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Pérez-Pinedo D, Nicholls R, Neville JM, McIlroy D. Hydrodynamic insights into the paleobiology of the Ediacaran rangeomorph Fractofusus misrai. iScience 2024; 27:110107. [PMID: 38947528 PMCID: PMC11214322 DOI: 10.1016/j.isci.2024.110107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 03/10/2024] [Accepted: 05/23/2024] [Indexed: 07/02/2024] Open
Abstract
The Ediacaran of Newfoundland preserves some of the oldest complex macroscopic communities, several of which are dominated by the fractal-like rangeomorph genus Fractofusus. Here we use computational fluid dynamics and a detailed reconstruction of Fractofusus misrai to document for the first time hydrodynamic phenomena associated with this sediment-reclining organism and its rangeomorph elements that are relevant to interpreting feeding strategies, explain the recently documented rheotropic growth oblique to currents, and provide insights into their impact on the Ediacaran seafloor. Obliquely oriented Fractofusus are common, likely representing a compromise between maximized aspect ratio and minimization of drag. Flow patterns on the upper surface of Fractofusus are consistent with the collection of dissolved and finely particulate nutrients, as well as gas exchange. Fractofusus produce a wake downstream, demonstrating that reclining rangeomorphs had potential to modify sedimentation patterns on the ancient seafloor by potentially allowing deposition of fine-grained sediment.
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Affiliation(s)
- Daniel Pérez-Pinedo
- Department of Earth Sciences, Memorial University of Newfoundland, St. John’s, NL A1B3X5, Canada
| | | | - Jenna M. Neville
- Department of Earth Sciences, Memorial University of Newfoundland, St. John’s, NL A1B3X5, Canada
| | - Duncan McIlroy
- Department of Earth Sciences, Memorial University of Newfoundland, St. John’s, NL A1B3X5, Canada
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Darroch SA, Gutarra S, Masaki H, Olaru A, Gibson BM, Dunn FS, Mitchell EG, Racicot RA, Burzynski G, Rahman IA. The rangeomorph Pectinifrons abyssalis: Hydrodynamic function at the dawn of animal life. iScience 2023; 26:105989. [PMID: 36756377 PMCID: PMC9900436 DOI: 10.1016/j.isci.2023.105989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/06/2022] [Accepted: 01/12/2023] [Indexed: 01/18/2023] Open
Abstract
Rangeomorphs are among the oldest putative eumetazoans known from the fossil record. Establishing how they fed is thus key to understanding the structure and function of the earliest animal ecosystems. Here, we use computational fluid dynamics to test hypothesized feeding modes for the fence-like rangeomorph Pectinifrons abyssalis, comparing this to the morphologically similar extant carnivorous sponge Chondrocladia lyra. Our results reveal complex patterns of flow around P. abyssalis unlike those previously reconstructed for any other Ediacaran taxon. Comparisons with C. lyra reveal substantial differences between the two organisms, suggesting they converged on a similar fence-like morphology for different functions. We argue that the flow patterns recovered for P. abyssalis do not support either a suspension feeding or osmotrophic feeding habit. Instead, our results indicate that rangeomorph fronds may represent organs adapted for gas exchange. If correct, this interpretation could require a dramatic reinterpretation of the oldest macroscopic animals.
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Affiliation(s)
- Simon A.F. Darroch
- Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN 37240, USA,Evolutionary Studies Institute, Vanderbilt University, Nashville, TN 37235, USA,Senckenberg Research Institute and Natural History Museum Frankfurt, 60325 Frankfurt, Germany
| | | | - Hale Masaki
- Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN 37240, USA
| | - Andrei Olaru
- Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN 37240, USA
| | - Brandt M. Gibson
- Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN 37240, USA,Department of Chemistry and Physical Sciences, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Frances S. Dunn
- Oxford University Museum of Natural History, University of Oxford, Oxford OX1 3PW, UK
| | - Emily G. Mitchell
- Department of Zoology, Museum of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK
| | - Rachel A. Racicot
- Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN 37240, USA,Evolutionary Studies Institute, Vanderbilt University, Nashville, TN 37235, USA,Senckenberg Research Institute and Natural History Museum Frankfurt, 60325 Frankfurt, Germany
| | - Gregory Burzynski
- Department of Biology, Fairfield University, Fairfield, CT 06824, USA
| | - Imran A. Rahman
- The Natural History Museum, London SW7 5BD, UK,Oxford University Museum of Natural History, University of Oxford, Oxford OX1 3PW, UK,Corresponding author
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A diverse Ediacara assemblage survived under low-oxygen conditions. Nat Commun 2022; 13:7306. [PMID: 36435820 PMCID: PMC9701187 DOI: 10.1038/s41467-022-35012-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 11/15/2022] [Indexed: 11/28/2022] Open
Abstract
The Ediacaran biota were soft-bodied organisms, many with enigmatic phylogenetic placement and ecology, living in marine environments between 574 and 539 million years ago. Some studies hypothesize a metazoan affinity and aerobic metabolism for these taxa, whereas others propose a fundamentally separate taxonomic grouping and a reliance on chemoautotrophy. To distinguish between these hypotheses and test the redox-sensitivity of Ediacaran organisms, here we present a high-resolution local and global redox dataset from carbonates that contain in situ Ediacaran fossils from Siberia. Cerium anomalies are consistently >1, indicating that local environments, where a diverse Ediacaran assemblage is preserved in situ as nodules and carbonaceous compressions, were pervasively anoxic. Additionally, δ238U values match other terminal Ediacaran sections, indicating widespread marine euxinia. These data suggest that some Ediacaran biotas were tolerant of at least intermittent anoxia, and thus had the capacity for a facultatively anaerobic lifestyle. Alternatively, these soft-bodied Ediacara organisms may have colonized the seafloor during brief oxygenation events not recorded by redox proxy data. Broad temporal correlations between carbon, sulfur, and uranium isotopes further highlight the dynamic redox landscape of Ediacaran-Cambrian evolutionary events.
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Were the First Trace Fossils Really Burrows or Could They Have Been Made by Sediment-Displacive Chemosymbiotic Organisms? Life (Basel) 2022; 12:life12020136. [PMID: 35207424 PMCID: PMC8880172 DOI: 10.3390/life12020136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/13/2022] [Accepted: 01/15/2022] [Indexed: 11/17/2022] Open
Abstract
This review asks some hard questions about what the enigmatic graphoglyptid trace fossils are, documents some of their early fossil record from the Ediacaran–Cambrian transition and explores the idea that they may not have been fossils at all. Most researchers have considered the Graphoglyptida to have had a microbial-farming mode of life similar to that proposed for the fractal Ediacaran Rangeomorpha. This begs the question “What are the Graphoglyptida if not the Rangeomorpha persevering” and if so then “What if…?”. This provocative idea has at its roots some fundamental questions about how to distinguish burrows sensu-stricto from the external molds of endobenthic sediment displacive organisms.
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Igamberdiev AU. The drawbridge of nature: Evolutionary complexification as a generation and novel interpretation of coding systems. Biosystems 2021; 207:104454. [PMID: 34126191 DOI: 10.1016/j.biosystems.2021.104454] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/07/2021] [Accepted: 06/08/2021] [Indexed: 01/25/2023]
Abstract
The phenomenon of evolutionary complexification corresponds to the generation of new coding systems (defined as а codepoiesis by Marcello Barbieri). The whole process of generating novel coding statements that substantiate organizational complexification leads to an expansion of the system that incorporates externality to support newly generated complex structures. During complexifying evolution, the values are assigned to the previously unproven statements via their encoding by using new codes or rearranging the old ones. In this perspective, living systems during evolution continuously realize the proof of Gödel's theorem. In the real physical world, this realization is grounded in the irreversible reduction of the fundamental uncertainty appearing in the self-referential process of internal measurement performed by living systems. It leads to the formation of reflexive loops that establish novel interrelations between the biosystem and the external world and provide a possibility of active anticipatory transformation of externality. We propose a metamathematical framework that can account for the underlying logic of codepoiesis, outline the basic principles of the generation of new coding systems, and describe main codepoietic events in the course of progressive biological evolution. The evolutionary complexification is viewed as a metasystem transition that results in the increase of external work by the system based on the division of labor between its components.
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Affiliation(s)
- Abir U Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John's, NL, A1B 3X9, Canada.
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Mikhailovsky G, Gordon R, Igamberdiev AU. Editorial: Symbiogenesis and progressive evolution. Biosystems 2021; 206:104429. [PMID: 33864879 DOI: 10.1016/j.biosystems.2021.104429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Richard Gordon
- Gulf Specimen Marine Laboratory, Panacea, FL, 32346, United States; C.S. Mott Center for Human Growth & Development, Department of Obstetrics & Gynecology, Wayne State University, Detroit, MI, United States.
| | - Abir U Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John's, NL, A1B 3X9, Canada.
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