Yunia: Difference between revisions
Content deleted Content added
m corrected my typo |
additional material |
||
| Line 7: | Line 7: | ||
| unranked_classis = [[Tracheophyta]] |
| unranked_classis = [[Tracheophyta]] |
||
| genus= † '''''Yunia''''' |
| genus= † '''''Yunia''''' |
||
| genus_authority = Hao & Beck (1991)<ref>{{Citation |last=Hao |first=Shou-Gang |last2=Beck |first2=Charles B. |year=1991 |title=''Yunia dichotoma'', a Lower Devonian plant from Yunnan, China |journal=Review of Palaeobotany and Palynology |volume=68 |issue=3-4 |pages=181–195 |doi=10.1016/0034-6667(91)90022-U |lastauthoramp=yes }}</ref> |
| genus_authority = Hao & Beck (1991)<ref name="HaoBeck1991">{{Citation |last=Hao |first=Shou-Gang |last2=Beck |first2=Charles B. |year=1991 |title=''Yunia dichotoma'', a Lower Devonian plant from Yunnan, China |journal=Review of Palaeobotany and Palynology |volume=68 |issue=3-4 |pages=181–195 |doi=10.1016/0034-6667(91)90022-U |lastauthoramp=yes }}</ref> |
||
| subdivision_ranks = Species |
| subdivision_ranks = Species |
||
| subdivision = † ''Y. dichotoma'' <small>Hao & Beck (1991)</small> |
| subdivision = † ''Y. dichotoma'' <small>Hao & Beck (1991)</small> |
||
}} |
}} |
||
'''''Yunia''''' is a genus of extinct [[vascular plant]]s from the [[Early Devonian]] (the [[Pragian]] stage, around 410 million years ago). The leafless plant consisted of spiny stems which branched dichotomously in a cruciate arrangement. Each stem contained [[vascular tissue]] with one or two strands of [[Xylem#Primary_and_secondary_xylem|protoxylem]]. The spore-forming organs ([[Sporangium|sporangia]]) were elongated. The spores had a relatively smooth sculptural pattern and were trilete (i.e. each spore has three lines on it resulting from its formation in a tetrahedral set of four spores).<ref>{{Citation |last=Taylor |first=T.N. |last2=Taylor |first2=E.L. |last3=Krings |first3=M. |year=2009 |title=Paleobotany : The Biology and Evolution of Fossil Plants |edition=2nd |publication-place=Amsterdam; Boston |publisher=Academic Press |isbn=978-0-12-373972-8 |lastauthoramp=yes }}, p. 262</ref> |
'''''Yunia''''' is a genus of extinct [[vascular plant]]s from the [[Early Devonian]] (the [[Pragian]] stage, around 410 million years ago). It was first described from the Posonchong Formation (Siegenian) of [[Yunnan]], China. The leafless plant consisted of spiny stems, some 2 to 5 cm wide, which branched dichotomously at wide angles in a cruciate arrangement. Each stem contained [[vascular tissue]] with one or two strands of [[Xylem#Primary_and_secondary_xylem|protoxylem]]. The spore-forming organs ([[Sporangium|sporangia]]) were elongated and borne on short stalks. The spores had a relatively smooth sculptural pattern and were trilete (i.e. each spore has three lines on it resulting from its formation in a tetrahedral set of four spores).<ref name="HaoBeck1991"/><ref>{{Citation |last=Taylor |first=T.N. |last2=Taylor |first2=E.L. |last3=Krings |first3=M. |year=2009 |title=Paleobotany : The Biology and Evolution of Fossil Plants |edition=2nd |publication-place=Amsterdam; Boston |publisher=Academic Press |isbn=978-0-12-373972-8 |lastauthoramp=yes }}, p. 262</ref> It was initially tentatively assigned to the "[[trimerophyte]]s".<ref name="HaoBeck1991"/> |
||
In 2004, Crane et al. published a simplified [[cladogram]] for the [[polysporangiophyte]]s in which ''Yunia'' is basal to the [[Lycopodiophyta|lycophytes]] (clubmosses and relatives).<ref>{{Citation |last=Crane |first=P.R. |last2=Herendeen |first2=P. |last3=Friis |first3=E.M. |year=2004 |title=Fossils and plant phylogeny |journal=American Journal of Botany |volume=91 |pages=1683–99 |url=http://www.amjbot.org/cgi/content/full/91/10/1683 |accessdate=2011-01-27 |doi=10.3732/ajb.91.10.1683}}</ref> It had previously been placed in the '[[trimerophyte]]s' (a group now thought to be paraphyletic) which were considered to have given rise to all the other vascular plants ''except'' the lycophytes.<ref>{{Harvnb|Taylor|Taylor|Krings|2009|p=259ff.}}</ref> |
In 2004, Crane et al. published a simplified [[cladogram]] for the [[polysporangiophyte]]s in which ''Yunia'' is basal to the [[Lycopodiophyta|lycophytes]] (clubmosses and relatives).<ref>{{Citation |last=Crane |first=P.R. |last2=Herendeen |first2=P. |last3=Friis |first3=E.M. |year=2004 |title=Fossils and plant phylogeny |journal=American Journal of Botany |volume=91 |pages=1683–99 |url=http://www.amjbot.org/cgi/content/full/91/10/1683 |accessdate=2011-01-27 |doi=10.3732/ajb.91.10.1683}}</ref> It had previously been placed in the '[[trimerophyte]]s' (a group now thought to be paraphyletic) which were considered to have given rise to all the other vascular plants ''except'' the lycophytes.<ref>{{Harvnb|Taylor|Taylor|Krings|2009|p=259ff.}}</ref> |
||
Revision as of 14:06, 7 February 2011
| Yunia Temporal range: Early Devonian
| |
|---|---|
| Scientific classification | |
| Kingdom: | |
| Subkingdom: | |
| (unranked): | |
| (unranked): | |
| Genus: | † Yunia Hao & Beck (1991)[1]
|
| Species | |
|
† Y. dichotoma Hao & Beck (1991) | |
Yunia is a genus of extinct vascular plants from the Early Devonian (the Pragian stage, around 410 million years ago). It was first described from the Posonchong Formation (Siegenian) of Yunnan, China. The leafless plant consisted of spiny stems, some 2 to 5 cm wide, which branched dichotomously at wide angles in a cruciate arrangement. Each stem contained vascular tissue with one or two strands of protoxylem. The spore-forming organs (sporangia) were elongated and borne on short stalks. The spores had a relatively smooth sculptural pattern and were trilete (i.e. each spore has three lines on it resulting from its formation in a tetrahedral set of four spores).[1][2] It was initially tentatively assigned to the "trimerophytes".[1]
In 2004, Crane et al. published a simplified cladogram for the polysporangiophytes in which Yunia is basal to the lycophytes (clubmosses and relatives).[3] It had previously been placed in the 'trimerophytes' (a group now thought to be paraphyletic) which were considered to have given rise to all the other vascular plants except the lycophytes.[4]
| tracheophytes |
| |||||||||||||||||||||
References
- ^ a b c Hao, Shou-Gang; Beck, Charles B. (1991), "Yunia dichotoma, a Lower Devonian plant from Yunnan, China", Review of Palaeobotany and Palynology, 68 (3–4): 181–195, doi:10.1016/0034-6667(91)90022-U
{{citation}}: Unknown parameter|lastauthoramp=ignored (|name-list-style=suggested) (help) - ^ Taylor, T.N.; Taylor, E.L.; Krings, M. (2009), Paleobotany : The Biology and Evolution of Fossil Plants (2nd ed.), Amsterdam; Boston: Academic Press, ISBN 978-0-12-373972-8
{{citation}}: Unknown parameter|lastauthoramp=ignored (|name-list-style=suggested) (help), p. 262 - ^ Crane, P.R.; Herendeen, P.; Friis, E.M. (2004), "Fossils and plant phylogeny", American Journal of Botany, 91: 1683–99, doi:10.3732/ajb.91.10.1683, retrieved 2011-01-27
- ^ Taylor, Taylor & Krings 2009, p. 259ff.
