Emplectopteridaceae
Encyclopedia
The Emplectopteridaceae were pteridosperms known mainly from Permian
floras of the Cathaysian Realm. They were mostly shrubby plants with a scrambling or upright habit, and favoured a range of habitats from arid to moist or even aquatic. The foliage is the most abundant known remains of this family, having been reported from Artinskian
to Wuchiapingian
macroflora
s of both north and south China
. The venation is characteristically flexuous to loosely anastomosed
, and rather different from the more regularly anastomosed venation of the true gigantopterid
s (with which the Emplctopteridaceae fronds used to be confused). The stratigraphically older leaves tended to be twice pinnate
(Emplectopteris), the later leaves once pinnate or entire (Gigantonoclea). The ovule
s were bilateral and attached to the underside of the leaves / fronds that did not differ significantly from normal vegetative foliage Pollen organs were a complex of filiform
microsporophylls each bearing 2-8 sporangia (assigned to the fossil-genus Jiaochengia).
The family is currently only known from adpression
s (compression-impressions) and the consequential lack of anatomical evidence has resulted in some disagreement as to its affinities. However, the form and position of attachment of the ovules strongly suggests affinities with the callistophytalean
s.
The family is only reliably reported from China. Gigantonoclea-like leaves have also been reported from Permian macrofloras of North America
but without any evidence of reproductive structures and the affiniity of these leaves may lie nearer to the Peltaspermales..
Permian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...
floras of the Cathaysian Realm. They were mostly shrubby plants with a scrambling or upright habit, and favoured a range of habitats from arid to moist or even aquatic. The foliage is the most abundant known remains of this family, having been reported from Artinskian
Artinskian
In the geologic timescale, the Artinskian is an age or stage of the Permian. It is a subdivision of the Cisuralian epoch or series. The Artinskian lasted between 284.4 ± 0.7 and 275.6 ± 0.7 million years ago...
to Wuchiapingian
Wuchiapingian
In the geologic timescale, the Wuchiapingian or Wujiapingian is an age or stage of the Permian. It is also the lower or earlier of two subdivisions of the Lopingian epoch or series. The Wuchiapingian spans the time between 260.4 ± 0.7 and 253.8 ± 0.7 million years ago...
macroflora
Macroflora
Macroflora is a term used for all the plants occurring in a particular area that are large enough to be seen with the naked eye. It is usually synonymous with the Flora and can be contrasted with the microflora, a term used for all the bacteria and other microorganisms in an ecosystem.Macroflora is...
s of both north and south China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
. The venation is characteristically flexuous to loosely anastomosed
Anastomosis
An anastomosis is the reconnection of two streams that previously branched out, such as blood vessels or leaf veins. The term is used in medicine, biology, mycology and geology....
, and rather different from the more regularly anastomosed venation of the true gigantopterid
Gigantopterid
Gigantopterids is the name given to fossils of a group of plants existing in the Late Permian, some . Gigantopterids were among the most advanced land plants of the Paleozoic and disappeared soon after the massive Permian–Triassic extinction event...
s (with which the Emplctopteridaceae fronds used to be confused). The stratigraphically older leaves tended to be twice pinnate
Pinnate
Pinnate is a term used to describe feather-like or multi-divided features arising from both sides of a common axis in plant or animal structures, and comes from the Latin word pinna meaning "feather", "wing", or "fin". A similar term is pectinate, which refers to a comb-like arrangement of parts...
(Emplectopteris), the later leaves once pinnate or entire (Gigantonoclea). The ovule
Ovule
Ovule means "small egg". In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: The integument forming its outer layer, the nucellus , and the megaspore-derived female gametophyte in its center...
s were bilateral and attached to the underside of the leaves / fronds that did not differ significantly from normal vegetative foliage Pollen organs were a complex of filiform
Filiform
Filiform can refer to:*Filiform, a common term used in botany to described leaf shapes.*Filiform papilla on the tongue.*Thread-like crystal formations*A corrosion mechanism...
microsporophylls each bearing 2-8 sporangia (assigned to the fossil-genus Jiaochengia).
The family is currently only known from adpression
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
s (compression-impressions) and the consequential lack of anatomical evidence has resulted in some disagreement as to its affinities. However, the form and position of attachment of the ovules strongly suggests affinities with the callistophytalean
Callistophytales
The Callistophytales was an order of mainly scrambling and lianescent plants found in the wetland "coal swamps" of Euramerica and Cathaysia. They were characterised by having bilaterally-symmetrical, non-cupulate ovules attached to the underside of pinnules that were morphologically similar to the...
s.
The family is only reliably reported from China. Gigantonoclea-like leaves have also been reported from Permian macrofloras of North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
but without any evidence of reproductive structures and the affiniity of these leaves may lie nearer to the Peltaspermales..
External links
- http://www.nrm.se/images/18.494d73201246d535da780004643/S138197-p04+Emplectopteris+triangularis.jpg
- http://www.plantbiology.siu.edu/plb304/lecture08gymnos/images/1034.JPG