scholarly journals Morphology and ecology of the bradoriid arthropods Spinospitella and Nikolarites from the Cambrian (Series 2, Stage 4) of North Greenland (Laurentia)

PalZ ◽  
2021 ◽  
Author(s):  
John S. Peel ◽  
Christian B. Skovsted ◽  
Elise Wallet
Keyword(s):  
Ecological Control ◽  
Stage 4 ◽  
Thin Walled ◽  
North Greenland

AbstractTuberculate fragments referred to Nikolarites spasskyi are compared with a complete carapace and other material of Spinospitella from Cambrian Series 2, Stage 4 in North Greenland. The descriptions expand earlier brief records from Laurentia of the two bradoriids, originally described from Siberia and Australia, respectively. The mutually exclusive occurrences of the two taxa indicate ecological control of their distribution in North Greenland. Robust fragments of Nikolarites spasskyi occur in reworked higher energy deposits of the Aftenstjernesø Formation, while thin-walled carapaces of Spinospitella characterise deeper water mudstones within the Buen and Aftenstjernesø formations.

An outer shelf shelly fauna from Cambrian Series 2 (Stage 4) of North Greenland (Laurentia)

2021 ◽  
Vol 95 (S83) ◽  
pp. 1-41
Author(s):  
John S. Peel
Keyword(s):  
New York ◽  
New Species ◽  
North America ◽  
World Wide ◽  
Wide Distribution ◽  
East Greenland ◽  
North East ◽  
Small Shelly Fossils ◽  
Stage 4 ◽  
North Greenland

AbstractAn assemblage of 50 species of small shelly fossils is described from Cambrian Series 2 (Stage 4) strata in North Greenland, the present day northernmost part of the paleocontinent of Laurentia. The fossils are derived from the basal member of the Aftenstjernesø Formation at Navarana Fjord, northern Lauge Koch Land, a condensed unit that accumulated in a sediment-starved outer ramp setting in the transarctic Franklinian Basin, on the Innuitian margin of Laurentia. Most other small shelly fossil assemblages of similar age and composition from North America are described from the Iapetan margin of Laurentia, from North-East Greenland south to Pennsylvania. Trilobites are uncommon, but include Serrodiscus. The Australian bradoriid Spinospitella is represented by a complete shield. Obolella crassa is the only common brachiopod. Hyoliths, including Cassitella, Conotheca, Neogloborilus, and Triplicatella, are abundant and diverse, but most are represented just by opercula. Sclerites interpreted as stem-group aculiferans (sachitids) are conspicuous, including Qaleruaqia, the oldest described paleoloricate, Ocruranus?, Inughuitoconus n. gen., and Hippopharangites. Helcionelloid mollusks are diverse, but not common; they are associated with numerous specimens of the bivalve Pojetaia runnegari. The fauna compares best with that of the upper Bastion Formation of North-East Greenland, the Forteau Formation of western Newfoundland, and the Browns Pond Formation of New York, but several taxa have a world-wide distribution. Many specimens are encrusted with crystals of authigenic albite. New species: Anabarella? navaranae, Stenotheca? higginsi, Figurina? polaris, Hippopharangites groenlandicus, Inughuitoconus borealis, and Ocruranus? kangerluk.UUID: http://zoobank.org/160a17b1-3166-4fcf-9849-a3cabd1e04a3

scholarly journals A problematic cnidarian (Cambroctoconus; Octocorallia?) from the Cambrian (Series 2–3) of Laurentia

2017 ◽  
Vol 91 (5) ◽  
pp. 871-882 ◽  
Author(s):  
John S. Peel
Keyword(s):  
New Species ◽  
Fossil Record ◽  
First Record ◽  
Soft Corals ◽  
Pore System ◽  
General Development ◽  
Stage 4 ◽  
Basal Clade ◽  
The Individual ◽  
North Greenland

AbstractThe problematic calcified cnidarian Cambroctoconus is described from the Henson Gletscher Formation (Cambrian Series 2, Stage 4–Series 3, Stage 5) of North Greenland, representing the first record from Laurentia of a genus otherwise recently described from China, Kyrgyzstan, and Korea. Internal molds produced by penetrative phosphatization mirror the pervasive pore system of the calice walls and septa. The pore system is compared to the network of gastrodermal solenia that distributes nutrients between polyps and surrounding stolon tissues in present day octocorals. In conjunction with the octagonal form of the individual coralla and eight-fold symmetry of septa, the pore system promotes assignment of Cambroctoconus to the Octocorallia, a basal clade in cnidarian phylogeny. Octocorals (‘soft corals’) are diverse in present day seas, but have a poor fossil record despite the general development of distinctive calcareous spicules. New taxa: Order Cambroctoconida new; Cambroctoconus koori new species.

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.

Systematics and biogeography of some early Cambrian (Series 2) bradoriids (Arthropoda) from Laurentia (Greenland)

2017 ◽  
Vol 54 (9) ◽  
pp. 961-972 ◽  
Author(s):  
John S. Peel
Keyword(s):  
New Brunswick ◽  
Middle Latitude ◽  
Carbonate Ramp ◽  
Early Cambrian ◽  
Low Latitude ◽  
East Greenland ◽  
North East ◽  
Stage 4 ◽  
First Time ◽  
North Greenland

Bradoriid arthropods are described from the Kap Troedsson and Henson Gletscher formations of North Greenland and the Bastion Formation of North-East Greenland (Cambrian Series 2, Stage 4). Hipponicharion skovstedi n. sp. and Beyrichona avannga n. sp. represent species of genera originally described from Avalonia (New Brunswick) that are characteristic of middle-latitude assemblages in the early Cambrian. They are described for the first time from low-latitude environments in the early Cambrian of Laurentia where they occur together in a middle to upper carbonate ramp succession. Navarana n. gen. is proposed for a rare hipponicharionid currently known only from North Greenland.

Lower Cambrian (Series 2) small shelly fossils from along Nares Strait (Nunavut and Greenland; Laurentia)

2021 ◽  
pp. 495-504
Author(s):  
John S. Peel ◽  
Christian B. Skovsted
Keyword(s):  
Lower Cambrian ◽  
Ellesmere Island ◽  
Channel Formation ◽  
Inner Shelf ◽  
Nares Strait ◽  
Small Shelly Fossils ◽  
Stage 4 ◽  
Shelf Sediments ◽  
Basin Formation ◽  
North Greenland

Three small assemblages of lower Cambrian (Cambrian Series 2, Stage 4) small shelly fossils are described from Laurentian strata astride Nares Strait. The fauna from the Humboldt Formation of Daugaard-Jensen Land, North Greenland, is derived from inner shelf sediments deposited on the stable craton of the Inglefield Land High. Fossils from Judge Daly Promontory, eastern Ellesmere Island, Nunavut, occur in strata of the Cambrian Ellesmere Group (Kane Basin Formation) that have been structurally juxtaposed against older strata; they were originally assigned to the Kennedy Channel Formation, which is now considered to be of Neoproterozoic age. A similar fauna from offshore environments of the Aftenstjernesø Formation in northern Nyeboe Land, North Greenland, reflects the regional structural and sedimentological continuity with the Canadian Cambrian succession. Pojetaia robsonae sp. nov. is described from Judge Daly Promontory.

Alterations in the number of motoneurons containing immunoreactive calcitonin gene-related peptide(CGRP)& choline acetyltransferase(ChAT) in the cervical spinal cord of the wobbler mouse during the development of the motoneuron disease

1995 ◽  
Vol 53 ◽  
pp. 970-971
Author(s):  
L. Vacca-Galloway ◽  
Y.Q. Zhang ◽  
P. Bose ◽  
S.H. Zhang
Keyword(s):  
Spinal Cord ◽  
Early Stage ◽  
Cervical Spinal Cord ◽  
Wild Type Mouse ◽  
Reflex Response ◽  
Mouse Strains ◽  
Behavioral Tests ◽  
Wobbler Mouse ◽  
Stage 4 ◽  
Stage 1

The Wobbler mouse (wr) has been studied as a model for inherited human motoneuron diseases (MNDs). Using behavioral tests for forelimb power, walking, climbing, and the “clasp-like reflex” response, the progress of the MND can be categorized into early (Stage 1, age 21 days) and late (Stage 4, age 3 months) stages. Age-and sex-matched normal phenotype littermates (NFR/wr) were used as controls (Stage 0), as well as mice from two related wild-type mouse strains: NFR/N and a C57BI/6N. Using behavioral tests, we also detected pre-symptomatic Wobblers at postnatal ages 7 and 14 days. The mice were anesthetized and perfusion-fixed for immunocytochemical (ICC) of CGRP and ChAT in the spinal cord (C3 to C5).Using computerized morphomety (Vidas, Zeiss), the numbers of IR-CGRP labelled motoneurons were significantly lower in 14 day old Wobbler specimens compared with the controls (Fig. 1). The same trend was observed at 21 days (Stage 1) and 3 months (Stage 4). The IR-CGRP-containing motoneurons in the Wobbler specimens declined progressively with age.

Phosphate binders in patients with chronic kidney disease: Between the new and the old.

2019 ◽  
pp. 2-3
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Estimated Glomerular Filtration Rate ◽  
Chronic Kidney Disease Stage ◽  
Disease Stage ◽  
Phosphate Binders ◽  
Advanced Chronic Kidney Disease ◽  
Phosphate Retention ◽  
Stage 4 ◽  
Dietary Phosphate

Impaired phosphate excretion by the kidney leads to Hyperphosphatemia. It is an independent predictor of cardiovascular disease and mortality in patients with advanced chronic kidney disease (stage 4 and 5) particularly in case of dialysis. Phosphate retention develops early in chronic kidney disease (CKD) due to the reduction in the filtered phosphate load. Overt hyperphosphatemia develops when the estimated glomerular filtration rate (eGFR) falls below 25 to 40 mL/min/1.73 m2. Hyperphosphatemia is typically managed with oral phosphate binders in conjunction with dietary phosphate restriction. These drugs aim to decrease serum phosphate by binding ingested phosphorus in the gastrointestinal tract and its transformation to non-absorbable complexes [1].

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