Two Unusual Small Shelly Fossils from the Lower Cambrian of Southeastern Shaanxi Province, China

2014 ◽  
Vol 88 (2) ◽  
pp. 348-358 ◽  
Author(s):  
John L. Moore ◽  
Susannah M. Porter ◽  
Guoxiang Li
Keyword(s):  
Lower Cambrian ◽  
New Genus ◽  
Shaanxi Province ◽  
Early Cambrian ◽  
New Genus And Species ◽  
Small Shelly Fossils ◽  
Dengying Formation ◽  
Phylogenetic Affinities ◽  
Source Of Information ◽  
Made In

Phosphatized and phosphatic small shelly fossils are a major source of information concerning the evolution of animals during the early Cambrian. Although progress has been made in understanding some of these fossils, many remain enigmatic, both with regard to their phylogenetic affinities and the overall morphology of the animal from which isolated sclerites came. Two unusual fossils from the upper lower Cambrian (Qiongzhusian or Atdabanian) Xihaoping Member of the Dengying Formation from Xiaowan, Xixiang County, southeastern Shaanxi Province, China are described herein. The first of these is a cap-shaped fossil we describe asCambroskiadeion xiaowanensenew genus and species. On its concave surface it bears a spine, the base of which is covered with numerous hemispherical verruculae. The long spine indicates that this was a sclerite rather than a univalved shell, although it remains unclear from what sort of animal it came. Similar fossils have been hypothesized to be halkieriid valves; although the rarity of halkieriid sclerites in the present samples argues against this view, it is possible these fossils are part of a similar multi-element skeleton. The second fossil isAcidocharacus longiconusQin and Ding, 1988; it is known only from the Xihaoping Member and consists of a tall spine, often bearing barbs or bumps, attached to a rounded conical base. The base is covered with verruculae similar to those found onCambroskiadeion. The function of these elements, and whether they were internal or external, remains unknown.

A new modular palaeopascichnid fossil Curviacus ediacaranus new genus and species from the Ediacaran Dengying Formation in the Yangtze Gorges area of South China

2017 ◽  
Vol 154 (6) ◽  
pp. 1257-1268 ◽  
Author(s):  
BING SHEN ◽  
SHUHAI XIAO ◽  
CHUANMING ZHOU ◽  
LIN DONG ◽  
JIEQIONG CHANG ◽  
...  
Keyword(s):  
South China ◽  
New Genus ◽  
Three Dimensional ◽  
Internal Anatomy ◽  
Carbonate Facies ◽  
New Genus And Species ◽  
Modular Organisms ◽  
Dengying Formation ◽  
Body Construction ◽  
Phylogenetic Affinities

AbstractNon-biomineralizing Ediacaran macrofossils are rare in carbonate facies, but they offer valuable information about their three-dimensional internal anatomy and can broaden our view about their taphonomy and palaeoecology. In this study, we report a new Ediacaran fossil, Curviacus ediacaranus new genus and species, from bituminous limestone of the Shibantan Member of the Dengying Formation in the Yangtze Gorges area of South China. Curviacus is reconstructed as a benthic modular organism consisting of serially arranged and crescent-shaped chambers. The chambers are confined by chamber walls that are replicated by calcispars, and are filled by micritic sediments. Such modular body construction is broadly similar to the co-occurring Yangtziramulus zhangii and other Ediacaran modular fossils, such as Palaeopascichnus. The preservation style of Curviacus is similar to Yangtziramulus, although the phylogenetic affinities of both genera remain unresolved. The new fossil adds to the diversity of Ediacaran modular organisms.

A new early Cambrian bradoriid (Arthropoda) from East Antarctica

2003 ◽  
Vol 77 (4) ◽  
pp. 691-697 ◽  
Author(s):  
Alycia L. Rode ◽  
Bruce S. Lieberman ◽  
A. J. Rowell
Keyword(s):  
Lower Cambrian ◽  
New Genus ◽  
Sister Group ◽  
East Antarctica ◽  
Sister Group Relationship ◽  
Early Cambrian ◽  
New Genus And Species ◽  
The Family ◽  
Relationship Of

Although bradoriids locally are common components of the Cambrian biota, they have been reported previously from Antarctica only from Tertiary glacial deposits. Here, we describe the bradoriid,Bicarinella evansinew genus and species, collected in situ from the upper Lower Cambrian (Botomian) of the Pensacola Mountains in East Antarctica.Bicarinella evansin. gen and sp. is characterized by a subtriangular carapace with a well-defined marginal rim, subequal anterior and posterior lobes that are elongated into sharp ridges extending one-third the length of the carapace, and a broad dorsal node placed between the anterior and posterior lobes. The surface of the carapace exhibits three kinds of ornamentation: fine pitting, pustules, and reticulae. Several smaller carapaces with reduced ornamentation collected from the same bed are interpreted as instars of this species.Bicarinellan. gen. is assigned to the family Hipponicharionidae and appears to be closely related toAlbrunnicolaMartinsson, 1979, orHipponicharionMatthew, 1886. Although strong archaeocyath faunal similarities demonstrate a close biogeographic relationship between Australia and Antarctica in the Early Cambrian, the possible sister group relationship ofBicarinellan. gen. toHipponicharion, which is otherwise unknown from Gondwana, may suggest a separate biogeographic pathway to East Antarctica that did not involve Australia.

A new obolellid brachiopod from the Lower Cambrian of Morocco

1994 ◽  
Vol 68 (5) ◽  
pp. 995-1002 ◽  
Author(s):  
Gerd Geyer
Keyword(s):  
Lower Cambrian ◽  
New Genus ◽  
Early Cambrian ◽  
New Genus And Species

A new genus and species of obolellid brachiopod, Brevipelta chouberti, is described from the Early Cambrian of Morocco. It is a useful index fossil for the upper Choubertella Zone and the Daguinaspis Zone in Morocco. Additionally discussed are taphonomic aspects that lead to the question whether the shell may have been weakly calcified compared to other obolellid brachiopods and the calcareous part may have been composed of aragonite crystallites, or whether the preservation of Brevipelta is due to facile solubility of a calcitic shell substance. Brevipelta chouberti represents not only the oldest described Early Cambrian brachiopod from Africa, but one of the oldest obolellid brachiopods known worldwide.

Zhengica cornuta gen. nov., sp. nov., a new genus and species of Pentatomidae from East Asia (Hemiptera: Heteroptera)

Zootaxa ◽  
2021 ◽  
Vol 5071 (2) ◽  
pp. 271-282
Author(s):  
DÁVID RÉDEI ◽  
JING-FU TSAI
Keyword(s):  
East Asia ◽  
New Genus ◽  
New Genus And Species ◽  
Heteroptera Pentatomidae ◽  
Phylogenetic Affinities

Zhengica cornuta gen. nov., sp. nov. (Hemiptera: Heteroptera: Pentatomidae: Pentatominae: Pentatomini) from Shanxi, China, is described, illustrated, and its phylogenetic affinities are discussed. The genus is recognized as a generalized member of the clade of Pentatoma Olivier, 1789 and related genera, its phylogenetically closest relative is probably Cervicoris Hsiao & Cheng, 1977.  

A rare onychophoran-like lobopodian from the Lower Cambrian Chengjiang Lagerstätte, southwestern China, and its phylogenetic implications

2011 ◽  
Vol 85 (3) ◽  
pp. 587-594 ◽  
Author(s):  
Qiang Ou ◽  
Jianni Liu ◽  
Degan Shu ◽  
Jian Han ◽  
Zhifei Zhang ◽  
...  
Keyword(s):  
Lower Cambrian ◽  
New Genus ◽  
Southwestern China ◽  
New Taxon ◽  
New Genus And Species ◽  
Phylogenetic Implications ◽  
New Form ◽  
Close Relatives ◽  
Chengjiang Fossil Lagerstätte ◽  
Chengjiang Lagerstätte

Lobopodians, which diversified and flourished in the Cambrian seas, have long drawn much attention in that not only their extant close relatives, onychophorans and tardigrades, but euarthropods (Chelicerata, Myriapoda, Crustacea, and Hexapoda) may have been deeply rooted in stem-group lobopodians. Antennacanthopodia gracilis new genus and species is described and interpreted here as an “unarmoured” lobopodian from the Chengjiang fossil Lagerstätte (Early Cambrian, —520 Ma), Yunnan, southwestern China. This animal shares with other known Cambrian lobopodians such plesiomorphies (primitive characters) as onychophoran-like overall appearance; a metamerically segmented body covered by slightly sclerotized cuticle, and paired, unjointed lobopodal legs. Antennacanthopodia is also featured by a pair of frontal antennae, potential ocellus-like lateral visual organs, second antennae, a straight, voluminous midgut, diminutive spines arrayed on the leg and the trunk, well-developed leg musculature, highly sclerotized terminal leg pads, and presumptively a pair of posteriormost appendicules. This new taxon, with innovative characters (autapomorphies), furthers our understanding of early lobopodian diversification. Antennacanthopodia is considered closely allied to extant Onychophora based on considerable anatomical similarities. Taken together its “two-segmented” cephalization and appendage-bearing “ocular segment”, this new form may shed some new light on the arthropod groundplan.

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.

The Placentian Series: appearance of the oldest skeletalized faunas in southeastern Newfoundland

1989 ◽  
Vol 63 (6) ◽  
pp. 739-769 ◽  
Author(s):  
Ed Landing ◽  
Paul Myrow ◽  
Alison P. Benus ◽  
Guy M. Narbonne
Keyword(s):  
Lower Cambrian ◽  
Early Cambrian ◽  
Island Formation ◽  
Left Handed ◽  
Small Shelly Fossils ◽  
Body Fossil ◽  
Offshore Muds ◽  
Block Faulting ◽  
Phosphate Deposits ◽  
High Diversity

The lowest Cambrian of Avalon, or Placentian Series, is a relatively thick sequence (1,400 m) in southeastern Newfoundland. A newly proposed body fossil zonation supplements an existing trace fossil zonation of the lower part of the Placentian Series and includes strata to the top of the sub-trilobitic Lower Cambrian.The Sabellidites cambriensis Zone brackets the Precambrian–Cambrian boundary and comprises peritidal and wave-influenced subtidal facies deposited during deepening through the lower part of the Chapel Island Formation. Younger “Ladatheca” cylindrica Zone strata include the deepest facies of the Chapel Island Formation. The base of the overlying Watsonella crosbyi Zone (a post-Nemakit Daldyn and pre-Tommotian equivalent) is significantly diachronous because the diagnostic mollusks were preferentially preserved in pyritiferous offshore muds rather than in coeval nearshore muds. High diversity, upper Watsonella crosbyi Zone faunas (18 species) are limited to peritidal limestones of member 4 and are dominated by calcareous small shelly fossils. A thick interval (ca. 430 m) without body fossils and an important episode of block faulting that led to 750 m of differential erosion preceded deposition of the lower part of the Bonavista Group (=Sunnaginia imbricata Zone, an interval considered to be largely older than the Tommotian). Although much Early Cambrian time may be lost as a result of erosion at Random Formation–Bonavista Group unconformities, many Watsonella crosbyi Zone species reappear in the Sunnaginia imbricata Zone. Shoaling accompanied the immigration event defining the base of the Camenella baltica Zone, and an unconformity following regional offlap marks the top of the Placentian Series.Calcareous, and not phosphatic, composition is most common in earliest Cambrian shelly remains. Little evidence suggests that a global, Precambrian–Cambrian boundary interval “phosphogenic” event either resulted in deposition of local phosphate deposits in the Tethyan region or had a role in the appearance of mineralized skeletons.Twenty metazoans and problematica and an alga are illustrated from the Chapel Island Formation. Bemella? vonbitteri Landing n. sp. and Halkieria stonei Landing n. sp. are described. The monoplacophoran Archaeospira? avalonensis Landing n. sp. has right-and left-handed conchs comparable to those of Archaeospira (=Yangtzespira) from China. Anabarites is the senior generic synonym of Tiksitheca.

scholarly journals A new enigmatic Late Miocene mylodontoid sloth from northern South America

2015 ◽  
Vol 2 (2) ◽  
pp. 140256 ◽  
Author(s):  
Ascanio D. Rincón ◽  
H. Gregory McDonald ◽  
Andrés Solórzano ◽  
Mónica Núñez Flores ◽  
Damián Ruiz-Ramoni
Keyword(s):  
South America ◽  
Late Miocene ◽  
Preliminary Analysis ◽  
New Genus ◽  
New Taxon ◽  
New Genus And Species ◽  
Consensus Tree ◽  
Discriminate Analysis ◽  
Northern South America ◽  
Phylogenetic Affinities

A new genus and species of sloth ( Eionaletherium tanycnemius gen. et sp. nov.) recently collected from the Late Miocene Urumaco Formation, Venezuela (northern South America) is herein described based on a partial skeleton including associated femora and tibiae. In order to make a preliminary analysis of the phylogenetic affinities of this new sloth we performed a discriminate analysis based on several characters of the femur and tibia of selected Mylodontoidea and Megatherioidea sloths. The consensus tree produced indicates that the new sloth, E. tanycnemius , is a member of the Mylodontoidea. Surprisingly, the new taxon shows some enigmatic features among Neogene mylodontoid sloths, e.g. femur with a robust lesser trochanter that projects medially and the straight distinctly elongated tibia. The discovery of E. tanycnemius increases the diversity of sloths present in the Urumaco sequence to ten taxa. This taxon supports previous studies of the sloth assemblage from the Urumaco sequence as it further indicates that there are several sloth lineages present that are unknown from the better sampled areas of southern South America.

A probable late Neoproterozoic age for the Kennedy Channel and Ella Bay formations, northeastern Ellesmere Island and its implications for passive margin history of the Canadian Arctic

2004 ◽  
Vol 41 (9) ◽  
pp. 1013-1025 ◽  
Author(s):  
Keith Dewing ◽  
J C Harrison ◽  
Brian R Pratt ◽  
Ulrich Mayr
Keyword(s):  
Lower Cambrian ◽  
Canadian Arctic ◽  
Passive Margin ◽  
Early Cambrian ◽  
Channel Formation ◽  
Type Section ◽  
Small Shelly Fossils ◽  
History Of ◽  
Basin Formation ◽  
Late Neoproterozoic

The Kennedy Channel and Ella Bay formations are the two oldest stratigraphic units exposed in the Franklinian margin sedimentary sequence in the Canadian Arctic Islands. An Early Cambrian age had previously been accepted by the occurrence of trilobites and small shelly fossils in the type section of the Kennedy Channel Formation. Reinvestigation of the area around the type section shows that several large strike-slip faults cut the succession and that the olenelloid trilobites are from an infaulted slice of a younger unit, the Lower Cambrian Kane Basin Formation. Thus, there is no unambiguous paleontological evidence for the age of either the Kennedy Channel or Ella Bay formations. However, the abundance of stromatolites, absence of trace fossils, and separation from overlying Lower Cambrian clastics by a regional angular unconformity indicate a probable late Neoproterozoic age for these two formations. The Ella Bay Formation likely correlates with the Portfjeld Formation in North Greenland, the Spiral Creek Formation in East Greenland, and the Risky Formation of the Mackenzie Mountains in northwestern Canada. The passive margin that existed in northern Laurentia during the early Paleozoic was, therefore, established in the late Neoproterozoic, and the onset of rifting must have preceded this, rather than occurring in the Early Cambrian as some authors have suggested.

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