View source for Tempskya

{{Short description|Extinct genus of ferns}}
{{Automatic taxobox
| fossil_range = Cretaceous {{fossil range|Valanginian|Santonian}}
| image = Tempskya.jpg
| image_caption = ''Tempskya'' fossil slab and reconstruction on display
| taxon = Tempskya
| authority = [[August Carl Joseph Corda|Corda]] 1845<ref name=jstor>{{cite journal|last=Tidwell|first=William D.|author2=Hebbert, Naomi |title=Species of the Cretaceous Tree Fern ''Tempskya'' from Utah|journal=[[International Journal of Plant Sciences]]|date=September 1992|volume=153|issue=3|pages=513–528|doi=10.1086/297057|jstor=2995693|s2cid=55654367|url=http://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=2446&context=facpub}}</ref>
| parent_authority = Read et Brown ex L.C.A. Martínez
| display_parents = 3
}}
'''''Tempskya''''' is an [[Extinction|extinct]] [[genus]] of [[tree fern]] that lived during the [[Cretaceous|Cretaceous period]]. Fossils have been found across both the Northern and Southern hemispheres.<ref name=pimt>{{cite book|last=Gee|first=Carole T.|title=Plants in Mesozoic time : morphological innovations, phylogeny, ecosystems|year=2010|publisher=Indiana University Press|location=Bloomington|isbn=978-0-253-35456-3|chapter-url=https://books.google.com/books?id=FHcR3osfkxMC&pg=PA271|edition=illustrated|accessdate=25 January 2012|page=271|chapter=Oldest Known Dicotyledonous Lianas From the Early Late Cretaceous of Utah and New Mexico, U.S.A.}}</ref> The growth habit of ''Tempskya'' was unlike that of any living fern or any other living plant, consisting of multiple conjoined [[dichotomous branching]] stems enmeshed within roots that formed a "false [[Trunk (botany)|trunk]]".<ref name=":0">{{Cite journal|last=Martínez|first=Leandro C.A.|last2=Olivo|first2=Mariana S.|date=August 2015|title=Tempskya in the Valanginian of South America (Mulichinco Formation, Neuquén Basin, Argentina) — Systematics, palaeoclimatology and palaeoecology|url=https://linkinghub.elsevier.com/retrieve/pii/S003466671500069X|journal=Review of Palaeobotany and Palynology|language=en|volume=219|pages=116–131|doi=10.1016/j.revpalbo.2015.04.002|hdl=11336/49538|hdl-access=free}}</ref>
==Description==
The [[Trunk (botany)|trunk]] of ''Tempskya'' was actually a large collection of [[Plant stem|stems]] surrounded by [[Root#Specialized|adventitious roots]].<ref name="dk">{{cite book|last=Palmer|first=Douglas|title=[[Prehistoric Life (book)|Prehistoric life : the definitive visual history of life on earth]]|publisher=[[Dorling Kindersley]]|year=2009|isbn=978-0-7566-5573-0|edition=1st American|location=New York|page=286|display-authors=etal}}</ref> The false trunks can reach up to {{Convert|6|m|ft}} in height and up to {{Convert|50|cm|in}} in diameter.<ref name=":1">{{Cite journal|last=Yang|first=Xiaonan|last2=Liu|first2=Fengxiang|last3=Cheng|first3=Yeming|date=April 2018|title=A new tree fern stem, Tempskya zhangii sp. nov. (Tempskyaceae) from the Cretaceous of Northeast China|url=https://linkinghub.elsevier.com/retrieve/pii/S0195667117303026|journal=Cretaceous Research|language=en|volume=84|pages=188–199|doi=10.1016/j.cretres.2017.11.016}}</ref> Small leaves grew from various points across the height of the trunk. This is in contrast to most [[tree fern]]s, where typically large leaves grow from the top of the trunk.<ref name=":1" /> Thin [[Leaf|leaves]] have been discovered for the first time on ''Tempskya wyomingense'' specimens;<ref name=jstor/> the more commonly seen [[fossil]]ized [[Petiole (botany)|leaf bases]] show that they covered the upper part of the trunk.<ref name=dk/>
===Hypothesized growth pattern===
Examination of cross sections of various ''Tempskya'' specimens shows that those with the largest trunks have the smallest number of stems, and vice versa.<ref name="pb">{{cite book|last=Taylor|first=Thomas N.|title=Paleobotany : the biology and evolution of fossil plants|author2=Taylor, Edith L.|author3=Krings, Michael|publisher=Academic Press|year=2009|isbn=978-0-12-373972-8|edition=2nd|location=Amsterdam|pages=457–459|chapter=Ferns and Early Fernlike Plants|chapter-url=https://books.google.com/books?id=_29tNNeQKeMC&pg=PA457|accessdate=24 January 2012}}</ref> From this, a possible growth pattern of ''Tempskya'' has been suggested: at the [[sporeling]] stage, ''Tempskya'' would consist of a single stem, which would begin to branch off distally. A "mantle" of adventitious roots would then develop around the stems to support them. Later on, many of the stems would begin to [[Decomposition|decay]], while the adventitious roots would still provide support and absorb water for the grown plant.<ref name=pb/> This growth pattern has also been hypothesized for ''[[Psaronius]]''.<ref name=pb/>
=== Ecology ===
''Tempskya'' is thought to have grown in lowland environments close to water, like [[wetland]]s and riverbanks.<ref name=":0" />
==Taxonomy==
[[File:Tempskya sp. - MUSE.jpg|thumb|''Tempskya'' sp. - Reconstruction at [[MUSE - Science Museum]] in [[Trento]]]]
The first fossils of ''Tempskya'' was originally described in 1824 as the ''Endogenites erosa'' by Stokes and Webb, who considered it to be a [[palm tree]]. The genus ''Tempskya'' was named by [[August Carl Joseph Corda]] in 1845, from specimens found in what is now the Czech Republic.<ref name=jstor/> The four [[species]] originally described by Corda were, in order: ''Tempskya pulchra'', ''Tempskya macrocaula'', ''Tempskya microrrhiza'', and ''Tempskya schimperi''.<ref>{{cite book|last=Stephenson|first=Lloyd William|title=New Upper Cretaceous Ostreidae From the Gulf Region|year=1936|publisher=United States Government Printing Office|location=Washington|chapter-url=https://books.google.com/books?id=P0IRAAAAIAAJ&pg=PA108|chapter=American Cretaceous Ferns of the Genus Tempskya|accessdate=25 January 2012|page=108}}</ref>
''Tempskya'' is the sole member of the family Tempskyaceae.<ref name=dk/> The family has been placed in the order "Filicales",<ref name=pb/> which is now split into a number of orders of [[leptosporangiate fern]]s. They have been suggested to members of [[Cyatheales]], based on morphological similarities of the [[Petiole (botany)|petiole]] and spores to some members of that order.<ref name=":0"/>
=== Species ===
Most taxonomists divide ''Tempskya'' species into two groups, those with a simple cortex with only a [[Ground tissue#Parenchyma|parenchymatous]] inner cortex without [[Ground tissue|sclerenchyma]], while other species have an inner cortex with either discontinuous or continuous layers of sclerenchyma.<ref name=":1"/>
* Parenchymatous inner cortex group:
** ''Tempskya iwatensis'' Nishida, 1986 [[Taneichi Formation]], Japan, Late Cretaceous ([[Santonian]])
** ''Tempskya rossica'' Kidston and Gwynne Vaughan, 1911 [[Mugodzhar Hills|Mugadjar]], Kazakhstan, Upper Cretaceous?
** ''Tempskya uemurae'' Nishida, 2001 Taneichi Formation, Japan, Late Cretaceous (Santonian)
** ''Tempskya dernbachii''  Tidwell et Wright, 2003 emend. Martínez, Martínez and Olivo, 2015 [[Mulichinco Formation]], Argentina, Early Cretaceous ([[Valanginian]])<ref name=":0" />
** ''Tempskya zellerii'' Ash et Read, Ash and Read, 1976  [[Mojado Formation]], New Mexico, United States, Early Cretaceous ([[Albian]])
** ''Tempskya minor'' Read and Brown, 1937 [[Bear River Formation]], Wyoming, United States, Late Cretaceous
** ''Tempskya jonesii'' Tidwell and Hebbert, 1992 [[Cedar Mountain Formation]], [[Burro Canyon Formation]], [[Dakota Formation]], Utah, United States, Cretaceous (Albian-[[Cenomanian]])
** ''Tempskya knowltonii'' Seward, 1924 Montana and Utah (possibly [[Kootenai Formation]]) United States, Early Cretaceous
* Continuous bands of sclerenchyma in the inner cortex group:
** ''Tempskya grandis'' Read and Brown 1937 Bear River Formation, Wyoming, United States, Late Cretaceous
** ''Tempskya superba'' Arnold, 1958 [[Dawes County]], [[Nebraska]] (possibly [[Lakota Formation]]) United States, Early Cretaceous?
** ''Tempskya reesidei'' Ash and Read, 1976 Mojado Formation, New Mexico, United States, Early Cretaceous (Albian)
** ''Tempskya readii'' Tidwell and Hebbert 1992 Burro Canyon Formation, Utah, United States, mid Cretaceous
** ''Tempskya riojana'' Barale and Viera, 1989 [[Enciso Group]], Spain, Early Cretaceous (Valanginian to [[Barremian]])
** ''Tempskya wesselii'' Arnold,1945 Kootenai Formation, Montana, Oregon and Utah, United States, Early Cretaceous
** ''Tempskya judithae'' Clifford and Dettmann, 2005 [[Winton Formation]], Australia, Early Cretaceous (Albian)
** ''Tempskya stichkae'' Tidwell and Hebbert,1992 Cedar Mountain Formation, Burro Canyon Formation, Utah, United States, Early Cretaceous (Albian)
**''Tempskya wyomingensis'' Arnold, 1945 Utah, Wyoming and Colorado, United States, Lower Cretaceous?
** ''Tempskya zhangii'' Yang, Liu et Cheng, 2017 Songliao Basin, Heliongjiang, China, Cretaceous<ref name=":1"/>
* ''Incertae sedis:''
** ''Tempskya pulchra'' Corda, 1845 Czech Republic, Cretaceous
** ''Tempskya schimperi'' Corda, 1845 Germany, Czech Republic, France, Lower Cretaceous
**''Tempskya varians'' Velenovsky, 1888  Czech Republic, Cenomanian (?)
** ''Tempskya cretacea'' Hosius and Marck, 1880, [[Westfalia]], Germany, Late Cretaceous
** ''Tempskya erosa'' ,Stokes et Webb, 1915, [[Lower Greensand Group]], England, Lower Cretaceous
** ''Tempskya whitei'' Berry, 1991, [[Patapsco Formation]], Maryland, United States, Lower Cretaceous
==Fossil sites==
''Tempskya'' finds were thought to be exclusive to the Northern Hemisphere until specimens were discovered in Argentina and Australia, in 2003 and 2005, respectively. ''Tempskya'' fossils have also been discovered in the [[Czech Republic]] ,2002 and [[Japan]] ,1986.<ref name=pimt/>
==References==
{{Reflist}}
{{Taxonbar|from=Q3983361}}
[[Category:Cretaceous plants]]
[[Category:Polypodiales|† Tempskya]]
[[Category:Ferns of Argentina]]
[[Category:Fossil taxa described in 1845]]