PALAEOBOTANICAL RESEARCH GROUP
UNIVERSITY  MÜNSTER


HISTORY  OF  PALAEOZOIC  FORESTS
FOSSIL  AND  EXTANT SPHENOPHYTES


Sphenophytes or Articulates are a group of spore plants with articulated axes and leaves standing in whorls. Fructifications typically consist of strobili. Sphenophytes were widespread in the Carboniferous and Early Permian. Two major groups can be distinguished, the Calamitales and the Sphenophyllales. The calamites were rhizome-borne trees with secondary growth which could reach a height of up to 20 m. Most species are indicative for humid to wet environments. They often occurred in monotypic stands along the shorelines of lakes and rivers, probably comparable to modern reed vegetations. The name Calamites was originally given to pith casts of the hollow stems, but is now also used for the whole plant. Annularia and Asterophyllites are two types of calamite foliage. The sphenophylls were herb-like plants with typical wedge-shaped leaves arranged in whorls. The only living sphenophyte is the modern Equisetum or horsetail.


Taxon / Subject
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Calamites is a genus for the stems of fossil giant horsetails.  The genus has been established for the pith casts, the natural infillings of the hollow central parts of the stem.  The stems are articulated and have nodes and internodes.  Calamites shows characteristic ribs which normally alternate at the nodes.  The pithcasts only give an idea about the diameter of the internal cavity of the stem, not about the diameter of the stem itself !  Outer stem surfaces are rare. The generic name is also used for permineralized stems, e.g. in coal balls. Many species have been described.  However, the taxonomy is rather confusing.
Calamites carinatus Plant fossils from the Northen Anthracite Field  
Calamites cistii Plant fossils from the Northen Anthracite Field  
Calamites cistii M. Hieb's Plant Fossils of West Virginia  
Calamites cistii M. Hieb's Plant Fossils of West Virginia   
Calamites cistii  M. Hieb's Plant Fossils of West Virginia  branching axes
Calamites cistii Southern Illinois University Museum  
Calamites cistii Southern Illinois University Museum  
Calamites suckowii M. Hieb's Plant Fossils of West Virginia basal part of aerial shoot; upside down
Calamites  M. Hieb's Plant Fossils of West Virginia outer surface with branch scars
Calamites sp. Mazon Creek Exhibit, Illinois State Museum   
Calamites sp. Paleontologisk Museum, Oslo  
Calamites Collection Jens-Wilhelm Janzen
 
Calamites Kathleen Pigg's "Plant Fossils and Evolution"
 
Calamites R.A. Spicer, The Open University, Milton Keynes  
Calamites Botanical Society of America: Online Image Coll. longitudinal section
Calamites Botanical Society of America: Online Image Coll. as above; high resolution image
Calamites Botanical Society of America: Online Image Coll. cross section
Calamites Botanical Society of America: Online Image Coll. as above; high resolution image
Calamites Botanical Society of America: Online Image Coll. cross section
Calamites Botanical Society of America: Online Image Coll. as above; high resolution image
Calamites Botanical Society of America: Online Image Coll. cross section
Calamites Botanical Society of America: Online Image Coll. as above; high resolution image
Calamites Humboldt State University   
Calamites Univ. California Mus. Paleontology, Berkeley  
Calamites Georgia Perimeter College  
Calamites Virtual Paleobotany, UCL Berkeley  
Calamites Virtual Paleobotany, UCL Berkeley cross section
Calamites Computational Paleontology page  computer graphic
Annularia is a genus for calamitalean foliage. The narrow lancet-like Annularia leaves are placed in whorls, positioned at the nodes. All leaves lie in one plane and the whorls are circular to oval in outline.  Several dozens of species are distinguished, some of them being valuable index fossils.
Annularia radiata M. Hieb's Plant Fossils of West Virginia 
 
Annularia radiata M. Hieb's Plant Fossils of West Virginia   
Annularia radiata Fossils of Nova Scotia  
Annularia radiata Botany Online  
Annularia stellata Fossils of Nova Scotia  
Annularia stellata Humboldt State University  
Annularia asteris M. Hieb's Plant Fossils of West Virginia   
Annularia sp. Mazon Creek Exhibit, Illinois State Museum  
Annularia Collection Jens-Wilhelm Janzen  
Annularia M. Hieb's Plant Fossils of West Virginia   
Annularia sphenophylloides Kathleen Pigg's "Plant Fossils and Evolution"  
Annularia Virtual Paleobotany, UCL Berkeley  
Annularia Georgia Perimeter College  
Annularia Kentucky Paleontological Society  
Annularia Kentucky Paleontological Society  
Annularia Univ. Frankfurt nice branching specimen
Annularia Humboldt State University  
Annularia Univ. California Mus. Paleontology, Berkeley  
Asterophyllites is another type of calamitalean foliage. The narrow needle-shaped leaves are also positioned in whorl inserted at the nodes but all leaves are directed towards the apex of the shoot.  The leaf whorls are laterally compressed. Some of the Asterophyllites species are valuable index fossils.
Asterophyllites equisetiformis Mazon Creek Exhibit, Illinois State Museum  
Asterophyllites charaeformis M. Hieb's Plant Fossils of West Virginia  
Asterophyllites equisiteformis M. Hieb's Plant Fossils of West Virginia  
Asterophyllites equisetiformis Natural History Museum, Maastricht, NL  
Asterophyllites equisetiformis Kathleen Pigg's "Plant Fossils and Evolution"  
Asterophyllites equisetiformis Fossils of Nova Scotia  
Asterophyllites equisetiformis Westphalian D of Zwickau  
Asterophyllites longifolius Westphalian D of Zwickau  
Asterophyllites Collection Jens-Wilhelm Janzen  
Asterophyllites Univ. Pierre et Marie Curie Paris  
Asterophyllites Virtual Paleobotany, UCL Berkeley  
Asterophyllites Botanical Society of America: Online Image Coll.  coal ball material
Asterophyllites Botanical Society of America: Online Image Coll. coal ball material
Calamostachys is a genus that has been defined for one of the fructification types of Calamitaleans.  The stobilus axes are articulated like all the other axial parts of the plant and bear bracts at the nodes.  The sporophylls holding the sporangia are inserted in between on the internodes.  The exact mode of attachment of the sporophylls is often difficult to recognise in compression material.
Calamostachys sp. M. Hieb's Plant Fossils of West Virginia   
Calamostachys M. Hieb's Plant Fossils of West Virginia   
Calamostachys Collection Jens-Wilhelm Janzen  
Calamostachy binneyana Botanical Society of America: Online Image Coll. cross section
Calamostachys binneyana Botanical Society of America: Online Image Coll. as above; high resolution image
Calamostachys binneana Botanical Society of America: Online Image Coll. longitudinal section
Calamostachys binneyana Botanical Society of America: Online Image Coll. as above; high resolution image
Palaeostachya M. Hieb's Plant Fossils of West Virginia   
Strobili Virtual Paleobotany, UCL Berkeley  
Sphenophyllum is a genus of spore plants with articulated axes and wedge-shaped leaves which are positioned in whorls, inserted at the nodes.  Leaf whorls usually hold six leaves.  The genus Sphenophyllum was originally established for leaf compressions but is now also used for permineralised axes.  In crsoss section the axes show a typical triarch xylem with secondary growth.  Sphenophylls were herbaceous plants, at least several species had a scrambling growth habit.  The various Sphenophyllum foliage species are valuable index fossils for the Upper Carboniferous and Lower Permian.
Sphenophyllum angustifolium M. Hieb's Plant Fossils of West Virginia   
Sphenophyllum cuneifolium M. Hieb's Plant Fossils of West Virginia   
Sphenophyllum emarginatum Humboldt State University  
Sphenophyllum emarginatum Humboldt State University  
Sphenophyllum emarginatum Plant fossils from the Northen Anthracite Field  
Sphenophyllum emarginatum
M. Hieb's Plant Fossils of West Virginia   
Sphenophyllum emarginatum Fossils of Nova Scotia  
Sphenophyllum emarginatum Westphalian D of Zwickau  
Sphenophyllum geinitzii Westphalian D of Zwickau  
Sphenophyllum longifolium Westphalian D of Zwickau  
Sphenophyllum majus TU Dresden, Institut dür Geotechnik  
Sphenophyllum majus Fossils of Nova Scotia  
Sphenophyllum geinitzii Westphalian D of Zwickau  
Sphenophyllum M. Hieb's Plant Fossils of West Virginia  
Sphenophyllum M. Hieb's Plant Fossils of West Virginia   
Sphenophyllum M. Hieb's Plant Fossils of West Virginia   
Sphenophyllum Collection Jens-Wilhelm Janzen  
Sphenophyllum Francis Marion University reconstruction; go to Sphenophyllum
Sphenophyllum Plant Biology OSU Lima cross section
Sphenophyllum Kathleen Pigg's "Plant Fossils and Evolution" cross section
Sphenophyllum Univ. California Mus. Paleontology, Berkeley   
Sphenophyllum Virtual Paleobotany, UCL Berkeley  
Sphenophyllum Virtual Paleobotany, UCL   
Sphenophyllum plurifoliatum Botanical Society of America: Online Image Coll. cross section
Sphenophyllum plurifoliatum Botanical Society of America: Online Image Coll. as above; high resolution image
Sphenophyllum Botanical Society of America: Online Image Coll. cross section
Sphenophyllum Botanical Society of America: Online Image Coll. as above; high resolution image
Only a single genus of sphenophytes has survived up the present day, Equisetum.  All species are herbaceous. The following site gives some information on extant sphenophytes.
Modern sphenophytes Univ. California Mus. Paleontology, Berkeley   
 
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Disclaimer

The last check of the list of links was done on 8 December 2002.  The links give the most direct connections to pictures available on the web; in many cases they are from sites that have additional palaeobotanical information.  The above ratings refer to: 
1. Pics: the quality of the specimens, particularly with regard to characteristic features, and to the quality of the pictures. 
2. Info: the additional information provided.
Ratings are of course subjective but should be helpful for finding the fastest way to good pictures on the web. Own pictures are of course not rated. This is up to you! 
Although are checked regularly, some may be outdated due to rapid changes of web addresses.  Suggestions for improvement and hints to other internet resources are most welcome

 

© Forschungsstelle für Paläobotanik, Westfälische Wilhelms-Universität Münster
updated: December  2002