Editing Acritarch (section)

==Classification==

The informal group, Acritarcha Evitt 1963, was originally divided into the Subgroups: Acanthomorphitae, Polygonomorphitae, Prismatomorphitae, Oömorphitae, Netromorphitae, Dinetromorphitae, Stephanomorphitae, Pteromorphitae, Herkomorphitae, Platymorphitae, Sphaeromorphitae, and Disphaeromorphitae.<ref>{{cite journal |last1=Strother |first1=Paul |title=Palynomorph focus: Acritarchs. |journal=AASP – The Palynological Society Newsletter |volume=56 |issue=3 |pages=29–33}}</ref><ref>{{cite web |last1=Strother |first1=Paul |title=Acritarchs |url=https://palynology.org/what-is-palynology/palynomorphs/acritarchs/ |website=The Palynological Society |publisher=AASP-The Palynological Society |access-date=12 July 2024}}</ref><ref>{{Cite journal|last=Evitt|first=William R.|date=1963|title=A discussion and proposals concerning fossil dinoflagellates, hystrichospheres, and acritarchs, II|url=http://www.pnas.org/content/pnas/49/3/298.full.pdf|journal=Proceedings of the National Academy of Sciences|volume=49|issue=3|pages=298–302|via=PNAS|doi=10.1073/pnas.49.3.298|pmid=16591055|pmc=299818|bibcode=1963PNAS...49..298E|doi-access=free}}</ref>

Acritarchs were most likely [[eukaryote]]s. While archaea and bacteria ([[prokaryotes]]) usually produce simple fossils of a very small size, eukaryotic unicellular fossils are usually larger and more complex, with external morphological projections and ornamentation such as spines and hairs that only eukaryotes can produce; as most acritarchs have external projections (e.g., hair, spines, thick cell membranes, etc.), they are predominantly eukaryotes, although simple eukaryote acritarchs also exist.<ref>{{Cite journal| doi = 10.1038/463885a| pmid = 20164911| year = 2010| last1 = Buick | first1 = R. .| title = Early life: Ancient acritarchs| volume = 463| issue = 7283| pages = 885–886| journal = Nature |bibcode = 2010Natur.463..885B | doi-access = free}}</ref>

The recent application of [[atomic force microscopy]], [[confocal microscopy]], [[Raman spectroscopy]], and other sophisticated analytic techniques to the study of the ultrastructure, life history, and systematic affinities of mineralized, but originally organic-walled microfossils,<ref>{{cite journal |doi = 10.1073/pnas.142310299|title = Atomic force microscopy of Precambrian microscopic fossils|year = 2002|last1 = Kempe|first1 = A.|last2 = Schopf|first2 = J. W.|last3 = Altermann|first3 = W.|last4 = Kudryavtsev|first4 = A. B.|last5 = Heckl|first5 = W. M.|journal = Proceedings of the National Academy of Sciences|volume = 99|issue = 14|pages = 9117–9120|pmid = 12089337|pmc = 123103|bibcode = 2002PNAS...99.9117K|doi-access = free}}</ref><ref>{{cite journal |doi = 10.1016/j.precamres.2005.07.002|title = Focussed ion beam preparation and in situ nanoscopic study of Precambrian acritarchs|year = 2005|last1 = Kempe|first1 = A.|last2 = Wirth|first2 = R.|last3 = Altermann|first3 = W.|last4 = Stark|first4 = R.|last5 = Schopf|first5 = J.|last6 = Heckl|first6 = W.|journal = Precambrian Research|volume = 140|issue = 1–2|pages = 36–54|bibcode = 2005PreR..140...36K}}</ref><ref>{{cite journal |doi = 10.1016/j.precamres.2005.05.006|title = Combined micro-Fourier transform infrared (FTIR) spectroscopy and micro-Raman spectroscopy of Proterozoic acritarchs: A new approach to Palaeobiology|year = 2005|last1 = Marshall|first1 = C.|last2 = Javaux|first2 = E.|last3 = Knoll|first3 = A.|last4 = Walter|first4 = M.|journal = Precambrian Research|volume = 138|issue = 3–4|pages = 208–224|bibcode = 2005PreR..138..208M}}</ref><ref>{{cite journal |doi = 10.4202/app.2008.0060|title = Spore-Like Bodies in Some Early Paleozoic Acritarchs: Clues to Chlorococcalean Affinities|year = 2009|last1 = Kaźmierczak|first1 = Józef|last2 = Kremer|first2 = Barbara|journal = Acta Palaeontologica Polonica|volume = 54|issue = 3|pages = 541–551|doi-access = free}}</ref><ref>{{cite journal |doi = 10.1666/09-134.1|title = Confocal laser scanning microscopy and Raman imagery of the late Neoproterozoic Chichkan microbiota of South Kazakhstan|year = 2010|last1 = Schopf|first1 = J. William|last2 = Kudryavtsev|first2 = Anatoliy B.|last3 = Sergeev|first3 = Vladimir N.|journal = Journal of Paleontology|volume = 84|issue = 3|pages = 402–416| bibcode=2010JPal...84..402S |s2cid = 130041483}}</ref> has shown that some acritarchs are actually fossilized [[microalgae]]. In the end, it may well be, as Moczydłowska et al. suggested in 2011, that many acritarchs will, in fact, turn out to be algae.<ref>{{cite journal |doi = 10.1111/j.1475-4983.2011.01054.x|title = Proterozoic phytoplankton and timing of Chlorophyte algae origins|year = 2011|last1 = Moczydłowska|first1 = Małgorzata|last2 = Landing|first2 = ED|last3 = Zang|first3 = Wenlong|last4 = Palacios|first4 = Teodoro|journal = Palaeontology|volume = 54|issue = 4|pages = 721–733| bibcode=2011Palgy..54..721M |doi-access = free}}</ref><ref name=Chamberlain2016>{{cite journal |doi = 10.3390/geosciences6040057|title = A Mineralized Alga and Acritarch Dominated Microbiota from the Tully Formation (Givetian) of Pennsylvania, USA|year = 2016|last1 = Chamberlain|first1 = John|last2 = Chamberlain|first2 = Rebecca|last3 = Brown|first3 = James|journal = Geosciences|volume = 6|issue = 4|page = 57|bibcode = 2016Geosc...6...57C|doi-access = free}} [[File:CC-BY icon.svg|50px]] Material was copied from this source, which is available under a [https://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International License].</ref>