the only living genus in Equisetaceae, a family of vascular plants that reproduce by spores rather than seeds. [2]Equisetum is a "living fossil", the only living genus of the entire subclass Equisetidae, which for over 100 million years was much more diverse and dominated the understorey of late Paleozoic forests.
The age of individual plants is difficult to assess, but many plants may be over 1,000 years old. Some individuals may be more than 2,000 years old. [12] As the species does not produce yearly rings, plant age is determined by radiocarbon dating. [19] However, other reports suggest that the plant does produce a kind of yearly ring. [8]
The coelacanth was long considered a "living fossil" because scientists thought it was the sole remaining member of a taxon otherwise known only from fossils, with no close relatives alive, [8] and that it evolved into roughly its current form approximately 400 million years ago. [1]
Graptolite fossils have predictable preservation, widespread distribution, and gradual change over a geologic time scale. This allows them to be used to date strata of rocks throughout the world. [8] They are important index fossils for dating Palaeozoic rocks as they evolved rapidly with time and formed many different distinctive species.
This list of fossils with consumulites contains fossil specimens discovered to contain the preserved remains of food that the deceased animal had ingested during life. Such consumulites are a type of bromalite, the broader term applied to fossilized material ingested by an animal including waste expelled from the body like feces and vomit (regurgitalites).
For fossil species, exact or even approximate numbers are harder to find; Raup, 1986 [15] includes data based on a compilation of 250,000 fossil species so the true number is undoubtedly somewhat higher than this. The number of described species is increasing by around 18,000–19,000 extant, and approaching 2,000 fossil species each year, as ...