Editing Microfossil (section)

==Conodonts==
[[File:Conodonts from the Glen Dean formation (Chester) of the Illinois basin (1958) (20654535006).jpg|thumb| {{center|Conodont element found from the [[Cambrian]] to the end of the [[Triassic]]}}]]
{{see also|Conodont biostratigraphy}}

Conodonts (''cone tooth'' in Greek) are tiny, extinct jawless fish that resemble eels. For many years, they were known only from tooth-like microfossils found in isolation and now called conodont elements. The evolution of [[mineralized tissues]] has been a puzzle for more than a century. It has been hypothesized that the first mechanism of chordate tissue mineralization began either in the oral skeleton of conodont or the dermal skeleton of early [[agnathans]].<ref name=Shubin2009 /> Conodont elements are made of a phosphatic mineral, [[hydroxylapatite]].<ref>{{cite journal | doi = 10.1016/j.chemgeo.2006.03.004 | volume=233 | title=Chemical systematics of conodont apatite determined by laser ablation ICPMS | year=2006 | journal=Chemical Geology | pages=196–216 | last1 = Trotter | first1 = Julie A.| issue=3–4 | bibcode=2006ChGeo.233..196T }}</ref>

The element array constituted a feeding apparatus that is radically different from the jaws of modern animals. They are now termed "conodont elements" to avoid confusion. The three forms of teeth (i.e., coniform cones, ramiform bars, and pectiniform platforms) probably performed different functions. For many years, conodonts were known only from enigmatic tooth-like microfossils (200 micrometres to 5 millimetres in length) which occur commonly, but not always in isolation, and were not associated with any other fossil.<ref>{{cite web|last1=MIRACLE|title=Conodonts|url=http://www.ucl.ac.uk/GeolSci/micropal/conodont.html|access-date=26 August 2014}}</ref>

[[Conodonts]] are globally widespread in sediments.Their many forms are considered [[index fossil]]s, fossils used to define and identify geological periods and date strata. Conodonts elements can be used to estimate the temperatures rocks have been exposed to, which allows the thermal maturation levels of sedimentary rocks to be determined, which is important for [[hydrocarbon exploration]].<ref>[https://phys.org/news/2019-08-microfossils-extreme-global-environmental.html Study of microfossils maps extreme global warming and environmental change] ''Phys.org'', 7 August 2019.</ref><ref>{{cite journal |title = Recurrent biotic rebounds during the Early Triassic: Biostratigraphy and temporal size variation of conodonts from the Nanpanjiang Basin, South China|year = 2019|doi = 10.1144/jgs2019-065|last1 = Wu|first1 = Kui|last2 = Tian|first2 = Li|last3 = Liang|first3 = Lei|last4 = Metcalfe|first4 = Ian|last5 = Chu|first5 = Daoliang|last6 = Tong|first6 = Jinnan|journal = Journal of the Geological Society|volume = 176|issue = 6|pages = 1232–1246|bibcode = 2019JGSoc.176.1232W|s2cid = 202181855}}</ref>  Conodont [[tooth|teeth]] are the earliest vertebrate teeth found in the fossil record,<ref name=Shubin2009>{{cite book|last=Shubin|first=Neil|title=Your Inner Fish: A Journey into the 3.5 Billion Year History of the Human Body|year=2009|edition=reprint|publisher=Pantheon Books|location=New York|isbn=9780307277459|pages=85–86}}</ref> and some conodont teeth are the sharpest that have ever been recorded.<ref>[http://www.sci-news.com/paleontology/article00217.html Scientists Discover Sharpest Teeth in History] ''Sci-News.com'', 20 March 2012.</ref><ref>{{cite journal |title = The sharpest tools in the box? Quantitative analysis of conodont element functional morphology|year = 2012|doi = 10.1098/rspb.2012.0147|last1 = Jones|first1 = David|last2 = Evans|first2 = Alistair R.|last3 = Siu|first3 = Karen K. W.|last4 = Rayfield|first4 = Emily J.|last5 = Donoghue|first5 = Philip C. J.|journal = Proceedings of the Royal Society B: Biological Sciences|volume = 279|issue = 1739|pages = 2849–2854|pmid = 22418253|pmc = 3367778}}</ref>

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