Archaeopteris is an extinct genus of tree-like ferns that many scientists believe to be the first tree. A useful index fossil, this tree is found in strata dating from the Upper Devonian to Lower Carboniferous. Fossils are found in Europe, North America, and Morocco in North Africa. Some specimines have also been reported from Australia. In biology and ecology, extinction is the ceasing of existence of a species or group of species. ... Classes Marattiopsida Osmundopsida Gleicheniopsida Pteridopsida A fern, or pteridophyte, is any one of a group of some twenty thousand species of plants classified in the Division Pteridophyta, formerly known as Filicophyta. ... The coniferous Coast Redwood, the tallest tree species on earth A tree can be defined as a large, perennial, woody plant. ... Index fossils (or zone fossils) are fossils used to define and identify geologic periods (or faunal stages). ... Interstate road cut through limestone and shale strata in eastern Tennessee In geology and related fields, a stratum (plural: strata) is a layer of rock or soil with internally consistent characteristics that distinguishes it from contiguous layers. ... The Devonian is a major division of the geologic timescale that extends from the end of the Silurian period (360 million years ago (mya)) to the beginning of the Mississippian subperiod of the Carboniferous (408. ... The Carboniferous is a major division of the geologic timescale that extends from the end of the Devonian period, about 340 million years ago (mya), to the beginning of the Permian period, about 280 mya. ... World map showing location of Europe A satellite composite image of Europe Europe is geologically and geographically a peninsula, forming the westernmost part of Eurasia. ... World map showing location of North America A satellite composite image of North America North America is the third largest continent in area and in population after Eurasia and Africa. ... The Kingdom of Morocco is a country in northwest Africa. ... North Africa is a region generally considered to include: Algeria Egypt Libya Mauritania Morocco Sudan Tunisia Western Sahara The Canary Islands, Ethiopia, Eritrea and Madeira are sometimes considered to be a part of North Africa. ... Australia, officially the Commonwealth of Australia, is the sixth-largest country in the world, the only country to occupy an entire continent, and the largest in the region of Australasia/Oceania. ...

Many scientists consider Archaeopteris to be the earliest known modern tree, with buds, reinforced branch joints, and branched trunks similar to today's timber. The genus Archaeopteris shares more characteristics with the seed plants than any other spore-bearing plant known. It combines characteristics of both woody trees and herbaceous ferns. Because they do not possess seeds, they are considered more closely related to modern tree ferns than to conifers. Timber Timber is a term used to describe clusters of trees. ... The term spore has several different meanings in biology. ... A herb (pronounced urb in American English and hurb in British English) is a plant grown for culinary or medicinal value. ... Tree Fern refers to any fern that grows with a trunk elevating the fronds above ground level. ... Orders & Families Cordaitales † Pinales   Pinaceae - Pine family   Araucariaceae - Araucaria family   Podocarpaceae - Yellow-wood family   Sciadopityaceae - Umbrella-pine family   Cupressaceae - Cypress family   Cephalotaxaceae - Plum-yew family   Taxaceae - Yew family Vojnovskyales † Voltziales † The conifers, division Pinophyta, are one of 13 or 14 division level taxa within the Kingdom Plantae. ...

Anatomy

The trees of this genus were small to medium in size with leafy foliage reminiscent of some conifers. The large fronds were thickly set with fan-shaped leaflets on stems that inclined sharply upward. They typically grew to 10 m in height. Some species are large, with trunks that exceeded 1.5 m in diameter. The veining branches diverged dichotomously. There was also intermediate feathering at each frond node or axes. A fern with simple (lobed or pinnatifid) blades, the dissection of each blade not quite reaching to the rachis. ...

Leafy shoots occurred in opposite arrangement in a single plane. The leaflets, or pinnules, overlapped one another and were subcircular to wedge-shaped. On fertile branches, the leaves were replaced by spore capsules.

Other modern adaptations

Aside from its woody trunk, Archaeopteris possessed other modern adaptations to light interception and perhaps to seasonality as well. The large umbrella of fronds seems to have been quite optimized for light interception at the canopy level. In some species, the pinnules were shaped and orientated to avoid shading one another. There is evidence that whole fronds were shed together as single units, perhaps on a seasonal basis like modern deciduous foliage or like trees in the cypress family Cupressaceae. Deciduous means temporary or tending to fall off (deriving from the Latin word decidere, to fall off). ... Genera Actinostrobus Athrotaxis Austrocedrus Callitris - Cypress-pine Callitropsis - Cypress * (Cupressus) Calocedrus - Incense-cedar Chamaecyparis - Cypress Cryptomeria - Sugi Cunninghamia - Cunninghamia Cupressus - Cypress Diselma - Diselma Fitzroya - Alerce Fokienia - Fujian Cypress Glyptostrobus - Chinese Swamp Cypress Juniperus - Juniper Libocedrus Metasequoia - Dawn Redwood Microbiota - Microbiota Neocallitropsis Papuacedrus * (Libocedrus) Pilgerodendron * (Libocedrus) Platycladus - Chinese Arborvitae Sequoia - Coast...

The plant also had nodal zones that would have been important sites for the subsequent development of lateral roots and branches. Some branches were latent and adventitious, similar to those produced by living trees that eventually develop into roots. Before this time, shallow, rhizomatious roots had been the norm, but with Archaeopteris, deeper root systems were being developed that could support ever higher growth. In botany, a rhizome is a horizontal, usually underground stem of a plant that often sends out roots and shoots from its nodes. ...

Habitat

Evidence indicates that Archaeopteris preferred wet soils, growing close to river systems and in flood plain woodlands. It would have formed a significant part of the canopy vegetation of early forests. Speaking of the first appearance of Archaeopteris on the world-scene, Stephen Scheckler, a professor of biology and geological sciences at Virginia Polytechnic Institute, says, "When [Archaeopteris] appears, it very quickly became the dominant tree all over the Earth. On all of the land areas that were habitable, they all had this tree". For the heavy metal band see Soil (band) Soil is the layer of minerals and organic matter, in thickness from centimetres to a metre or more, on the land surface. ... For the Second World War frigate class, see River class frigate The Murray River in Australia A waterfall on the Ova da Fedoz, Switzerland A river is a large natural waterway. ... Flood Plain along Lynches River Johnsonville, South Carolina Showing high water mark on tupelo and cypress trees In geography, a flood plain is a plain formed of sediment, typically dropped by a river. ... This article or section should include material from Virginia Bioinformatics Institute. ...

Scheckler goes on to say, "Its litter fed the streams and was a major factor in the evolution of freshwater fishes, whose numbers and varieties exploded in that time, and influenced the evolution of other marine ecosystems. It was the first plant to produce an extensive root system, so had a profound impact on soil chemistry. And once these ecosystem changes happened, they were changed for all time. It was a one-time thing" (sciencedaily.com).

Looking roughly like a top-heavy Christmas tree, Archaeopteris may have played a part in the transformation of Earth’s climate during the Devonian before becoming extinct within a short period of time at the beginning of the Carboniferous period. A Christmas tree in a German home One of the most popular traditions associated with the celebration of Christmas, the Christmas tree is normally an evergreen conifer tree that is brought in the house or used in the open, and is decorated with Christmas lights and colourful ornaments during the... Map of the climate of the Earth The climate (ancient Greek: κλίμα) is the weather averaged over a long period of time. ...

Relationship to conifers

Because Archaeopteris reproduced by releasing spores rather than by producing seeds, paleobotanists suspect that modern trees come from a sibling line of plants they call the "progymnosperms". Archaeopteris is more like an ancient cousin than a direct ancestor. Still, many sources list it as a progymnosperm.

Discovery and classification

Archaeopteris was originally classified as a fern, and it remained classified so for over 100 years. In 1911, Russian paleontologist Mikhail Dimitrievich Zalessky described a new type of petrified wood from the Donetz Basin in Russia. He called the wood Callixylon, though he did not find any structures other than the trunk. The similarity to conifer wood was recognized. It was also noted that ferns of the genus Archaeopteris were often found associated with fossils of Callixylon. A database query syntax error has occurred. ... The Russian Federation (Russian: Росси́йская Федера́ция, transliteration: Rossiyskaya Federatsiya or Rossijskaja Federacija), or Russia (Russian: Росси́я, transliteration: Rossiya or Rossija), is a country that stretches over a vast expanse of eastern Europe and northern Asia. ... Petrified log at the Petrified Forest National Park Petrified wood is a type of fossil, in which the tissues of a dead plant are replaced with minerals (most often a silicate, like quartz). ... The Russian Federation (Russian: Росси́йская Федера́ция, transliteration: Rossiyskaya Federatsiya or Rossijskaja Federacija), or Russia (Russian: Росси́я, transliteration: Rossiya or Rossija), is a country that stretches over a vast expanse of eastern Europe and northern Asia. ... FOSSIL is a standard for allowing serial communication for telecommunications programs under DOS. FOSSIL stands for Fido Opus SEAdog Standard Interface Layer and was made by a group of Fidonet sysops to make their software work on different machines. ...

In the 1960’s, paleontologist Charles B. Beck was able to demonstrate that the fossil wood known as Callixylon and the leaves known as Archaeopteris were actually part of the same plant. It was a plant with a mixture of characteristics not seen in any living plant, a link between true gymnosperms and ferns. Gymnosperms are seed-bearing, vascular plants. ...

The genus Archaeopteris is placed in the order Archaeopteridales and family Archaeopteridaceae. The name is similar to that of the first known feathered bird, Archaeopteryx, but in this case refers to the feather-like nature of the plant's fronds. Binomial name Archaeopteryx lithographica Meyer, 1861 Archaeopteryx lithographica is widely accepted as the earliest and most primitive known bird. ...

See also

• Glossopteris
• Calamites

Glossopteris (Greek glossa, meaning tongue, because the leaves were tongue-shaped) is the largest and best-known genus of the extinct order of seed ferns known as Glossopteridales. ...

References

• Earliest Modern Tree Lived 360-345 Million Years Ago, from Sciencedaily.com (http://www.sciencedaily.com/releases/1999/04/990422060147.htm)
• History of Paleozoic Forests: the Early Forests and the Progymnosperms (http://www.biologie.uni-hamburg.de/b-online/kerp/seite4.html)
• Consequences of Rapid Expansion of Late Devonian Forests, by Stephen E. Scheckler (http://gsa.confex.com/gsa/2003AM/finalprogram/abstract_65680.htm)
• Walker, Cyril and Ward, David. Fossils. Smithsonian Handbooks. Dorling Kindersley, Inc. New York, NY (2002).
• Mayr, Helmut. A Guide to Fossils. Princeton University Press, Princeton, NJ (1992).
• Introduction to the Progymnosperms (http://www.ucmp.berkeley.edu/seedplants/progymnosperms.html)
• Davis, Paul and Kenrick, Paul; Fossil Plants. Smithsonian Books (in association with the Natural History Museum of London), Washington, D.C. (2004). ISBN 1588341569