A5021373141- Paleontology and Stratigraphy of Fossils
- Geology and Paleoclimatology Research
- Marine Biology and Ecology Research
- Paleontology and Evolutionary Biology
- Geological and Geophysical Studies
- Methane Hydrates and Related Phenomena
- Evolution and Paleontology Studies
- Astro and Planetary Science
- Geological formations and processes
- Geological Studies and Exploration
- Geochemistry and Elemental Analysis
- Coral and Marine Ecosystems Studies
- Geological and Geochemical Analysis
- Marine and environmental studies
- Pleistocene-Era Hominins and Archaeology
- Geochemistry and Geologic Mapping
- Archaeology and ancient environmental studies
- Crustacean biology and ecology
- Species Distribution and Climate Change
- Ecosystem dynamics and resilience
- Marine and coastal plant biology
- Protist diversity and phylogeny
- Hydraulic Fracturing and Reservoir Analysis
- Botany, Ecology, and Taxonomy Studies
- Ecology and Vegetation Dynamics Studies
University of Toronto
2015-2024
University of Alberta
2023
Physical Sciences (United States)
2018
Vanderbilt University
2016
Continental (Canada)
2016
Northwest University
2016
University of Missouri
2016
Queen's University
2004-2016
Monash University
2016
National Museum of Natural History
2011-2013
Diverse bilaterian clades emerged apparently within a few million years during the early Cambrian, and various environmental, developmental, ecological causes have been proposed to explain this abrupt appearance. A compilation of patterns fossil molecular diversification, comparative developmental data, information on feeding strategies indicate that major animal diverged many tens millions before their first appearance in record, demonstrating macroevolutionary lag between establishment...
Shuhai Xiao, Guy M. Narbonne, Chuanming Zhou, Marc Laflamme, Dmitriy V. Grazhdankin, Malgorzata Moczydlowska-Vidal, Huan Cui. Episodes 2016;39:540-55. https://doi.org/10.18814/epiiugs/2016/v39i4/103886
The Ediacara biota include macroscopic, morphologically complex soft-bodied organisms that appear globally in the late Ediacaran Period (575-542 Ma). physiology, feeding strategies, and functional morphology of modular (rangeomorphs erniettomorphs) remain debated but are critical for understanding their ecology phylogeny. Their construction triggered numerous hypotheses concerning likely ranging from micro-to-macrophagus to photoautotrophy osmotrophy. Macrophagus rangeomorphs erniettomorphs...
The latest Neoproterozoic extinction of the Ediacara biota has been variously attributed to catastrophic removal by perturbations global geochemical cycles, 'biotic replacement' Cambrian-type ecosystem engineers, and a taphonomic artefact. We perform first critical test hypothesis using combined palaeoecological data collected from youngest Ediacaran strata in southern Namibia. find that, even after accounting for variety potential sampling biases, assemblage preserved at Farm Swartpunt...
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Abstract The mid-late Ediacaran Period (~579–541 Ma) is characterized by globally distributed marine soft-bodied organisms of unclear phylogenetic affinities colloquially called the “Ediacara biota.” Despite an absence systematic agreement, previous workers have tested for underlying factors that may control occurrence macrofossils in space and time. Three taxonomically distinct “assemblages,” termed Avalon, White Sea, Nama, were identified informally incorporated into biostratigraphy. After...
As signposted by the fossil record, early Cambrian period chronicles appearance and evolutionary diversification of most animal phyla in a geologically rapid event, traditionally termed Explosion.The uniqueness this event pleads for cause, over years, numerous biotic abiotic factors have been offered as possible triggers.Many such explanations, however, either fail to correspond time or do not provide functional mechanism explain pattern diversification.We support notion that series...
Laflamme, M., Schiffbauer, J.D., Narbonne, G.M., & Briggs, D.E.G. 2011: Microbial biofilms and the preservation of Ediacara biota. Lethaia, Vol. 44, pp. 203–213. The terminal Neoproterozoic Ediacaran Period is typified by biota (ca. 579–542 Ma), which includes first morphologically complex macroscopic organisms. Both taphonomic setting that promoted soft-bodied in coarse-grained sediments, influence associated microbial coatings on this process, have generated debate. Specimens discs...
The mid-Ediacaran Mistaken Point biota of Newfoundland represents the first morphologically complex organisms in fossil record. At classic localities is dominated by enigmatic group "fractally" branching called rangeomorphs. One few exceptions to rangeomorph body plan Thectardis avalonensis, which has been reconstructed as an upright, open cone with its apex sediment. No biological affinity suggested for this fossil, but here we show that consistent hydrodynamics sponge water-canal system....
Ediacaran fronds at Spaniard's Bay on the Avalon Peninsula of Newfoundland exhibit exquisite, three-dimensional preservation with morphological features less than 0.05 mm in width visible best preserved specimens. Most nearly 100 specimens are juvenile rangeomorphs, an extinct clade that numerically dominated early evolution complex multicellular life. rangeomorphs characterized by cm-scale architectural elements exhibiting self-similar branching over several fractal scales were used as...
This study represents a first attempt to observe soft-tissue decay in association with microbial mats, order recreate the death-mask model proposed for terminal Neoproterozoic Lagerstatten. explains precipitation of authigenic iron sulfide minerals on, and around, decaying carcasses cementing sediment as sole veneer retaining external morphology organism relief on upper lower surface coarse-grained sandy event beds. Although this has been substantiated by discovery abundant microbially...
Impressions of soft-bodied Ediacaran megafossils are common in deep-water slope deposits the June beds at Sekwi Brook Mackenzie Mountains NW Canada. Two taphonomic assemblages can be recognized. Soles turbidite contain numerous impressions simple ( Aspidella ) and tentaculate Hiemalora, Eoporpita discs. A specimen frond Primocandelabrum is attached to an -like holdfast, but most holdfast discs lack any leafy fronds which they were attached, reflecting Fermeuse-style preservation basal level...
The presumed affinities of the Terminal Neoproterozoic Ediacara biota have been much debated. However, even in absence concrete evidence for phylogenetic affinity, numerical paleoecological approaches can be effectively used to make inferences about organismal biology, nature biotic interactions, and life history. Here, we examine population structure three Ediacaran rangeomorph taxa ( Fractofusus, Beothukis, Pectinifrons ), one non-rangeomorph taxon Thectardis ) across five fossil surfaces...
The first diverse and morphologically complex macroscopic communities appear in the late Ediacaran period, 575 to 541 million years ago (Ma). enigmatic organisms that make up these are thought have formed simple ecosystems characterized by a narrow range of feeding modes, with most restricted passive absorption organic particles (osmotrophy). We test between competing models for iconic organism Tribrachidium heraldicum using computational fluid dynamics. show external morphology passively...
The Ediacaran–Cambrian transition marks one of the most important geobiological revolutions in Earth History, including multiple waves evolutionary radiation and successive episodes apparent mass extinction. Among proposed drivers these events (in particular extinction latest Neoproterozoic 'Ediacara biota') is emergence complex metazoans their associated behaviors. Many are thought to have crucial impacts on both resource availability character physical environment – 'ecosystem engineering'...
Reconstructing Precambrian eukaryotic paleoecology is pivotal to understanding the origins of modern, animal-dominated biosphere. Here, we combine new fossil data from southern Namibia with computational fluid dynamics (CFD) test between competing feeding models for Ediacaran taxon Ernietta. In addition, perform simulations multiple individuals, allowing us analyze hydrodynamics living communities. We show that Ernietta lived gregariously, forming shallow marine aggregations in latest...
The disappearance of the soft-bodied Ediacara biota at Ediacaran–Cambrian boundary potentially represents earliest mass extinction complex life, although precise driver(s) this remain unresolved. ‘biotic replacement’ model proposes that an evolutionary radiation metazoan ecosystem engineers in latest Ediacaran profoundly altered marine palaeoenvironments, resulting and setting stage for subsequent Cambrian Explosion. However, engineering across transition has yet to be quantified. Here, we...