ACloudina-like fossil with evidence of asexual reproduction from the lowest Cambrian, South China

2017 ◽  
Vol 154 (6) ◽  
pp. 1294-1305 ◽  
Author(s):  
JIAN HAN ◽  
YAOPING CAI ◽  
JAMES D. SCHIFFBAUER ◽  
HONG HUA ◽  
XING WANG ◽  
...  
Keyword(s):  
Asexual Reproduction ◽  
South China ◽  
Fossil Record ◽  
Tube Wall ◽  
Shaanxi Province ◽  
Branching Structures ◽  
Southern Shaanxi ◽  
Wall Construction ◽  
Evolutionary Continuity ◽  
Evolutionary Fate

AbstractThe earliest fossil record of animal biomineralization occurs in the latest Ediacaran Period (c. 550 Ma).CloudinaandSinotubulitesare two important tubular taxa among these earliest skeletal fossils. The evolutionary fate ofCloudina-type fossils across the Ediacaran–Cambrian transition, however, remains poorly understood. Here we report a multi-layered tubular microfossilFeiyanella manicagen. et sp. nov. from a phosphorite interval of the lowest Cambrian Kuanchuanpu Formation, southern Shaanxi Province, South China. This newly discovered fossil is a conical tube with a ‘funnel-in-funnel’ construction, showing profound morphological similarities toCloudinaandConotubus. On the other hand, the outer few layers, and particularly the outermost layer, ofFeiyanellatubes are regularly to irregularly corrugated, a feature strikingly similar to the variably folded/wrinkled tube walls ofSinotubulites. TheFeiyanellatubes additionally exhibit two orders of dichotomous branching, similar to branching structures reported occasionally inCloudinaand possibly indicative of asexual reproduction. Owing to broad similarities in tube morphology, tube wall construction and features presumably indicative of asexual reproduction,Cloudina, Conotubus, Sinotubulitesand the here describedFeiyanellamay thus constitute a monophyletic group traversing the Ediacaran–Cambrian boundary. The tube construction and palaeoecological strategy ofFeiyanellaputatively indicate evolutionary continuity in morphology and palaeoecology of benthic metazoan communities across the Ediacaran–Cambrian transition.

Discussion of ‘First finds of problematic Ediacaran fossil Gaojiashania in Siberia and its origin’

2010 ◽  
Vol 148 (2) ◽  
pp. 329-333 ◽  
Author(s):  
Yaoping Cai ◽  
Hong Hua ◽  
Andrey Yu. Zhuravlev ◽  
José Antonio Gámez Vintaned ◽  
Andrey Yu. Ivantsov
Keyword(s):  
South China ◽  
Yunnan Province ◽  
North China ◽  
Guizhou Province ◽  
Shaanxi Province ◽  
Qinghai Province ◽  
Autonomous Region ◽  
Dengying Formation ◽  
Ningxia Hui Autonomous Region ◽  
Southern Shaanxi

Y. Cai & H. Hua comment: Zhuravlev, Gámez Vintaned & Ivantsov (2009) reported the problematic Ediacaran fossil Gaojiashania annulucosta in Siberia and they considered that this is the first find of Gaojiashania outside China, since Gaojiashania had previously only been reported from the Gaojiashan Member of the middle Dengying Formation in the Ningqiang area, southern Shaanxi Province, South China. However, we believe that the so-called Siberian Gaojiashania was mis-identified, and what was described as Gaojiashania annulucosta by Zhuravlev, Gámez Vintaned & Ivantsov (2009) is more appropriately ascribed to Shaanxilithes ningqiangensis, another problematic Ediacaran fossil that has also been known from the Gaojiashan Member in Shaanxi Province of South China (Chen, Chen & Lao, 1975; Xing et al. 1984), as well as the stratigraphically equivalent Taozichong Formation in Guizhou Province (Hua, Chen & Zhang, 2004) and the Jiucheng Member (Dengying Formation) in Yunnan Province of South China (Zhu & Zhang, 2005), the Zhoujieshan Formation in Qinghai Province (Shen et al. 2007), and the Zhengmuguan Formation in Ningxia Hui Autonomous Region of North China (Shen et al. 2007).

A fossil record of land plant origins from charophyte algae

Science ◽  
2021 ◽  
Vol 373 (6556) ◽  
pp. 792-796 ◽  
Author(s):  
Paul K. Strother ◽  
Clinton Foster
Keyword(s):  
Fossil Record ◽  
Evolutionary History ◽  
Phylogenetic Signal ◽  
Land Plant ◽  
Fossil Plants ◽  
Fossil Plant ◽  
Molecular Phylogenetic ◽  
History Of ◽  
Time Gap ◽  
Evolutionary Continuity

Molecular time trees indicating that embryophytes originated around 500 million years ago (Ma) during the Cambrian are at odds with the record of fossil plants, which first appear in the mid-Silurian almost 80 million years later. This time gap has been attributed to a missing fossil plant record, but that attribution belies the case for fossil spores. Here, we describe a Tremadocian (Early Ordovician, about 480 Ma) assemblage with elements of both Cambrian and younger embryophyte spores that provides a new level of evolutionary continuity between embryophytes and their algal ancestors. This finding suggests that the molecular phylogenetic signal retains a latent evolutionary history of the acquisition of the embryophytic developmental genome, a history that perhaps began during Ediacaran-Cambrian time but was not completed until the mid-Silurian (about 430 Ma).

scholarly journals A ‘Giant Microfossil’ from the Gunflint Chert and its Implications for Fungal and Eukaryote Origins

2019 ◽  
Author(s):  
Mark A. S. McMenamin ◽  
Aurora Curtis-Hill ◽  
Sophie Rabinow ◽  
Kalyndi Martin ◽  
Destiny Treloar
Keyword(s):  
Thin Section ◽  
Asexual Reproduction ◽  
Alternaria Alternata ◽  
Fossil Record ◽  
Iron Formation ◽  
Southern Ontario ◽  
Large Size ◽  
Early Evidence

We report here a giant microfossil resembling the conidium of an ascomycete fungus (cf. Alternaria alternata). The specimen is preserved in stromatolitic black chert of the Gunflint Iron Formation (Paleoproterozoic Eon, Orosirian Period, ca. 1.9-2.0 Ga) of southern Ontario, Canada, and the rock that provided the thin section may have been collected by Elso Barghoorn as part of the original discovery of the Gunflint microbiota. The large size of the fossil sets it apart from other, tiny by comparison, Gunflint microfossils. The fossil is 200 microns in length and has cross walls. Individual cells are 30-46 microns in greatest dimension. The apical ‘spore’ is cap-shaped, and has partly separated from the rest of the structure. Cloulicaria gunflintensis gen. nov. sp. nov. may provide early evidence for eukaryotes (fungi) in the fossil record, and may also represent the earliest evidence for asexual reproduction in a eukaryote by means of mitospores.

scholarly journals A ‘Giant Microfossil’ from the Gunflint Chert and its Implications for Eukaryote Origins

2019 ◽  
Author(s):  
Mark McMenamin
Keyword(s):  
Thin Section ◽  
Asexual Reproduction ◽  
Alternaria Alternata ◽  
Fossil Record ◽  
Iron Formation ◽  
Southern Ontario ◽  
Large Size ◽  
Early Evidence

We report here a ‘giant microfossil’ resembling the conidium of an ascomycete fungus (cf. Alternaria alternata). The specimen is preserved in stromatolitic black chert of the Gunflint Iron Formation (Paleoproterozoic Eon, Orosirian Period, ca. 1.9-2.0 Ga) of southern Ontario, Canada, and the rock that provided the thin section may have been collected by Elso Barghoorn as part of the original discovery of the Gunflint microbiota. The large size of the fossil sets it apart from other, tiny by comparison, Gunflint microfossils. The fossil is 200 microns in length and has cross walls. Individual cells are 30-46 microns in greatest dimension. The apical ‘spore’ is cap-shaped, and has partly separated from the rest of the structure. Cloulicaria gunflintensis gen. nov. sp. nov. may provide early evidence for eukaryotes (fungi) in the fossil record, and may also represent the earliest evidence for asexual reproduction in a eukaryote by means of mitospores.

Countering Common Misconceptions of Evolution in the Paleontology Classroom

2012 ◽  
Vol 12 ◽  
pp. 109-122
Author(s):  
Keith B. Miller
Keyword(s):  
Fossil Record ◽  
Temporal Pattern ◽  
Historical Context ◽  
Evolutionary Trees ◽  
Teaching Evolution ◽  
New Knowledge ◽  
Evolutionary Science ◽  
Taxonomic Groups ◽  
Scientific Testing ◽  
Evolutionary Continuity

Students will come to class with misconceptions about evolution and about the nature of science itself. Erroneous views that create obstacles to teaching evolution include: 1) that the fossil record does not support evolutionary continuity between different taxonomic groups; 2) that the expected temporal pattern of evolution is linear and ladder-like; and 3) that evolutionary hypotheses are not subject to scientific testing. These views negatively impact the understanding of evolutionary science, particularly paleontology, in a number of ways. It is important that these misconceptions be recognized and explicitly countered. If student's false ideas are left unaddressed, new knowledge presented in the classroom will likely simply be superimposed on, or integrated with them. Effective teaching thus requires that we not only impart new knowledge, but seek to correct previously held false ideas. This essay presents several teaching strategies that can address misconceptions about evolution. These include: 1) teaching important concepts in their historical context; 2) having students construct and interpret cladograms; and 3) showing that, when interpreted as evolutionary trees, cladograms make testable predictions of the fossil record.

scholarly journals Changes in the epidemiological characteristics of human brucellosis in Shaanxi Province from 2008 to 2020

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cui-hong An ◽  
Zhi-guo Liu ◽  
Shou-min Nie ◽  
Yang-xin Sun ◽  
Suo-ping Fan ◽  
...  
Keyword(s):  
Incidence Rate ◽  
Large Scale ◽  
Small Ruminants ◽  
Raw Milk ◽  
Shaanxi Province ◽  
Significant Feature ◽  
Human Brucellosis ◽  
Northern Shaanxi ◽  
Southern Shaanxi ◽  
Epidemiological Characteristics

AbstractIn the present study, surveys of case numbers, constituent ratios, conventional biotyping, and multilocus sequence typing (MLST) were applied to characterize the incidence rate and epidemiological characteristics of human brucellosis in Shaanxi Province, China. A total of 12,215 human brucellosis cases were reported during 2008–2020, for an annual average incidence rate of 2.48/100,000. The most significant change was that the county numbers of reported cases increased from 36 in 2008 to 84 in 2020, with a geographic expansion trend from northern Shaanxi to Guanzhong, and southern Shaanxi regions; the incidence rate declined in previous epidemic northern Shaanxi regions while increasing each year in Guanzhong and southern Shaanxi regions such as Hancheng and Xianyang. The increased incidence was closely related to the development of large-scale small ruminants (goats and sheep) farms in Guanzhong and some southern Shaanxi regions. Another significant feature was that student cases (n = 261) were ranked second among all occupations, accounting for 2.14% of the total number of cases, with the majority due to drinking unsterilized goat milk. Three Brucella species were detected (B. melitensis (bv. 1, 2, 3 and variant), B. abortus bv. 3/6, and B. suis bv. 1) and were mainly distributed in the northern Shaanxi and Guanzhong regions. Three known STs (ST8, ST2, and ST14) were identified based on MLST analysis. The characteristics that had not changed were that B. melitensis strains belonging to the ST8 population were the dominant species and were observed in all nine regions during the examined periods. Strengthened human and animal brucellosis surveillance and restriction of the transfer of infected sheep (goats) as well as students avoiding drinking raw milk are suggested as optimal control strategies.

scholarly journals Enduring evolutionary embellishment of cloudinids in the Cambrian

2021 ◽  
Vol 8 (12) ◽  
Author(s):  
Tae-Yoon S. Park ◽  
Jikhan Jung ◽  
Mirinae Lee ◽  
Sangmin Lee ◽  
Yong Yi Zhen ◽  
...  
Keyword(s):  
Asexual Reproduction ◽  
Fossil Record ◽  
Evolutionary History ◽  
Structural Complexity ◽  
Cambrian Explosion ◽  
Animal Group ◽  
Reproduction Mode ◽  
First Case ◽  
History Of ◽  
Mode Tracking

The Ediacaran–Cambrian transition and the following Cambrian Explosion are among the most fundamental events in the evolutionary history of animals. Understanding these events is enhanced when phylogenetic linkages can be established among animal fossils across this interval and their trait evolution monitored. Doing this is challenging because the fossil record of animal lineages that span this transition is sparse, preserved morphologies generally simple and lifestyles in the Ediacaran and Cambrian commonly quite different. Here, we identify derived characters linking some members of an enigmatic animal group, the cloudinids, which first appeared in the Late Ediacaran, to animals with cnidarian affinity from the Cambrian Series 2 and the Miaolingian. Accordingly, we present the first case of an animal lineage represented in the Ediacaran that endured and diversified successfully throughout the Cambrian Explosion by embellishing its overall robustness and structural complexity. Among other features, dichotomous branching, present in some early cloudinids, compares closely with a cnidarian asexual reproduction mode. Tracking this morphological change from Late Ediacaran to the Miaolingian provides a unique glimpse into how a primeval animal group responded during the Cambrian Explosion.

scholarly journals Chemo- and biostratigraphy of the Gaojiashan section (northern Yangtze platform, South China): a new Pc-C boundary section

Fossil Record ◽  
2015 ◽  
Vol 18 (2) ◽  
pp. 105-117 ◽  
Author(s):  
A. Gamper ◽  
U. Struck ◽  
F. Ohnemueller ◽  
C. Heubeck ◽  
S. Hohl
Keyword(s):  
Shallow Water ◽  
South China ◽  
Shaanxi Province ◽  
Cambrian Explosion ◽  
Local Perturbation ◽  
Data Set ◽  
Carbonate Carbon ◽  
Dengying Formation ◽  
Isotope Record ◽  
Ediacaran Fauna

Abstract. The widespread, terminal Ediacaran Dengying Formation (~ 551–~ 542 Ma) of South China hosts one of the most prominent negative carbonate carbon isotope excursions in Earth's history and thus bears on the correlation of the Precambrian–Cambrian boundary worldwide. The dominantly carbonate strata of the Dengying Formation are largely studied for their unique preservation of its terminal Ediacaran fauna but their geochemical context is poorly known. This study presents the first high-resolution stable isotope record (δ13C, δ18O) of calcareous siliciclastic shallow-water deposits of the Gaojiashan section (Shaanxi Province). The section includes (in ascending order) the Algal Dolomite Member, the Gaojiashan Member and the Beiwan Member of the Dengying Formation. Our data record a major δ13Ccarb negative excursion to −6 ‰ in the uppermost Gaojiashan Member which is comparable in shape and magnitude to the global Precambrian–Cambrian boundary negative δ13C excursion. Our data set is consistent with a "shallow-water anoxia" scenario which is thought to contribute to the "Cambrian explosion". The stratigraphic occurrence of Cloudina and a large negative δ13C excursion suggest that the Precambrian–Cambrian boundary is located near the top of the Gaojiashan Member and, consequently, that overlying carbonates and dolomites of the Beiwan Member are of earliest Cambrian age. Thus the Gaojiashan section may represent a new shallow-water section spanning the Precambrian–Cambrian boundary. Although bio- and chemostratigraphic data support this novel interpretation, we cannot exclude the possibility that the key excursions may represent a local perturbation indicating a restricted-basin environment.

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