New genus of homostiid arthrodire contributes to the revision of placoderm diversity in the Early Devonian of the Prague Basin

2020 ◽  
Vol 44 (3) ◽  
pp. 397-410
Author(s):  
Valéria Vaškaninová
1999 ◽  
Vol 73 (5) ◽  
pp. 850-859 ◽  
Author(s):  
A. J. Boucot ◽  
L. R. M. Cocks ◽  
P. R. Racheboeuf

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.


2021 ◽  
pp. 1-15
Author(s):  
Michał Zatoń ◽  
Mingxi Hu ◽  
Mercedes di Pasquo ◽  
Paul M. Myrow

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


1991 ◽  
Vol 82 (4) ◽  
pp. 324-332 ◽  
Author(s):  
A. G. Lyon ◽  
Dianne Edwards

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.


2020 ◽  
Vol 94 (4) ◽  
pp. 758-772
Author(s):  
David K. Elliott ◽  
Linda S. Lassiter ◽  
Kathryn E. Geyer

AbstractThis report documents the last pteraspids, (armored, jawless members of the Heterostraci), which are otherwise only known from the Early Devonian of the Old Red Sandstone Continent. Tuberculate pteraspid heterostracans are described from the Middle Devonian beds of two formations in western North America. The late Givetian Yahatinda Formation of Alberta and British Columbia consists of channels cut into lower Paleozoic rocks and represents deposition in marine to littoral environments. Clavulaspis finis (Elliott et al., 2000a) new combination is redescribed from additional material from the Yahatinda Formation and reassigned to the new genus Clavulaspis because the original genus name is invalid. The Eifelian Spring Mountain beds of Idaho consist of a large channel that represents a clastic-dominated estuarine environment. It contains Scutellaspis wilsoni new genus new species, and the previously described species from the Spring Mountain beds is redescribed and reassigned to Ecphymaspis new genus, which was prompted by new material and a review of the validity of the original genus name. Phylogenetic analysis shows that these three new taxa form part of the derived clade Protaspididae.UUID: http://zoobank.org/9cf09b21-cec1-4ce4-bc2b-658d0b515e10


2016 ◽  
Vol 90 (6) ◽  
pp. 1212-1224
Author(s):  
David K. Elliott

AbstractThree new species of the new genus Phyllonaspis are described from Early Devonian localities in the western United States. Phyllonaspis laevis, P. serratus, and P. taphensis are broad, flattened cyathaspids with lateral brims and fine dermal ornament, that show a close relationship to the cyathaspids Boothiaspis and Alainaspis from the late Silurian and Early Devonian of the Canadian Arctic. These taxa are here accommodated within the new subfamily Boothiaspidinae within the family Cyathaspididae. This relationship supports previous evidence of faunal connection between these two areas and indicates dispersal around the Old Red Sandstone Continent from a center in the Canadian Arctic. Isolated oral plates allow a reconstruction of the oral cover and increase our knowledge of the range of oral structures in this family.


Fossil Record ◽  
2001 ◽  
Vol 4 (1) ◽  
pp. 71-82 ◽  
Author(s):  
D. Weyer

<i>Muenstraia</i> n. gen. ist eine der ältesten ahermatypischen Rugosa (Subordo Cyathaxoniina) und umfasst neben der Typusart <i>Muenstraia franconica</i> n. sp. (Ludlovium, Elbersreuther Orthoceratitenkalk, Frankenwald) drei weitere Arten: <i>Muenstraia squarrosa</i> (Sutherland, 1965) (unteres Ludlovium, Henryhouse-Formation, Oklahoma), <i>Muenstraia</i> sp. (oberes Lochkovium, Yukon-Gebiet), <i>Muenstraia thuringica</i> n. sp. (Pragium, Thüringisches Schiefergebirge und Tafilalt). Die Gattung kann von dem isolierten, nur aus Xinjiang bekannten Protozaphrentis Yü, 1957 des hohen Mittelordoviz abgeleitet werden; wichtige Deszendenten im Ludlovian sind <i>Laccophyllum</i> Simpson, 1900 und Sutherlandinia Weyer, 1972. <br><br> Der Bauplan entspricht dem seit Schindewolf (1931) traditionellen Konzept der Gattung <i>Petraia</i> Münster, 1839, die aber nach Revision (Weyer 2000) ihrer wahren Typusart <i>Petraia decussata</i> Münster, 1839 aus dem oberen Famennium einer anderen Entwicklungsreihe angehört (Neaxoninae Hill, 1981, jetzt Petraiidae Koninck, 1872). Für die dadurch namenlos gewordene Familia "Petraiidae" (etwa sensu Hill 1981) werden die bisher als Synonym ruhenden Protozaphrentidae Ivanovskiy, 1959 verfügbar, denen noch <i>Duncanella</i> Nicholson, 1874 sowie die Sutherlandiniinae Weyer, 1972 und die Ditoecholasmatinae Sutherland, 1965 zugeordnet sind. <br><br> Muenstraia, a new genus of Rugosa (Anthozoa) from the Late Silurian and Early Devonian <br><br> The new taxon, one of the most ancient members of the ahermatypic suborder Cyathaxoniina, includes the type species <i>Muenstraia franconica</i> n. sp. (Ludlovian, Elbersreuth <i>Orthoceratites</i>-Limestone Formation. Upper Franconia, Germany) and three further species: <i>Muenstraia squarrosa</i> (Sutherland, 1965) (lower Ludlovian, Henryhouse Formation, Oklahoma, USA), <i>Muenstraia</i> sp. (upper Lochkovian, Yukon Territories, Canada). <i>Muenstraia thuringica</i> n. sp. (middle/upper Pragian, Tentaculitid Limestone Formation, Thuringian Mountains, Germany, and middle Pragian, Tafilalt, Morocco). The genus descends from the isolated Upper Middle Ordovician <i>Protozaphrentis</i> Yü, 1957, only known from Xinjiang in China; it is the ancestor of two new phylogenetic lines starting in the Ludlovian with <i>Laccophyllum</i> Simpson, 1900, and <i>Sutherlandinia</i> Weyer, 1972. <br><br> Morphology and diagnosis are identical with the (since Schindewolf 1931) traditional definition of the genus <i>Petraia</i> Münster, 1839, which represents according to a revision of its real and Upper Famennian type species <i>Petraia</i> <i>decussata</i> Münster, 1839 (Weyer 2000) another phylogenetic line (Neaxoninae Hill, 1981, now Petraiidae Koninck, 1872). Therefore, the valid name of the family "Petraiidae" (sensu Hill 1981) becomes Protozaphrentidae Ivanovskiy, 1959, which comprise also <i>Duncanella</i> Nicholson, 1874, and both the Sutherlandiniinae Weyer, 1972 and Ditoecholasmatinae Sutherland, 1965. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.20010040106" target="_blank">10.1002/mmng.20010040106</a>


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