Margaretbarromyces
Encyclopedia
Margaretbarromyces is an extinct monotypic
genus
of pleosporale
fungus
of uncertain family placement. At present it contains the single species
Margaretbarromyces dictyosporus.
The genus is solely known from the Eocene
aged, Appian Way deposits on Vancouver Island
. Margaretbarromyces is one of only three known fossil fungus species found on Vancouver Island and the most recent to be described from the Appian Way strata. The agaricomycete Quatsinoporites cranhamii
was described from a Cretaceous
fossil and Appianoporites vancouverensis
, from the same deposits as Margaretbarromyces were jointly described in a 2004 research paper.
, a complete ascoma like fungus fruiting body. The specimen, AW 400 Htop 0-12, is currently residing in the paleobotanical
collections housed by the University of Alberta
, Edmonton, Alberta, Canada. The specimen was collected south of the Campbell River
on the eastern shore of Vancouver Island
, British Columbia
, Canada. The fungus specimen was preserved in a calcareous nodule
recovered from a silty mudstone matrix. The nodules formed in a shallow marine environment along with abundant plant material.
It was first studied by a group of researchers consisting of Randal Mindell, Randolph Currah & Ruth Stockey, from the University of Alberta
and Graham Beard of the Vancouver Island Paleontology Museum, Qualicum Beach, British Columbia. Mindell and colleagues published their 2007 type description in the journal Mycological Research
volume 111. The generic epithet Margaretbarromyces was coined from a recognition of Margaret Barr for here research on the loculoascomycete fungi
and "myces" to reflect that it is a fungus. The specific epithet "dictyosporus" was coined to reflect the condition of the ascospores.
When first described Margaretbarromyces dictyosporus was the most recent fungus species to be described from Vancouver Island. Cryptodidymosphaerites princetonensis and Palaeoserenomyces allenbyensis were the first fossil fungi to be described from British Columbia, known only from the Early Eocene Allenby Formation near Princeton, B.C.
. Quatsinoporites cranhamii
a Cretaceous
age agaricomycete from the western coast of Vancouver Island and Appianoporites vancouverensis
, also from the Appian Way site, were described in the same 2004 paper. With is publication three years later, Margaretbarromyces was the fifth fossil fungus described from British Columbia.
in diameter by 420 μm in height in bark of an unidentified seed plant, which was transported by water before preservation in a calcareous nodule. The ascoma is composed of high branching and complex anastomosed hyphae. The interior chamber of the ascoma, filled with calcite
, preserves several asci
and a number of ascospores. Though the asci are faint the groupings of ascospores are well preserved showing the placement of the asci to be basal. Each ascospore is between 55-90μm and dictyosporous. The specimen was studied by cutting the calcareous nodule into slices with a rock saw and using the cellulose acetate peel technique to create slides that were examined under stereo microscope.
With its distinct basal asci placement and dictyosporous ascospores, combined with the ascoma growing within existing tissues, Margaretbarromyces distinct from known genera. Though several other fungal orders have some similar characters the particular grouping found in Margaretbarromyces is closest to members of the Pleosporales
. Placement at the family level is uncertain due to the fluctuating nature of the family descriptions.
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of pleosporale
Pleosporales
The Pleosporales is the largest order in the fungal class Dothideomycetes. By some estimates it contains 23 families, 332 genera and more than 4700 species. The majority of species are saprobes on decaying plant material in fresh water, marine, or terrestrial environments, but several species are...
fungus
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
of uncertain family placement. At present it contains the single species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
Margaretbarromyces dictyosporus.
The genus is solely known from the Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
aged, Appian Way deposits on Vancouver Island
Vancouver Island
Vancouver Island is a large island in British Columbia, Canada. It is one of several North American locations named after George Vancouver, the British Royal Navy officer who explored the Pacific Northwest coast of North America between 1791 and 1794...
. Margaretbarromyces is one of only three known fossil fungus species found on Vancouver Island and the most recent to be described from the Appian Way strata. The agaricomycete Quatsinoporites cranhamii
Quatsinoporites
Quatsinoporites is an extinct monotypic genus of agaricomycet fungus in the Agaricomycetes family Hymenochaetaceae. At present it contains the single species Quatsinoporites cranhamii....
was described from a Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
fossil and Appianoporites vancouverensis
Appianoporites
Appianoporites is an extinct monotypic genus of fungus in the Agaricomycetes family Hymenochaetaceae. At present it contains the single species Appianoporites vancouverensis....
, from the same deposits as Margaretbarromyces were jointly described in a 2004 research paper.
History and classification
The genus Margaretbarromyces is known only from the single holotypeHolotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
, a complete ascoma like fungus fruiting body. The specimen, AW 400 Htop 0-12, is currently residing in the paleobotanical
Paleobotany
Paleobotany, also spelled as palaeobotany , is the branch of paleontology or paleobiology dealing with the recovery and identification of plant remains from geological contexts, and their use for the biological reconstruction of past environments , and both the evolutionary history of plants, with a...
collections housed by the University of Alberta
University of Alberta
The University of Alberta is a public research university located in Edmonton, Alberta, Canada. Founded in 1908 by Alexander Cameron Rutherford, the first premier of Alberta and Henry Marshall Tory, its first president, it is widely recognized as one of the best universities in Canada...
, Edmonton, Alberta, Canada. The specimen was collected south of the Campbell River
Campbell River (Vancouver Island)
The Campbell River is a river on Vancouver Island, British Columbia, Canada, draining into Discovery Passage at the northwest end of the Strait of Georgia, at the City of Campbell River, which is named for the river. The Kwak'wala name for the river, or for the village near its mouth The Campbell...
on the eastern shore of Vancouver Island
Vancouver Island
Vancouver Island is a large island in British Columbia, Canada. It is one of several North American locations named after George Vancouver, the British Royal Navy officer who explored the Pacific Northwest coast of North America between 1791 and 1794...
, British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
, Canada. The fungus specimen was preserved in a calcareous nodule
Calcareous
Calcareous is an adjective meaning mostly or partly composed of calcium carbonate, in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines.-In zoology:...
recovered from a silty mudstone matrix. The nodules formed in a shallow marine environment along with abundant plant material.
It was first studied by a group of researchers consisting of Randal Mindell, Randolph Currah & Ruth Stockey, from the University of Alberta
University of Alberta
The University of Alberta is a public research university located in Edmonton, Alberta, Canada. Founded in 1908 by Alexander Cameron Rutherford, the first premier of Alberta and Henry Marshall Tory, its first president, it is widely recognized as one of the best universities in Canada...
and Graham Beard of the Vancouver Island Paleontology Museum, Qualicum Beach, British Columbia. Mindell and colleagues published their 2007 type description in the journal Mycological Research
Mycological Research
Fungal Biology is a scientific journal that publishes peer-reviewed papers on all aspects of basic and applied research of the fungi, including lichens, yeasts, oomycetes, and slime moulds.- History :...
volume 111. The generic epithet Margaretbarromyces was coined from a recognition of Margaret Barr for here research on the loculoascomycete fungi
Pezizomycotina
Pezizomycotina contains the filamentous ascomycetes and is a subphylum of the Ascomycota . It is more or less synonymous with the older taxon Euascomycota...
and "myces" to reflect that it is a fungus. The specific epithet "dictyosporus" was coined to reflect the condition of the ascospores.
When first described Margaretbarromyces dictyosporus was the most recent fungus species to be described from Vancouver Island. Cryptodidymosphaerites princetonensis and Palaeoserenomyces allenbyensis were the first fossil fungi to be described from British Columbia, known only from the Early Eocene Allenby Formation near Princeton, B.C.
Princeton, British Columbia
Princeton is a small town in the Similkameen region of southern British Columbia, Canada. It lies just east of the Cascade Mountains, which continue south into Washington, Oregon and California. The Tulameen and Similkameen Rivers converge here...
. Quatsinoporites cranhamii
Quatsinoporites
Quatsinoporites is an extinct monotypic genus of agaricomycet fungus in the Agaricomycetes family Hymenochaetaceae. At present it contains the single species Quatsinoporites cranhamii....
a Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
age agaricomycete from the western coast of Vancouver Island and Appianoporites vancouverensis
Appianoporites
Appianoporites is an extinct monotypic genus of fungus in the Agaricomycetes family Hymenochaetaceae. At present it contains the single species Appianoporites vancouverensis....
, also from the Appian Way site, were described in the same 2004 paper. With is publication three years later, Margaretbarromyces was the fifth fossil fungus described from British Columbia.
Description
The holotype of Margaretbarromyces is a lone ascoma like fruiting body 390 μmMicrometer
A micrometer , sometimes known as a micrometer screw gauge, is a device incorporating a calibrated screw used widely for precise measurement of small distances in mechanical engineering and machining as well as most mechanical trades, along with other metrological instruments such as dial, vernier,...
in diameter by 420 μm in height in bark of an unidentified seed plant, which was transported by water before preservation in a calcareous nodule. The ascoma is composed of high branching and complex anastomosed hyphae. The interior chamber of the ascoma, filled with calcite
Calcite
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate . The other polymorphs are the minerals aragonite and vaterite. Aragonite will change to calcite at 380-470°C, and vaterite is even less stable.-Properties:...
, preserves several asci
Ascus
An ascus is the sexual spore-bearing cell produced in ascomycete fungi. On average, asci normally contain eight ascospores, produced by a meiotic cell division followed, in most species, by a mitotic cell division. However, asci in some genera or species can number one , two, four, or multiples...
and a number of ascospores. Though the asci are faint the groupings of ascospores are well preserved showing the placement of the asci to be basal. Each ascospore is between 55-90μm and dictyosporous. The specimen was studied by cutting the calcareous nodule into slices with a rock saw and using the cellulose acetate peel technique to create slides that were examined under stereo microscope.
With its distinct basal asci placement and dictyosporous ascospores, combined with the ascoma growing within existing tissues, Margaretbarromyces distinct from known genera. Though several other fungal orders have some similar characters the particular grouping found in Margaretbarromyces is closest to members of the Pleosporales
Pleosporales
The Pleosporales is the largest order in the fungal class Dothideomycetes. By some estimates it contains 23 families, 332 genera and more than 4700 species. The majority of species are saprobes on decaying plant material in fresh water, marine, or terrestrial environments, but several species are...
. Placement at the family level is uncertain due to the fluctuating nature of the family descriptions.