The first zosterophyll from the Lower Devonian Rhynie Chert, Aberdeenshire

1991 ◽  
Vol 82 (4) ◽  
pp. 324-332 ◽  
Author(s):  
A. G. Lyon ◽  
Dianne Edwards
Keyword(s):  
Lower Devonian ◽  
New Genus ◽  
New Genus And Species ◽  
Early Devonian ◽  
Precise Positioning ◽  
Cortical Zone ◽  
Lack Of Information ◽  
Rhynie Chert

ABSTRACTFragmentary remains of a vascular sporophyte from the Rhynie Chert are described as a new genus and species, Trichopherophyton teuchansii. The plant, which is characterised by the possession of unicellular spinous hairs, exarch xylem and laterally attached, marginally dehiscent sporangia, is assigned to the Zosterophyllophytina, but lack of information on the arrangement of sporangia prevents its more precise positioning within the subdivision. Unusual features include the combination of circinate tips to axes with almost terete xylem strands, and the lack of a thick-walled outer cortical zone. Associated axes, lacking spinous hairs, but having papillate or rhizoid-like epidermal emergences, are interpreted as likely rhizomes of Trichopherophyton. Features, such as unicellular spinous hairs, rhizoid-like emergences, circinate tipsand parenchymatous cortex are considered in relation to the functioning and growth of aplant inhabiting an early Devonian wetland.

A new vascular plant from the Lower Devonian Windyfield chert, Rhynie, NE Scotland

1999 ◽  
Vol 90 (4) ◽  
pp. 331-349 ◽  
Author(s):  
Clare L. Powell ◽  
Dianne Edwards ◽  
Nigel H. Trewin
Keyword(s):  
Lower Devonian ◽  
New Genus ◽  
Vascular Plant ◽  
New Taxon ◽  
New Genus And Species ◽  
Rhynie Chert ◽  
Microbial Film

AbstractTwo plants are described from fragmentary remains preserved in the Windyfield chert, situated c. 600 m from the classic Rhynie chert locality. Both are sometimes coated by a microbial film. The larger, fertile axes are placed in the new genus and species Ventarura lyonii. They possess a distinctive, sclerenchymatous middle cortex and terete xylem, and marginally dehiscent, lateral sporangia. The new taxon is similar to the Rhynie zosterophyll Trichopherophyton teuchansii, but is placed in a new genus on sporangial differences. Associated smaller axes with unicellular epidermal outgrowths lack the middle cortex of the larger axes and often have medullated protosteles. They are interpreted as subterranean rhizomes and probably belong to the new fertile taxon, but organic continuity between the two has not been demonstrated.

Two new cirroidean genera (Vetigastropoda, Archaeogastropoda) from the Emsian (Late Early Devonian) of Alaska with notes on the early phylogeny of Cirroidea

1998 ◽  
Vol 72 (2) ◽  
pp. 265-273 ◽  
Author(s):  
Jiří Frýda ◽  
Robert B. Blodgett
Keyword(s):  
New Species ◽  
Lower Devonian ◽  
New Genus ◽  
New Genus And Species ◽  
Early Devonian ◽  
West Central ◽  
The Family ◽  
First Time ◽  
Stratigraphic Range

Two new cirroidean gastropod genera, Alaskiella (family Porcelliidae) and Alaskacirrus (family Cirridae), from the Emsian (late Early Devonian) of west-central Alaska (Medfra B-4 quadrangle) are described. The shell of Alaskiella medfraensis new genus and species exhibits inclined heterostrophic coiling. This shell character is known among other members of the subclass Archaeogastropoda, but is recorded for the first time within members of the superfamily Cirroidea. Inclined heterostrophic coiling of the shell was probably developed independently in several different groups of the subclass Archaeogastropoda. The new genus Alaskacirrus, represented by Alaskacirrus bandeli new species, is the oldest and only known Paleozoic member of the family Cirridae. This suggests that the family Cirridae was separated from the family Porcelliidae since at least Early Devonian time and that it most probably developed from the subfamily Agnesiinae of the family Porcelliidae. Thus, the stratigraphic range of the family Cirridae is at least from Lower Devonian to Cretaceous, an interval of about 350 million years.

Early Devonian brachiopods from Satun Province, southern Thailand

1999 ◽  
Vol 73 (5) ◽  
pp. 850-859 ◽  
Author(s):  
A. J. Boucot ◽  
L. R. M. Cocks ◽  
P. R. Racheboeuf
Keyword(s):  
New Species ◽  
New Genus ◽  
New Genus And Species ◽  
Benthic Assemblages ◽  
Early Devonian ◽  
Old World ◽  
Southern Thailand ◽  
Biogeographical Region

Twelve brachiopod taxa are described from the Early Devonian (probable early Emsian) Pa Samed Formation of southern Thailand, including the new genus and species Quasiprosserella samedensis (Ambocoeliidae?) and the new species Plectodonta forteyi, Caplinoplia thailandensis, and Clorinda wongwanichi. They are the first undoubted Devonian brachiopods from Thailand. They represent the deeper-water Benthic Assemblages BA4-5, and, although clearly indicative of the Old World Realm, cannot be assigned to a particular biogeographical region. A new undescribed fauna from the contemporary Zebingyi Formation of Burma (Myanmar) is also noted.

Adaptive function and phylogenetic significance of novel skeletal features of a new Devonian microconchid tubeworm (Tentaculita) from Wyoming, USA

2021 ◽  
pp. 1-15
Author(s):  
Michał Zatoń ◽  
Mingxi Hu ◽  
Mercedes di Pasquo ◽  
Paul M. Myrow
Keyword(s):  
Middle Devonian ◽  
New Genus ◽  
Adaptive Strategy ◽  
Phylogenetic Significance ◽  
New Genus And Species ◽  
Adaptive Function ◽  
Faunal Assemblage ◽  
Early Devonian ◽  
Narrow Channels ◽  
Algal Thalli

Abstract A new genus and species of microconchid tubeworm, Aculeiconchus sandbergi n. gen. n. sp., is described from the Givetian (Devonian) Maywood Formation of Cottonwood Canyon, Wyoming, USA. It possesses unique hollow spines of various lengths on the tube underside, a position previously undocumented for these fossils. Like some cyclostome bryozoans possessing basal tubular extensions, the basal spines of Aculeiconchus n. gen. were presumably also used for fixation to flexible substrata, e.g., algal thalli, which is a previously undocumented adaptive strategy in microconchids. Together with other skeletal features, such basal spines could suggest that ‘lophophorate’ microconchids, unlike the other tentaculitoids, might be phylogenetically not as distant from bryozoans as previously thought. The Maywood Formation, which contains a few-millimeters thick, monospecific shell accumulation of the microconchids described herein, records deposition in an estuarine brackish setting within narrow channels that were cut into underlying strata. The microconchids were opportunistic taxa that repeatedly colonized these salinity-stressed estuarine channels, leading to a series of adaptive innovations, including colonization of plant stems during the Early Devonian (Beartooth Butte Formation) and possibly flexible, soft-algal substrata during the Middle Devonian (Maywood Formation, this study). Tectonic quiescence during the Early and Middle Devonian indicates that erosion and subsequent deposition of the Maywood and the underlying Beartooth Butte Formation channels were responses to major eustatic events. Over a span of nearly 30 Myr, channels were cut successively during lowstand conditions and a distinctive faunal assemblage with microconchids tracked marine transgressions into the channels. UUID: http://zoobank.org/394c8b32-d5e7-411e-8e56-6fb9f55bbb8a

IV.—On the Fragmentary Remains of an Organism Referable to the Nematophytales, from the Rhynie Chert, Nematoplexus rhyniensis gen. et sp. nov.

1962 ◽  
Vol 65 (4) ◽  
pp. 79-87 ◽  
Author(s):  
A. G. Lyon
Keyword(s):  
New Genus ◽  
New Genus And Species ◽  
Tubular Cells ◽  
Uniformly Smooth ◽  
Rhynie Chert

SynopsisIncomplete, but structurally preserved remains of an organism referable to the Nematophytales Lang, are described from the Rhynie Chert as a new genus and species. The fossil is composed of a plexus of non-septate tubular cells of two types—the smaller having uniformly smooth walls, the larger, walls with conspicuous spiral thickenings. Branching of both types is localized in areas referred to as branch-knots. Comparison is made with other members of the Nematophytales which have been shown to possess differentially thickened tubes.

Catenalis digitata, gen. et sp.nov., a plant from the Lower Devonian (Siegenian) of Yunnan, China

1991 ◽  
Vol 69 (4) ◽  
pp. 873-882 ◽  
Author(s):  
Hao Shougang ◽  
Charles B. Beck
Keyword(s):  
Key Words ◽  
Vascular Plants ◽  
Major Part ◽  
Lower Devonian ◽  
New Genus ◽  
Vascular Plant ◽  
Morphological Differentiation ◽  
Distal Margin ◽  
New Genus And Species

A new genus and species, Catenalis digitata, is described from two localities of the Posonchong Formation of Siegenian age in the Wenshan district of Yunnan. This small, dichotomously branched plant exhibits morphological differentiation into a vegetative region that comprises the major part of the plant and terminal fertile regions. The fertile regions consist of fan-shaped clusters of terminal branchlets that bear uniseriate sporangia on only one side. Many sporangia have a crescent-shaped dehiscence slit near the distal margin. Some terminal branchlets in fertile regions lack sporangia, but the positions from which they have apparently been lost are conspicuous as elliptical regions. In these segments a dark, carbonaceous strand is apparent in a groove along the midplane. A few tracheid-like fragments have been macerated from a segment of carbonized axis suggesting that Catenalis might have been a vascular plant, but because of a lack of detailed information on the components of these strands we cannot conclude with certainty that they were typical vascular plant tracheids. Because of a morphology intermediate between that of certain fucalean algae and typical land vascular plants, we suggest that Catenalis might represent a group ancestral to vascular plants or a new group of primitive vascular plants of algal derivation. Key words: Catenalis digitata, alga-like, dichotomous, uniseriate sporangia, Siegenian, Yunnan.

scholarly journals New dalmanitid trilobite taxa from the Lower Devonian of Argentina: comments on spinosity in endemic taxa from southern high paleolatitudes

2022 ◽  
Author(s):  
Enrique A. RANDOLFE ◽  
Juan José RUSTÁN ◽  
Arnaud BIGNON
Keyword(s):  
Lower Devonian ◽  
New Genus ◽  
Marine Ecosystems ◽  
Predation Pressure ◽  
New Genus And Species

Three new Lower Devonian dalmanitid trilobite taxa are recognized from the Talacasto Formation in the Precordillera Basin, Argentina, which includes two monospecific genera (Ivanites leonorae n. gen., n. sp. and Aguaditaspis mediaspina n. gen., n. sp.), and one additional new genus and species left in open nomenclature. These taxa combine characters of the subfamilies Dalmanitinae Vogdes, 1890 and Synphoriinae Delo, 1935, challenging their taxonomic distinction. Forty percent of the dalmanitids from high paleolatitudinal basins from southwestern Gondwana (Malvinokaffric) exhibit non-homologous dorsal spinosity. Aguaditaspis mediaspina n. gen., n. sp. shares similar spines with Trypaulites calypso (Hall, 1861). The unnamed new genus resembles the spinosity of endemic Malvinokaffric dalmanitids, like Dalmanitoides Delo, 1935 and Fenestraspis Braniša & Vaněk, 1973. Considered defensive, the recorded spinosity along with putative sublethal-attack marks, suggest higher predation pressure than previously thought at high paleolatitudes. This evidence is in accordance with some hypothesis on rising predation pressure in the mid-Paleozoic marine ecosystems.

New and revised Lower Devonian Rugosa from Western North America and Tasmania

1998 ◽  
Vol 72 (2) ◽  
pp. 224-245 ◽  
Author(s):  
A.E.H. Pedder
Keyword(s):  
North America ◽  
Type Species ◽  
Lower Devonian ◽  
New Genus ◽  
Yukon Territory ◽  
Western North America ◽  
Family Status ◽  
New Genus And Species ◽  
New Material

Anactolasma yukonanum new genus and species is described from the Pragian of Yukon Territory and is assigned to the Anactolasmatinae, a new subfamily of the Mucophyllidae Hill. Adult stages of Anactolasma resemble gerontic stages of Kobeha Merriam, although the genera have distinct ontogenies. Kobeha is revised on the basis of new material of its type species K. walcotti Merriam. The Papiliophyllinae Stumm are promoted to family status. Kobeha ketophylloides Merriam, from the Pragian of Nevada, and Endophyllum banksi Jell and Hill, from the Pragian of Tasmania, are restudied using new topotypic and other material. A new endophyllid genus named Murphyphyllum is erected for them, with E. banksi as type species. Asarcophyllum ramosum new genus and species, from the Emsian of Nevada, is made type species of a new cyathophyllid genus. Spongophyllum nevadense Stumm and S. expansum Stumm, both also from the Emsian of Nevada, are placed in the new genus, as is Asarcophyllum corona new genus and species, from the Emsian of Yukon Territory. Biostratigraphic settings, with emphasis on associated corals, brachiopods and conodonts, are given for the new and revised genera and species.

Early Devonian gastropods from Zhusilenghaierhan region, western inner Mongolia, China

2003 ◽  
Vol 77 (1) ◽  
pp. 31-43 ◽  
Author(s):  
Pan Hua-Zhang ◽  
Alex G. Cook
Keyword(s):  
New Species ◽  
Inner Mongolia ◽  
New Genus ◽  
New Genus And Species ◽  
Early Devonian ◽  
Genus Level ◽  
Eastern Australia

Early Devonian (Emsian) gastropods from the Zhusileng Formation of Zhusilenghaierhan Region, West Inner Mongolia, China, consisting of 18 taxa, including Neimongolidiscus circumumbilicus new genus and species, Pseudopharkidonotus sinensis new genus and species, Nodulospira danmianshanensis new genus and species, Zhusilengospira turbiniformis new genus and species, Zhusilengospira compactum new genus and species, Taemasotrochus nodosa new species, and Scalaetrochus sinensis new species. Endemic forms dominate the fauna, which shows some genus level affinities with Eastern Australia, the Kitikami Mountains of Japan. The fauna does feature small numbers of cosmopolitan taxa.

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