nicolaus stenonius was the first person to use fossils for dating rock layers in large-scale practical application.
nicolaus stenonius was the first person to use fossils for dating rock layers in large-scale practical application.
who was the first person to use fossils for dating rock layers in large-scale practical application?
nicolaus stenonius
the regular order of the occurrence of fossils in rock layers was discovered around 1800 by william smith. while digging the somerset coal canal in southwest england, he found that fossils were always in the same order in the rock layers. as he continued his job as a surveyor, he found the same patterns across england. he also found that certain animals were in only certain layers and that they were in the same layers all across england. due to that discovery, smith was able to recognize the order that the rocks were formed. sixteen years after his discovery, he published a geological map of england showing the rocks of different geologic time eras.
relative dating
body fossils and trace fossils are the principal types of evidence about ancient life, and geochemical evidence has helped to decipher the evolution of life before there were organisms large enough to leave body fossils. estimating the dates of these remains is essential but difficult: sometimes adjacent rock layers allow radiometric dating, which provides absolute dates that are accurate to within 0.5%, but more often paleontologists have to rely on relative dating by solving the "jigsaw puzzles" of biostratigraphy (arrangement of rock layers from youngest to oldest). classifying ancient organisms is also difficult, as many do not fit well into the linnaean taxonomy classifying living organisms, and paleontologists more often use cladistics to draw up evolutionary "family trees". the final quarter of the 20th century saw the development of molecular phylogenetics, which investigates how closely organisms are related by measuring the similarity of the dna in their genomes. molecular phylogenetics has also been used to estimate the dates when species diverged, but there is controversy about the reliability of the molecular clock on which such estimates depend.
paleontology