New artiopodan arthropods from the early Cambrian Emu Bay Shale Konservat-Lagerstätte of South Australia

2012 ◽  
Vol 86 (2) ◽  
pp. 340-357 ◽  
Author(s):  
John R. Paterson ◽  
Diego C. García-Bellido ◽  
Gregory D. Edgecombe
Keyword(s):  
Alimentary Tract ◽  
Three Dimensional ◽  
Cladistic Analysis ◽  
South Australia ◽  
First Record ◽  
Early Cambrian ◽  
Burgess Shale ◽  
Early Devonian ◽  
New Information ◽  
Stage 4

The Emu Bay Shale Konservat-Lagerstätte (Cambrian Series 2, Stage 4) on Kangaroo Island, South Australia, is the source of two new non-biomineralized artiopodan arthropods. Squamacula buckorum n. sp. is the first record outside of China of a genus otherwise known only from its type species, S. clypeata, from the Chengjiang biota. The Australian species displays the long cephalic doublure and spiniform exopod setae that are apomorphic for this genus, provides new information on the alimentary tract and midgut glands (the latter preserved as three-dimensional, permineralized structures), and indicates interspecific variability in trunk segment numbers. The distribution of Squamacula strengthens the biogeographic connections between early Cambrian “Burgess Shale-type” biotas of Australia and South China. Australimicola spriggi n. gen. n. sp. represents a monotypic genus resolved in a cladistic analysis of Cambro-Ordovician artiopodans as most closely related to or within Conciliterga (a clade containing Helmetia, Kuamaia, Kwanyinaspis, Rhombicalvaria, Saperion, Skioldia, and Tegopelte). Compared with other members of this clade from Chengjiang and the Burgess Shale, the new genus is diagnosed by an elongate trunk with 23 thoracic tergites having spatulate pleural tips and a small pygidium possessing a single, elongate pair of pleural spines, with specimens also showing a hypostome attached to an anterior (or prehypostomal) sclerite, antennae, short endopods, an annulated alimentary tract, and a series of three-dimensional, permineralized midgut glands. An alternative relationship between Australimicola and the Early Ordovician–Early Devonian Cheloniellida explains the shared anterior flexure of trunk pleurae but forces dubious homologies in other characters, such as dorsally-articulated furcae versus spines.

Herpetogaster from the early Cambrian of Nevada (Series 2, Stage 4) and its implications for the evolution of deuterostomes

2018 ◽  
Vol 156 (1) ◽  
pp. 172-178 ◽  
Author(s):  
JULIEN KIMMIG ◽  
RONALD C. MEYER ◽  
BRUCE S. LIEBERMAN
Keyword(s):  
Early Cambrian ◽  
Burgess Shale ◽  
Middle Cambrian ◽  
Stage 4 ◽  
First Occurrence

AbstractThe Pioche Formation of SE Nevada preserves a diverse soft-bodied fauna from the early and middle Cambrian (Series 2–3: Stage 4–5). While the fauna is dominated by arthropods, animals belonging to other taxa can be found. Here we document the first occurrence of Herpetogaster collinsi outside the Burgess Shale. Further, the specimens are from the Nephrolenellus multinodus biozone and thus represent the oldest occurrence of the species, as well as possibly the earliest soft-bodied deuterostomes in Laurentia.

scholarly journals Presence of Naraoia Walcott, 1912 (Nektaspida, Arthropoda) in the middle Cambrian of Europe (Murero, NE Spain)

2018 ◽  
Vol 33 (1) ◽  
pp. 83
Author(s):  
Rodolfo Gozalo ◽  
Mª Eugenia Dies-Álvarez ◽  
José Antonio Gámez VIintaned ◽  
Juan B. Chirivella ◽  
Eladio Liñan
Keyword(s):  
British Columbia ◽  
First Record ◽  
Early Cambrian ◽  
Burgess Shale ◽  
Evolutionary Potential ◽  
Middle Cambrian ◽  
The Family ◽  
Ne Spain

 The genus Naraoia Walcott, 1912, a Burgess Shale-type fossil known from the lower and middle Cambrian of British Columbia (Canada), Idaho and Utah (USA), as well as from Yunnan and Guizhou provinces (China), is now reported from the middle Cambrian of Murero (Zaragoza, Spain), which is the first record in the Acadobaltic province. The only fragmented specimen found is determined as Naraoia sp., its age being Pardailhania multispinosa Zone (Drumian Stage). This new datum reinforces the hypothesis of the existence of a cosmopolitan faunal substrate in early Cambrian times, which is to some extent refl ected in the mid Cambrian by faunal groups of low evolutionary potential as the family Naraoiidae and other soft-bodied fossil taxa.

A new arthropod Pygmaclypeatus daziensis from the Early Cambrian Chengjiang Lagerstätte, South China

2000 ◽  
Vol 74 (5) ◽  
pp. 979-982 ◽  
Author(s):  
Xingliang Zhang ◽  
Jian Han ◽  
Degan Shu
Keyword(s):  
South China ◽  
Fossil Record ◽  
South Australia ◽  
Early Cambrian ◽  
Burgess Shale ◽  
Closely Related Species ◽  
Stratigraphic Position ◽  
Chengjiang Lagerstätte ◽  
Early Metazoan ◽  
North Greenland

The early Cambrian Chengjiang Lagerstatte, generally regarded as late Atdabanian (Qian and Bengtson, 1989; Bengtson et al., 1990), has become celebrated for perhaps the earliest biota of soft-bodied organisms known from the fossil record and has proven to be critical to our understanding of early metazoan evolution. The Sirius Passet fauna from Peary Land, North Greenland, another important repository of soft-bodied and poorly sclerotized fossils, was also claimed as Early Cambrian (Conway Morris et al., 1987; Budd, 1995). The exact stratigraphic position of the Sirius Passet fauna (Buen Formation) is still uncertain, although the possibility of late Atdabanian age was proposed (Vidal and Peel, 1993). Recent work dates it in the “Nevadella” Biozone (Budd and Peel, 1998). It therefore appears to be simultaneous with or perhaps slightly younger than Chengjiang Lagerstatte, Eoredlichia Biozone (Zhuravlev, 1995). The Emu Bay Shale of Kangaroo Island, South Australia, has long been famous as a source of magnificent specimens of the trilobites Redlichia takooensis and Hsunaspis bilobata. It is additionally important as the only site in Australia so far to yield a Burgess-Shale-type biota (Glaessner, 1979; Nedin, 1992). The Emu Bay Shale was considered late Early Cambrian in age (Daily, 1956; Öpik, 1975). But Zhang et al.(1980) reassessed its age based on data from the Chinese Early Cambrian. The occurrence of Redlichia takooensis and closely related species of Hsunaspis indicates an equivalence to the Tsanglangpuian in the Chinese sequence, and the contemporary South Australia fauna correlate with the Botomian of Siberia (Bengtson et al., 1990). Thus the Emu Bay Shale is younger than the upper Atdabanian Chengjiang Lagerstatte, Chiungchussuian.

scholarly journals An exceptionally preserved euarthropod with unique feather-like appendages from the Chengjiang biota

2021 ◽  
Author(s):  
Dayou Zhai ◽  
Mark Williams ◽  
David J. Siveter ◽  
Derek J. Siveter ◽  
Thomas H.P. Harvey ◽  
...  
Keyword(s):  
Soft Part ◽  
Three Dimensional ◽  
Ct Scanning ◽  
Early Cambrian ◽  
Micro Ct ◽  
Burgess Shale ◽  
Terminal Seta ◽  
Stem Group ◽  
Chengjiang Biota

AbstractMicro-CT scanning of the Cambrian euarthropod Chuandianella ovata reveals unprecedented three-dimensional soft-part details. It has an elongate uniramous antennule and a short uniramous second appendage, followed by ten homonomous biramous appendages, each comprising a short paddle-shaped exopod and a unique feather-like endopod with at least 27 podomeres each of which bears a long blade-like endite with a short terminal seta. Based on its carapace and previously known soft-part anatomy C. ovata was compared with the Burgess Shale mandibulate euarthropod Waptia. However, Waptia has recently been shown to bear specialized head appendages that are interpreted as a mandible and maxillula, posterior to which are four appendages each with five-segmented endopods. In contrast, we interpret Chuandianella as an ‘upper’ stem-group euarthropod that possessed neither a differentiated mandible nor a maxillula. Chuandianella further demonstrates that early Cambrian ‘upper’ stem-group euarthropods were experimenting with a range of different limb arrangements and morphologies.

New paleoscolecid worms from the early Cambrian north margin of the Yangtze Platform, South China

2017 ◽  
Vol 92 (1) ◽  
pp. 49-58 ◽  
Author(s):  
Yuning Yang ◽  
Xingliang Zhang ◽  
Yuanlong Zhao ◽  
Yiru Qi ◽  
Linhao Cui
Keyword(s):  
South China ◽  
New Genus ◽  
Early Cambrian ◽  
New Taxon ◽  
Burgess Shale ◽  
Yangtze Platform ◽  
Mosaic Pattern ◽  
The North ◽  
Deposit Feeders ◽  
Stage 4

AbstractThe Cambrian Yanwangbian assemblage (Series 2, Stage 4) in South Shaanxi, China, is one of the Burgess Shale–type faunas as it represents the only relatively diverse Cambrian biota from the north margin of the Yangzte Platform, South China. The paleoscolecids (Cycloneuralia) illustrated herein are one of the major components of the fauna, although they appear to be much less abundant than skeletonized fossils, according to available collections. A new taxon, Shaanxiscolex xixiangensis new genus new species, is described based on the scleritome pattern: each annulus has two rows of alternating Hadimopanella-type plates positioned close to the borders, and a mosaic pattern of microplates occurs between the plates and within intersegmental furrows. The occurrence of the new taxon confirms a fairly diversified and widespread distribution of paleoscolecidan worms recognized in the early Cambrian of South China. Moreover, the ecology of paleoscolecids is reappraised based on burial position of the S. xixiangensis and gut contens of Cambrian taxa from South China, hinting that paleoscolecids (at least some taxa) were both deposit feeders and carnivores, as well as active bioturbators in the substrates of the Cambrian sea, which sheds new light on the ‘Cambrian Substrate Revolution.’

scholarly journals New early Cambrian sclerites ofLapworthella schodakensisfrom NE Greenland: advancements in knowledge of lapworthellid taxonomy, sclerite growth and scleritome organization

2016 ◽  
Vol 154 (5) ◽  
pp. 1061-1072 ◽  
Author(s):  
L. DEVAERE ◽  
C. B. SKOVSTED
Keyword(s):  
Early Ontogeny ◽  
Body Plan ◽  
Morphological Features ◽  
Early Cambrian ◽  
Shell Microstructure ◽  
Laminar Shell ◽  
Small Shelly Fossils ◽  
New Information ◽  
Stage 4 ◽  
Species Taxonomy

AbstractThe Cambrian Stage 4 upper Bastion Formation of Albert Heim Bjerge and CH Ostenfeld Nunatak, NE Greenland, yielded 34 excellently preserved sclerites ofLapworthella schodackensisamong other small shelly fossils. Lapworthellids have been interpreted as members of the camenellans, a basal tommotiid group. Little is known about this group although the morphological and ultrastructural features of their sclerites allow a potential reconstruction of a lophophorate body plan. The exquisite material from Greenland provides significant new data for the revision of the species taxonomy, but also for the comprehension of the scleritome structure of lapworthellids and the mode of formation of their sclerites. Two morphotypes ofL. schodackensissclerites are identified: one with a simple apex, occurring in sinistral and dextral forms; and one bilaterally symmetrical sclerite with two apices. All bear a similar ornamentation constructed of repeated growth sets consisting of a reticulate inter-rib groove with tubercles, a densely denticulate rib and a striated sub-rib area. The new data on the ornamentation and observations of the laminar shell microstructure ofL. schodackensisenable us to improve the reconstruction of growth in lapworthellids. Finally, the morphological features of the two types of sclerites provide new information for the reconstruction of the bilaterally symmetrical multi-component lapworthellid scleritome with evidence of the fusion of adjacent sclerites during early ontogeny.

scholarly journals Disc-shaped fossils resembling porpitids (Cnidaria: Hydrozoa) or eldonids from the early Cambrian (Series 2: Stage 4) of western U.S.A.

2017 ◽  
Author(s):  
Bruce S Lieberman ◽  
Richard Kurkewicz ◽  
Heather Shinogle ◽  
Julien Kimmig ◽  
Breandán Anraoi MacGabhann
Keyword(s):  
Iron Sulfide ◽  
Energy Dispersive ◽  
Early Cambrian ◽  
Elemental Mapping ◽  
Burgess Shale ◽  
X Ray ◽  
Element Carbon ◽  
Stage 4 ◽  
The Status

The morphology and affinities of newly discovered disc-shaped soft-bodied fossils from the early Cambrian (Series 2: Stage 4, Dyeran) Carrara Formation are discussed. These specimens show some similarity to the Ordovician Discophyllum Hall, 1847; traditionally this taxon had been treated as a fossil porpitid. However, recently it has instead been referred to another clade, the eldonids, which includes the enigmatic Eldonia Walcott, 1911 that was originally described from the Cambrian Burgess Shale. The status of various Proterozoic and Phanerozoic taxa previously referred to porpitids and eldonids is also briefly considered. To help ascertain that the specimens were not dubio- or pseudofossils, elemental mapping using energy dispersive X-ray spectroscopy (EDS) was conducted. This, in conjunction with the morphology of the specimens, indicated that the fossils were not hematite, iron sulfide, pyrolusite, or other abiologic mineral precipitates. Instead, their status as biologic structures and thus actual fossils is supported. Enrichment in the element carbon, and also possibly to some extent the elements magnesium and iron, seems to be playing some role in the preservation process.

scholarly journals Disc-shaped fossils resembling porpitids or eldonids from the early Cambrian (Series 2: Stage 4) of western USA

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3312 ◽  
Author(s):  
Bruce S. Lieberman ◽  
Richard Kurkewicz ◽  
Heather Shinogle ◽  
Julien Kimmig ◽  
Breandán Anraoi MacGabhann
Keyword(s):  
Iron Sulfide ◽  
Energy Dispersive ◽  
Early Cambrian ◽  
Elemental Mapping ◽  
Burgess Shale ◽  
X Ray ◽  
Western Usa ◽  
Element Carbon ◽  
Stage 4 ◽  
The Status

The morphology and affinities of newly discovered disc-shaped, soft-bodied fossils from the early Cambrian (Series 2: Stage 4, Dyeran) Carrara Formation are discussed. These specimens show some similarity to the OrdovicianDiscophyllumHall, 1847; traditionally this taxon had been treated as a fossil porpitid. However, recently it has instead been referred to as another clade, the eldonids, which includes the enigmaticEldoniaWalcott, 1911 that was originally described from the Cambrian Burgess Shale. The status of various Proterozoic and Phanerozoic taxa previously referred to porpitids and eldonids is also briefly considered. To help ascertain that the specimens were not dubio- or pseudofossils, elemental mapping using energy dispersive X-ray spectroscopy (EDS) was conducted. This, in conjunction with the morphology of the specimens, indicated that the fossils were not hematite, iron sulfide, pyrolusite, or other abiologic mineral precipitates. Instead, their status as biologic structures and thus actual fossils is supported. Enrichment in the element carbon, and also possibly to some extent the elements magnesium and iron, seems to be playing some role in the preservation process.

scholarly journals Palaeontology and palaeoecology of the Lower Cambrian Emu Bay Shale Lagerstätten, Kangaroo Island, South Australia

1992 ◽  
Vol 6 ◽  
pp. 221-221 ◽  
Author(s):  
Christopher Nedin
Keyword(s):  
Lower Cambrian ◽  
South Australia ◽  
Early Cambrian ◽  
Northern Coast ◽  
Body Parts ◽  
Burgess Shale ◽  
Low Oxygen ◽  
Bedding Planes ◽  
Eastern Australia ◽  
First Occurrence

The last two decades have seen the status of deposits containing soft bodied Cambrian fossils rise from geological curios into one of the foundations of modern thinking on early metazoan evolution and ecology. Some thirty of these soft bodied assemblages or Lagerstätten, resembling the Burgess Shale fauna are now known. One of these is the Lower Cambrian Emu Bay Shale fauna from Kangaroo Island, South Australia.The Emu Bay Shale has been mapped in two localities approx. 8 km (5 miles) apart on the northern coast of Kangaroo Island, at Emu Bay and at Big Gully. Previous investigations into the numerically abundant Lagerstätten fauna at Big Gully have highlighted its unusually pauperate diversity, with only some seven species described. The preservation is also unusual, comprising replacement by iron stained calcite. The fauna is confined to a 10 m thick basal siltstone. The age of the deposit is believed to be mid to upper Botomian and is thus marginally older than Early Cambrian soft bodied assemblages found on the North American continent and predating the better known Middle Cambrian Burgess Shale.In late 1991, a study of the Emu Bay Shale was undertaken to document the palaeontology and palaeoecology of the fauna. Preliminary findings, whilst increasing the number of species, confirm the pauperate diversity of the fauna. The new forms include several specimens of anomalocarid appendages. These not only represent the first occurrence of this form in Australia, but also the first occurrence outside the Burgess Shale of anomalocarid appendages with 11 segments, as compared with the more common and widespread 14 segment appendages. This connection may be important in the light of recent palaeoreconstructions which show the west coast of Canada and eastern Australia in close proximity during the early Cambrian. Also the spatial arrangement of the appendages indicates that anomalocarids may have shoaled and hunted in groups. They appear to have fed on the sea bottom, possibly using their appendages to probe the muddy bottom for shallowly buried prey as well as for capturing and transporting prey to the mouth.The assemblage appears to be dominated by the preservation of hard or permineralized body parts. However, abundant calcified ribbon-like structures concentrated on some bedding planes have yet to be classified. Several exceptionally preserved specimens of Myoscolex appear to have a series of metamerically repeated ‘paddle-like’ appendages, similar to some forms from the Burgess Shale, thus casting doubt on an annelid affinity.The assemblage appears representative of a deep water, low oxygen environment prone to periodic anoxia, possibly similar to the accretionary environment of the Burgess Shale.The Emu Bay Shale at Emu Bay exhibits a shelly assemblage, mostly comprised of disarticulated Hsuaspis exuvia with occasional small Redlichia exuvia and hyolithids. No calcite replacement is evident. The location represents current swept, probably shallow water environment.

A new study of Marrella splendens (Arthropoda, Marrellomorpha) from the Middle Cambrian Burgess Shale, British Columbia, Canada

2006 ◽  
Vol 43 (6) ◽  
pp. 721-742 ◽  
Author(s):  
Diego C García-Bellido ◽  
Desmond H Collins
Keyword(s):  
Alimentary Canal ◽  
Three Dimensional ◽  
Circulatory System ◽  
Burgess Shale ◽  
Middle Cambrian ◽  
Body Segments ◽  
Royal Ontario Museum ◽  
New Information ◽  
Shale Formation ◽  
Pair Of Antennae

Study of over 1000 specimens of Marrella splendens Walcott, 1912, out of the more than 9000 collected by the Royal Ontario Museum (ROM) since 1975, has produced new information on the anatomy, functional morphology, and behaviour of this most common arthropod in the Burgess Shale fauna. Among the new features recognized is the distinction between the alimentary canal and circulatory system; where the former is generally three-dimensional and slightly reflective, the latter never presents any relief and is very reflective. A larger range of size is now known, from 2.4 to 24.5 mm in length, with small individuals possessing 17 body segments to large specimens with more than 26 body segments, representing an almost complete ontogenetic series. The second pair of "antennae" is now interpreted as swimming appendages, since the five distal segments are dorsoventrally compressed, fringed with setae and with a considerable blood supply, providing a paddlelike appendage capable of producing a considerable propelling force. The ROM collections extend the geographical distribution of Marrella 13 km to the southeast and the stratigraphical range through the lowest five members of the Burgess Shale Formation.

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