Editing Gar (section)

=== Evolutionary history ===
[[File:HMNS gar.jpg|thumb|231x231px|''[[Atractosteus messelensis]]'', an [[Eocene]] gar from the [[Messel pit|Messel]] of [[Germany]]]]
[[File:MasillosteusJaneae.jpg|thumb|231x231px|''[[Masillosteus]]'', an Eocene gar from [[Fossil Butte National Monument|Fossil Butte]], [[Wyoming]]]]
Gars are considered to be the only surviving members of the [[Ginglymodi]], a group of [[Osteichthyes|bony fish]] that flourished in the [[Mesozoic]].<ref name="Nhanulepisosteus" /> The oldest known ginglymodians appeared during the [[Middle Triassic]], over 240&nbsp;million years ago.<ref>{{Cite journal|last=Romano|first=Carlo|date=2021|title=A Hiatus Obscures the Early Evolution of Modern Lineages of Bony Fishes|journal=Frontiers in Earth Science|volume=8|pages=672|doi=10.3389/feart.2020.618853|issn=2296-6463|doi-access=free}}</ref> Because they have the slowest known rate of molecular evolution among all jawed vertebrates, it has also slowed down their rate of speciation.<ref>[https://academic.oup.com/evolut/advance-article/doi/10.1093/evolut/qpae028/7615529?searchresult=1&login=false The genomic signatures of evolutionary stasis]</ref> The closest living relatives of gars are the [[Amia (fish)|bowfin]], with the gars and bowfin together forming the clade [[Holostei]]; both lineages diverged during the [[Late Permian]].<ref name=":9">{{Cite journal |last1=López-Arbarello |first1=Adriana |last2=Sferco |first2=Emilia |date=March 2018 |title=Neopterygian phylogeny: the merger assay |journal=Royal Society Open Science |language=en |volume=5 |issue=3 |pages=172337 |doi=10.1098/rsos.172337 |issn=2054-5703 |pmc=5882744 |pmid=29657820|bibcode=2018RSOS....572337L }}</ref>

The closest extinct relatives of gar are the [[Obaichthyidae]], an extinct group of gar-like fishes from the [[Early Cretaceous]] of Africa and South America, which likely diverged from the ancestors of true gars during the [[Late Jurassic]]. The oldest anatomically modern gar is ''[[Nhanulepisosteus]]'' from the Upper Jurassic ([[Kimmeridgian]]) of [[Mexico]], around 157 million years old. ''Nhanulepisosteus'' inhabited a marine environment unlike modern gars, indicating that gars may have originally been marine fish prior to invading freshwater habitats before the Early Cretaceous.<ref name="Nhanulepisosteus">{{Cite journal|author1=Paulo M. Brito|author2=Jésus Alvarado-Ortega|author3=François J. Meunier|year=2017|title=Earliest known lepisosteoid extends the range of anatomically modern gars to the Late Jurassic|journal=Scientific Reports|volume=7|issue=1|pages=Article number 17830|bibcode=2017NatSR...717830B|doi=10.1038/s41598-017-17984-w|pmc=5736718|pmid=29259200}}</ref><ref name=":7">{{Cite journal |last1=Brownstein |first1=Chase Doran |last2=Yang |first2=Liandong |last3=Friedman |first3=Matt |last4=Near |first4=Thomas J. |date=20 December 2022 |title=Phylogenomics of the Ancient and Species-Depauperate Gars Tracks 150 Million Years of Continental Fragmentation in the Northern Hemisphere |url=https://academic.oup.com/sysbio/article-abstract/72/1/213/6946847 |journal=Systematic Biology |volume=72 |issue=1 |pages=213–227 |doi=10.1093/sysbio/syac080 |pmid=36537110 |access-date=2023-06-05 |via= }}</ref> Although most succeeding gar fossils are known from freshwater environments, at least some marine gars are known to have persisted into the [[Late Cretaceous]], with the likely marine ''[[Herreraichthys]]'' known from Mexico and the definitely marine ''[[Grandemarinus]]'' known from [[Morocco]].<ref>{{Cite journal |last1=Alvarado-Ortega |first1=Jesús |last2=Brito |first2=Paulo M. |last3=Porras-Múzquiz |first3=Héctor Gerardo |last4=Mújica-Monroy |first4=Irene Heidi |date=2016-01-01 |title=A Late Cretaceous marine long snout "pejelagarto" fish (Lepisosteidae, Lepisosteini) from Múzquiz, Coahuila, northeastern Mexico |url=https://www.sciencedirect.com/science/article/pii/S019566711530032X |journal=Cretaceous Research |volume=57 |pages=19–28 |doi=10.1016/j.cretres.2015.07.009 |bibcode=2016CrRes..57...19A |issn=0195-6671|url-access=subscription }}</ref><ref name="Cooper2023">{{cite journal |last1=Cooper |first1=S. L. A. |last2=Gunn |first2=J. |last3=Brito |first3=P. M. |last4=Zouhri |first4=S. |last5=Martill |first5=D. M. |date=2023 |title=A new fully marine, short-snouted lepisosteid gar from the Upper Cretaceous (Turonian) of North Africa |journal=Cretaceous Research |volume=151 |pages=105650 |doi=10.1016/j.cretres.2023.105650 |doi-access=free|bibcode=2023CrRes.15105650C }}</ref> 

Gars diversified in [[western North America]] throughout the Early Cretaceous. ''Atractosteus'' and ''Lepisosteus'' had already diverged by the end of the Early Cretaceous, about 105 million years ago. From western North America, gars dispersed to regions as disparate as Africa, India, South America and Europe, and fossil remains of gars were widespread worldwide by the end of the Cretaceous.<ref name=":7" />

Several different gar genera survived the [[Cretaceous–Paleogene extinction event]], although they remained restricted to North America and Europe after this point. One species (''[[Atractosteus grandei]]'', a relative of the modern [[alligator gar]]) is the oldest known articulated vertebrate specimen of the [[Cenozoic]], with one fossil specimen dated to just a few thousand years after the [[Chicxulub impact]], indicating a rapid recovery of freshwater ecosystems. Two short-snouted gar genera, ''[[Masillosteus]]'' and ''[[Cuneatus]]'', are known from the [[Eocene]] in western North America and Europe, but disappear shortly afterwards. ''Lepisosteus'' and ''Atractosteus'' show a similar initial distribution and eventual contraction, but both genera dispersed to [[Nearctic realm|eastern North America]] prior to their disappearance from western North America and Europe, with ''Atractosteus'' also dispersing further south to the [[Neotropical realm|Neotropics]]. Eastern North America has since served as a vital [[Refugium (population biology)|refugium]] for gars, with ''Lepisosteus'' undergoing a diversification throughout it.<ref name=":7" />