Is the trace fossil Macaronichnus an indicator of temperate to cold waters? Exploring the paradox of its occurrence in tropical coasts
Bibliographic record
Abstract
Research Article| July 01, 2010 Is the trace fossil Macaronichnus an indicator of temperate to cold waters? Exploring the paradox of its occurrence in tropical coasts Luis I. Quiroz; Luis I. Quiroz 1Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada2Center for Tropical Paleoecology and Archaeology, Smithsonian Tropical Research Institute, Box 0843-03092, Balboa, Republic of Panama Search for other works by this author on: GSW Google Scholar Luis A. Buatois; Luis A. Buatois 1Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada Search for other works by this author on: GSW Google Scholar M. Gabriela Mángano; M. Gabriela Mángano 1Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada Search for other works by this author on: GSW Google Scholar Carlos A. Jaramillo; Carlos A. Jaramillo 2Center for Tropical Paleoecology and Archaeology, Smithsonian Tropical Research Institute, Box 0843-03092, Balboa, Republic of Panama Search for other works by this author on: GSW Google Scholar Nubia Santiago Nubia Santiago 3División Oriente, Gerencia de Exploración, PDVSA, Edificio PDVSA, Nivel Plaza, Modulo A, Ofc-54, Puerto La Cruz 6023, Venezuela Search for other works by this author on: GSW Google Scholar Author and Article Information Luis I. Quiroz 1Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada2Center for Tropical Paleoecology and Archaeology, Smithsonian Tropical Research Institute, Box 0843-03092, Balboa, Republic of Panama Luis A. Buatois 1Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada M. Gabriela Mángano 1Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada Carlos A. Jaramillo 2Center for Tropical Paleoecology and Archaeology, Smithsonian Tropical Research Institute, Box 0843-03092, Balboa, Republic of Panama Nubia Santiago 3División Oriente, Gerencia de Exploración, PDVSA, Edificio PDVSA, Nivel Plaza, Modulo A, Ofc-54, Puerto La Cruz 6023, Venezuela Publisher: Geological Society of America Received: 16 Feb 2010 Accepted: 21 Feb 2010 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2010 Geological Society of America Geology (2010) 38 (7): 651–654. https://doi.org/10.1130/G30140.1 Article history Received: 16 Feb 2010 Accepted: 21 Feb 2010 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Luis I. Quiroz, Luis A. Buatois, M. Gabriela Mángano, Carlos A. Jaramillo, Nubia Santiago; Is the trace fossil Macaronichnus an indicator of temperate to cold waters? Exploring the paradox of its occurrence in tropical coasts. Geology 2010;; 38 (7): 651–654. doi: https://doi.org/10.1130/G30140.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The trace fossil Macaronichnus is reported for the first time from low-latitude, tropical settings based on its occurrence in nearshore deposits in the Upper Oligocene–Lower Miocene Naricual Formation and in the Middle to Upper Miocene Urumaco Formation in northern Venezuela. Macaronichnus is an intrastratal trace fossil attributed to the deposit-feeding of worms in high-energy, sandy shallow-marine environments. The majority of its occurrences are from Mesozoic to Cenozoic high- to intermediate-latitude shorelines. The opheliid polychaetes Ophelia limacina and Euzonus mucronata make structures identical to those described from the fossil record in modern intertidal and shallow subtidal sediments of northwestern United States, western Canada, and Japan. Macaronichnus shows a geographical and environmental distribution in the fossil record similar to that of its modern producers and has been proposed as an indicator of high to intermediate latitudes. Accordingly, its presence in the Neogene of Venezuela is highly anomalous and seems to challenge its paleoclimatic value. However, this occurrence may be related to seasonal coastal upwelling of nutrient-rich cold waters. Such oceanographic conditions were prevalent in the northern coast of South America, at least from the Late Oligocene to the Early Pliocene prior to the final closure of the strait of Panama. This study underscores the value of Macaronichnus because its presence in the tropics may indicate upwelling conditions, providing high-resolution information in paleoceanographic reconstructions. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".