Editing Phasmatodea (section)

==Taxonomy==
[[File:Phyllium bilobatum, male larva.jpg|thumb|upright|True leaf insects, like this ''[[Phyllium bilobatum]]'', belong to the family [[Phylliidae]].]]
The classification of the Phasmatodea is complex and the relationships between its members are poorly understood.<ref>{{cite web |url=http://www.phasmatodea.com/web/guest/classification |title=Classification of the Phasmatodea |publisher=Phasmatodea.com |access-date=2 October 2015 |archive-url=https://web.archive.org/web/20151003130026/http://www.phasmatodea.com/web/guest/classification |archive-date=3 October 2015 |url-status=dead}}</ref> Furthermore, there is much confusion over the ordinal name. Phasmida is preferred by many authors, though it is [[International Code of Zoological Nomenclature|incorrectly formed]];{{citation needed|date=August 2019}} Phasmatodea is correctly formed, and is widely accepted.<ref name=Zompro/> However, Brock and Marshall argue:<ref>{{cite book |first1=Paul D. |last1=Brock |first2=Judith |last2=Marshall |year=2011 |chapter=Order Phasmida Leach. 1815. |editor-last1= Zhang |editor-first1=Z.-Q. |title=Animal biodiversity: An outline of higherlevel classification and survey of taxonomic richness |chapter-url=https://www.mapress.com/zootaxa/2011/f/zt03148p198.pdf}}</ref>

{{blockquote|Phasmida is the oldest and simplest name, first used by Leach in 1815 in "Brewster’s Edinburgh Encyclopaedia" volume 9, p.&nbsp;119, and widely used in major entomological textbooks, dictionaries and many scientific papers and books on phasmids. As there is no compulsion to select the "grammatically correct" name [which some argue is Phasmatodea Jacobson & Bianchi, 1902], selection of a long established (and simple) name is reasonable, although the probability of persuading all colleagues to agree on the use of Phasmida is unlikely.}}

The order Phasmatodea is sometimes considered to be related to other orders, including the [[Blattodea]], [[Mantodea]], [[Grylloblattodea]], [[Mantophasmatodea]] and [[Dermaptera]], but the affiliations are uncertain and the grouping (sometimes referred to as "Orthopteroidea") may be [[paraphyletic]] (not have a common ancestor) and hence invalid in the traditional [[Circumscription (taxonomy)|circumscription]] (set of attributes that all members have). Phasmatodea, once considered a suborder of [[Orthoptera]], is now treated as an order of its own.<ref name=PSF>{{cite web|last1=Brock|first1=Paul D.|title=Phasmida Species File Online. Version 5.0|url=http://phasmida.speciesfile.org/HomePage/Phasmida/HomePage.aspx|access-date=2 October 2015}}</ref> Anatomical features separate them as a [[monophyletic]] (descended from a common ancestor) group from the Orthoptera. One is the instance among all species of Phasmatodea of a pair of [[exocrine gland]]s inside the prothorax used for defense. Another is the presence of a specially formed [[sclerite]] (hardened plate), called a vomer, which allows the male to clasp the female during mating.<ref name="Oxford Reference Online">{{cite book |last=O'Toole |first=Christopher |title=Leaf and Stick Insects |year=2002 |url=https://www.oxfordreference.com/view/10.1093/acref/9780198525059.001.0001/acref-9780198525059-e-18?rskey=jmOpW1&result=1 |publisher=Oxford University Press|isbn=978-0-19-852505-9 }}</ref>

The order is divided into two, or sometimes three, suborders.<ref name="Oxford Reference Online" /> The traditional division is into the suborder groups Anareolatae and Areolatae, which are distinguished according to whether the insect has sunken areola, or circular areas, on the underside of the apices of the middle and hind tibiae (Areolate) or not (Anareolate). However the [[phylogenetic]] (evolutionary) relationships between the different groups is poorly resolved. The [[monophyly]] of Anareolatae has been questioned and the [[Morphology (biology)|morphology]] of the eggs may be a better basis for classification.<ref name=Zompro>{{cite journal |author=Zompro, O. |year=2004 |title=Revision of the genera of the Areolatae, including the status of ''Timema'' and ''Agathemera'' (Insecta: Phasmatodea) |journal=Organización Para Estudios Tropicales, (OET), Costa Rica Bibliografía Nacional en Biología Tropical (BINABITROP) |volume=37 |pages=1–327 |url=http://www.sidalc.net/cgi-bin/wxis.exe/?IsisScript=OET.xis&method=post&formato=2&cantidad=1&expresion=mfn=027215 |archive-url=https://web.archive.org/web/20151003180430/http://www.sidalc.net/cgi-bin/wxis.exe/?IsisScript=OET.xis&method=post&formato=2&cantidad=1&expresion=mfn=027215 |archive-date=3 October 2015 |url-status=dead}}</ref> An alternative is to divide the Phasmatodea into three suborders [[Agathemerodea]] (1 genus and 8 species), [[Timematodea]] (1 genus and 21 species) and [[Euphasmatodea]] (or Verophasmatodea) for the remaining [[taxa]].<ref name=Biodiversity>{{cite book|title=Animal biodiversity: An outline of higher-level classification and survey of taxonomic richness |url=https://books.google.com/books?id=r3_DVd5DtGEC&pg=PA198 |year=2011 |publisher=Magnolia Press |isbn=978-1-86977-849-1 |page=198}}</ref> This division is, however, not fully supported by the molecular studies, which recover Agathemerodea as nested within Euphasmatodea rather than being the sister group of the latter group.<ref>{{Cite journal|author1=Thomas R. Buckley |author2=Dilini Attanayake |author3=Sven Bradler |year=2009 |title=Extreme convergence in stick insect evolution: phylogenetic placement of the Lord Howe Island tree lobster |journal=Proceedings of the Royal Society B: Biological Sciences |volume=276 |issue=1659 |pages=1055–1062 |doi=10.1098/rspb.2008.1552 |pmid=19129110 |pmc=2679072}}</ref><ref>{{Cite journal|author1=Sven Bradler |author2=James A. Robertson |author3=Michael F. Whiting |year=2014 |title=A molecular phylogeny of Phasmatodea with emphasis on Necrosciinae, the most species-rich subfamily of stick insects |journal=Systematic Entomology |volume=39 |issue=2 |pages=205–222 |doi=10.1111/syen.12055 |bibcode=2014SysEn..39..205B |s2cid=85794995}}</ref><ref name=SF-Phasmida>{{cite speciesfile|phasmida|id=851140 |title=Phasmida Leach, 1815 |access-date=15 June 2024}}</ref> Recent taxonomic treatments recognise two suborders,<ref name=SF-Phasmida/> with [[Agathemeridae]] placed in [[Pseudophasmatoidea]] within Euphasmatodea<ref>{{cite speciesfile|phasmida|id=852046 |title=Agathemeridae Bradler, 2003|access-date=15 June 2024}}</ref> and Agathemerodea treated as ''[[nomen dubium]]''<ref>{{cite speciesfile|phasmida|id=851143 |title=Agathemerodea Zompro, 2004|access-date=15 June 2024}}</ref>

While suggestions have been made that various insects extending back to the [[Permian]] epoch represent stem-group phasmatodeans, the earliest unambiguous members of the group are the [[Susumanioidea]], which first appeared during the Middle [[Jurassic Park|Jurassic]], and usually have two large pairs of wings. Modern phasmatodeans first appeared during the Early [[Cretaceous]], with the currently oldest known being ''[[Araripephasma]]'' from the Early Cretaceous ([[Aptian]]) [[Crato Formation]] of Brazil, around 113 million years old, which can be confidently assigned to the Euphasmatodea.<ref>{{Cite journal |last1=Ghirotto |first1=Victor M. |last2=Crispino |first2=Edgar B. |last3=Chiquetto-Machado |first3=Pedro I. |last4=Neves |first4=Pedro A. B. A. |last5=Engelking |first5=Phillip W. |last6=Ribeiro |first6=Guilherme C. |date=May 2022 |editor-last=Labandeira |editor-first=Conrad |title=The oldest Euphasmatodea (Insecta, Phasmatodea): modern morphology in an Early Cretaceous stick insect fossil from the Crato Formation of Brazil |url=https://onlinelibrary.wiley.com/doi/10.1002/spp2.1437 |journal=Papers in Palaeontology |language=en |volume=8 |issue=3 |doi=10.1002/spp2.1437 |bibcode=2022PPal....8E1437G |s2cid=249738376 |issn=2056-2799|url-access=subscription }}</ref>

The earliest leaf insect (Phylliinae) fossil is ''[[Eophyllium messelensis]]'' from the 47-million-year-old [[Eocene]] of Messel, Germany. In size and cryptic (leaflike) body form, it closely resembles extant species, suggesting that the behavior of the group has changed little since that time.<ref>{{cite journal |last1=Wedmann |first1=Sonja |last2=Bradler |first2=Sven |last3=Rust |first3=Jes |title=The first fossil leaf insect: 47 million years of specialized cryptic morphology and behavior |journal=PNAS |date=2006 |volume=104 |issue=2 |pages=565–569 |doi=10.1073/pnas.0606937104 |pmid=17197423 |pmc=1766425|doi-access=free }}</ref>

Over 3,500 species have been described, with many more yet to be described both in museum collections and in the wild.<ref>Bragg, P.E. (2001) ''Phasmids of Borneo'', Natural History Publications (Borneo), Kota Kinabalu. - see p. 614.</ref><ref name=SF-Phasmida/>

{| class="wikitable" style="margin:auto; width:100%;"
!Suborders
!No. of species
!Defining notes
!Image
|-
|[[Timematodea]]
|21<ref>{{cite speciesfile|phasmida|id=851144 |title=Timematodea Kevan, 1977|access-date=15 June 2024}}</ref> 
|Considered earliest to branch from phylogenetic tree
|[[File:Timema dorotheae.jpg|thumb|center|upright|''Timema dorotheae'']]
|-
|[[Euphasmatodea]]
|3514<ref>{{cite speciesfile|phasmida|id=851173 |title=Euphasmatodea Bradler, 1999|access-date=15 June 2024}}</ref> 
|Vast majority of extant species
|[[File:DonovanEpitomePlate9.jpg|thumb|center|upright|''Phasma gigas'']]
|}