A new post-early Cambrian archaeocyath from Antarctica

1992 ◽  
Vol 129 (4) ◽  
pp. 491-495 ◽  
Author(s):  
Rachel A. Wood ◽  
Kevin R. Evans ◽  
Andrey Yu. Zhuravlev
Keyword(s):  
New Species ◽  
Modular Form ◽  
Early Cambrian ◽  
Middle Cambrian ◽  
Storm Deposit ◽  
Form Part ◽  
A New Species

AbstractA new species of archaeocyath sponge, Dictyocyathus neptunensis, is described from the lower third of the Nelson Limestone of the Neptune Range, Antarctica. Based on the presence of the trilobites Nelsonia schesis and Amphoton oatesi, these strata are interpreted to be mid- to late middle Cambrian in age. D. neptunensis shows a branching, low integration modular form and a very simple skeletal type. Such an organization is predicted from known morphological trends within the early Cambrian Archaeocyatha. Specimens are not in life position, and probably form part of a storm deposit. The absence of Dictyocyathus from latest early Cambrian (Toyonian) strata worldwide suggests a convergent nature for this highly simplified skeletal type in archaeocyaths.

New well-preserved scleritomes of Chancelloriida from early Cambrian Guanshan Biota, eastern Yunnan, China

2018 ◽  
Vol 92 (6) ◽  
pp. 955-971 ◽  
Author(s):  
Jun Zhao ◽  
Guo-Biao Li ◽  
Paul A. Selden
Keyword(s):  
New Species ◽  
Detailed Comparison ◽  
The Body ◽  
Single Element ◽  
Early Cambrian ◽  
Top Down ◽  
Middle Cambrian ◽  
Unusual Form ◽  
Guanshan Biota ◽  
A New Species

AbstractA large number of well-preserved chancelloriid scleritomes from the Guanshan biota, early Cambrian of Yunnan, China, are described as a new species,Allonnia tenuisn. sp., and provide solid evidence for the original appearance of these enigmatic animals, based on specimens compacted laterally and top-down. With the assistance of a flexible integument, chancelloriids, especiallyAllonniafrom early and middle Cambrian, may have had the ability to partially or completely expand and contract the body, which might have played an important role in feeding. A new metazoan with single-element spines,Nidelric gaoloufangensisn. sp., is also described. Preservation and affinity are discussed. Detailed comparison of the morphology of the body and spines of this metazoan indicate that it shares many similarities with chancelloriids, of which it may be an unusual form.UUID:http://zoobank.org/2708d95a-1fae-46fc-afea-9707ae97a4d7

scholarly journals Tarimspirafrom the Cambrian (Series 2, Stage 4) of Laurentia (Greenland): extending the skeletal record of paraconodontid vertebrates

2018 ◽  
Vol 93 (1) ◽  
pp. 115-125
Author(s):  
John S. Peel
Keyword(s):  
New Species ◽  
Type Species ◽  
Weak Acid ◽  
Early Cambrian ◽  
Basal Cavity ◽  
Stage 4 ◽  
First Time ◽  
A New Species ◽  
North Greenland

AbstractPhosphatic sclerites of the problematicTarimspiraYue and Gao, 1992 (Cambrian Series 2) recovered by weak acid maceration of limestones display a unique range of mainly strongly coiled morphologies. They were likely organized into multielement scleritomes, but the nature of these is poorly known; some sclerites may have had a grasping function.Tarimspirasclerites grew by basal accretion in an analogous fashion to younger paraconodonts (Cambrian Series 3–4) but lack a basal cavity. Based on proposed homologies,Tarimspiramay provide an extension of the early vertebrate paraconodont–euconodont clade back into the early Cambrian.Tarimspirais described for the first time from Laurentia (North Greenland), extending its known range from China and Siberia in Cambrian Series 2. In addition to the type species,Tarimspira planaYue and Gao, 1992, the Greenland record ofTarimspiraincludes two morphotypes of a new species,Tarimspira artemi.UUID:http://zoobank.org/c7c536c8-cdaf-49a9-ae1d-77c392f553fc.

Lower Cambrian (Branchian) trilobites and biostratigraphy of the Hanford Brook Formation, southern New Brunswick

2000 ◽  
Vol 74 (5) ◽  
pp. 858-878 ◽  
Author(s):  
Stephen R. Westrop ◽  
Ed Landing
Keyword(s):  
New Species ◽  
Nova Scotia ◽  
North America ◽  
New Brunswick ◽  
Lower Cambrian ◽  
Early Cambrian ◽  
The West ◽  
Middle Cambrian ◽  
Sequence Stratigraphic ◽  
Two New Species

The Hanford Brook Formation, one of the classic Cambrian units of Avalonian North America, contains at least eight species of endemic trilobites, including Berabichia milleri Westrop n. sp., that are assigned to seven genera. The vertical succession of faunas is far more complex than has been recognized previously, with each member containing a lithofacies-specific assemblage. These are, in ascending order: a bradoriid-linguloid Association without trilobites in the nearshore St. Martin's Member, a Protolenus Association in dysaerobic siltstones and sandstones of the Somerset Street Member, and a Kingaspidoides-Berabichia Association in hummocky cross-stratified sandstones of the Long Island Member that overlie a parasequence boundary at Hanford Brook. Due to the breakdown of biogeographic barriers in the late Early Cambrian, two new species-based zones, the Protolenus elegans and Kingaspidoides cf. obliquoculatus zones, share trilobite genera with the Tissafinian Stage of Morocco. This generic similarity has been the basis for correlation of this upper Lower Cambrian interval on the Avalon continent with the West Gondwanan lowest Middle Cambrian. However, the clear facies control on the occurrence of genera in the Hanford Brook Formation and the presence of an abrupt faunal break and unconformity at the base of the Tissafinian in Morocco makes this correlation questionable. The Hanford Brook Formation may represent a late Early Cambrian interval unknown in Gondwana. Sequence-stratigraphic criteria even raise the possibility that the Protolenus Association is the biofacies equivalent of Callavia broeggeri Zone faunas of the Brigus Formation of Newfoundland, Nova Scotia and Massachusetts.

scholarly journals THE DEMOSPONGE GENUS LEPTOMITUS and A NEW SPECIES FROM THE MIDDLE CAMBRIAN OF SPAIN

Palaeontology ◽  
2007 ◽  
Vol 50 (2) ◽  
pp. 467-478 ◽  
Author(s):  
DIEGO C. GARCÍA-BELLIDO ◽  
RODOLFO GOZALO ◽  
JUAN B. CHIRIVELLA MARTORELL ◽  
ELADIO LIÑÁN
Keyword(s):  
New Species ◽  
Middle Cambrian ◽  
A New Species

Early Cambrian palaeoscolecid cuticles from Shaanxi, China

1996 ◽  
Vol 70 (2) ◽  
pp. 275-279 ◽  
Author(s):  
Xi-Guang Zhang ◽  
Brian R. Pratt
Keyword(s):  
New Species ◽  
Geographic Distribution ◽  
Lower Cambrian ◽  
New Genus ◽  
Three Dimensional ◽  
Early Cambrian ◽  
Middle Cambrian ◽  
High Diversity

Phosphatized, three-dimensional cuticle fragments of the palaeoscolecids Houscolex lepidotus new genus and new species, Houscolex species indeterminate, and an unidentified form are described from the Lower Cambrian Qiongzhusi Formation of Shaanxi, China. These segmented worms, characterized by regularly arranged simple plates and platelets, small circular pores and fine pits, and irregularly distributed nipplelike protuberances, are unique among known palaeoscolecids. The occurrence of such cuticles as seemingly persistent elements of phosphatized faunas suggests that wormlike organisms achieved a fairly high diversity and widespread geographic distribution during the Early and Middle Cambrian.

Middle Cambrian of Avalonian Massachusetts: Stratigraphy and correlation of the Braintree trilobites

2001 ◽  
Vol 75 (1) ◽  
pp. 116-135 ◽  
Author(s):  
Gerd Geyer ◽  
Ed Landing
Keyword(s):  
New Species ◽  
North America ◽  
Early Cambrian ◽  
Middle Cambrian ◽  
First Report ◽  
Senior Synonym ◽  
Low Diversity ◽  
Eastern Massachusetts

Although Middle Cambrian trilobites of the Braintree Member in eastern Massachusetts were among the first published on in North America, re-examination of this fauna has led to wholesale taxonomic and biostratigraphic re-evaluation. This low diversity fauna now includes at least seven species, with the first report of agnostoids (three poorly preserved taxa) and the ellipsocephalid Kingaspis avalonensis new species. Paradoxides (Acadoparadoxides) harlani Green emend., a senior synonym of P. (A.) haywardi Raymond, allows correlation into the lowest Middle Cambrian elsewhere in Avalon. However, all the polymeroid species are endemic, and this precludes a highly resolved correlation into other Cambrian paleocontinents. A breakdown of provincial barriers in the late Early Cambrian as western Gondwana passed from equatorial to the higher south latitudes of Avalon led to faunal exchanges between these continents. Paradoxides (Acadoparadoxides) and Kingaspis of the Braintree fauna are shared with western Gondwana, while Braintreella and “Agraulos” quadrangularis are closest to genera known from the Spanish, Moroccan, and Perunican (Bohemian) margins of Gondwana.

Ontogeny of a New Species of the Cambrian Series 3 (Middle Cambrian) Trilobite GenusLiostracinaMonke, 1903 from North China and the Taxonomic Position of the Superfamily Trinucleoidea

2014 ◽  
Vol 88 (2) ◽  
pp. 395-402 ◽  
Author(s):  
Tae-Yoon S. Park ◽  
Ji-Hoon Kihm ◽  
Imseong Kang ◽  
Duck K. Choi
Keyword(s):  
New Species ◽  
Evolutionary History ◽  
North China ◽  
Sister Group ◽  
Shandong Province ◽  
Taxonomic Position ◽  
Traditional Concept ◽  
Middle Cambrian ◽  
Cambrian Trilobite ◽  
A New Species

The Order Asaphida was grouped by the presence of a ventral median suture and a globular protaspis. The Superfamily Trinucleoidea has been assigned to the Order Asaphida, based on the recognition of a globular protaspis in the Ordovician representatives of the group, and the presence of a ventral median suture in the middle Cambrian genusLiostracinawhich has been regarded as a primitive sister-group to the post-Cambrian trinucleoideans. Recent studies demonstrate that the ventral median suture and the globular protaspis could have evolved multiple times in the trilobite evolutionary history, casting doubt on the traditional concept of the Order Asaphida. Inclusion of the Trinucleoidea into the Order Asaphida, therefore, has to be tested. It has recently been revealed thatLiostracina simesiJago and Cooper, 2005 did not possess a ventral median suture, implying that there could have been variable types of ventral suture within the genusLiostracina. Here we report the ontogeny ofLiostracina tangwangzhaiensisn. sp. from the Cambrian Series 3 (middle Cambrian) strata of Shandong Province of North China. The material for this study includes protaspides, which are of flat, benthic morphology, contrasting to the globular protaspid morphology of the Ordovician trinucleoideans. The benthic protaspid morphology ofL. tangwangzhaiensisindicates an independent evolution of the globular protaspis within the Superfamily Trinucleoidea. Together with the variable types of ventral suture within the genusLiostracina, the benthic protaspid morphology ofLiostracinaleads us to propose that the Superfamily Trinucleoidea be excluded from the Order Asaphida.

scholarly journals New records of Burgess Shale-type taxa from the middle Cambrian of Utah

2015 ◽  
Vol 89 (3) ◽  
pp. 411-423 ◽  
Author(s):  
Simon Conway Morris ◽  
Paul A. Selden ◽  
Glade Gunther ◽  
Paul G. Jamison ◽  
Richard A. Robison
Keyword(s):  
New Species ◽  
North America ◽  
Northwest Territories ◽  
Type Species ◽  
New Records ◽  
Western North America ◽  
Burgess Shale ◽  
Middle Cambrian ◽  
Stem Group ◽  
A New Species

AbstractCambrian strata of the Laurentian craton contain numerous examples of Burgess Shale–type faunas. Although displaying a more or less concentric distribution around the cratonal margin, most faunal occurrences are in present-day western North America, extending from the Northwest Territories to California. Nevertheless, the soft-bodied and lightly skeletalized fossils in most of these Lagerstätten are highly sporadic. Here, we extend knowledge of such Middle Cambrian occurrences in Utah with reports of four taxa. An arthropod from the Marjum Formation, Dytikosicula desmatae gen. et sp. nov., is a putative megacheiran. It is most similar to Dicranocaris guntherorum, best known from the younger Wheeler Formation, but differs primarily in the arrangement of pleurae and overall size. Along with a specimen of ?Yohoia sp, a new species of Yohoia, Y. utahana sp. nov., is described. It differs from the type and only known species, Y. tenuis, principally in its larger size and shorter exopods; it is the first description of this genus from outside the Burgess Shale. A new species of a stem-group lophotrochozoan from the Spence Shale, Wiwaxia herka sp. nov., possesses a palisade of dorso-lateral spines that are more robust and numerous than the type species of Wiwaxia, W. corrugata. Another notable taxon is Eldonia ludwigi from the Marjum Formation, which is interpreted as a primitive ambulacrarian (assigned to the cambroernids) and a new specimen of the ?cnidarian Cambrorhytium from the Wheeler Shale is illustrated.

Middle Cambrian arthropods from Utah

2008 ◽  
Vol 82 (2) ◽  
pp. 238-254 ◽  
Author(s):  
Derek E. G. Briggs ◽  
Bruce S. Lieberman ◽  
Jonathan R. Hendricks ◽  
Susan L. Halgedahl ◽  
Richard D. Jarrard
Keyword(s):  
New Species ◽  
New Genera ◽  
Burgess Shale ◽  
Separate Species ◽  
Middle Cambrian ◽  
Stem Group ◽  
New Material ◽  
A New Species

The Middle Cambrian Spence Shale Member (Langston Formation) and Wheeler and Marjum Formations of Utah are known to contain a diverse soft-bodied fauna, but important new paleontological material continues to be uncovered from these strata. New specimens of anomalocaridids include the largest and smallest near complete examples yet reported from Utah. New material of stem group arthropods includes two new genera and species of arachnomorphs: Nettapezoura basilika and Dicranocaris guntherorum. Other new arachnomorph material includes a new species of Leanchoilia comparable to L. protogonia Simonetta, 1970; Leanchoilia superlata? Walcott, 1912; Sidneyia Walcott, 1911a; and Mollisonia symmetrica Walcott, 1912. L. protogonia from the Burgess Shale is confirmed as a separate species and is not a composite fossil. The first example of the trilobite Elrathia kingii preserving traces of the appendages is described. In addition, new material of the bivalved arthropods Canadaspis Novozhilov in Orlov, 1960; Branchiocaris Briggs, 1976; Waptia Walcott, 1912; and Isoxys Walcott, 1890 is described.

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