Spatial analyses of Ediacaran communities at Mistaken Point
Bibliographic record
Abstract
Abstract Bedding-plane assemblages of Ediacaran fossils from Mistaken Point, Newfoundland, are among the oldest known records of complex multicellular life on Earth (dated to ~565 Ma). The in situ preservation of these sessile but otherwise deeply enigmatic organisms means that statistical analyses of specimen positions can be used to illuminate their underlying ecological dynamics, including the interactions between taxa. Fossil assemblages on Mistaken Point D and E surfaces were mapped to millimeter accuracy using differentiated GPS. Spatial correlations between 10 well-defined taxa ( Bradgatia , Charniid, Charniodiscus , Fractofusus , Ivesheadiomorphs, Lobate Discs, Pectinifrons , Plumeropriscum , Hiemalora , and Thectardis ) were identified using Bayesian network inference (BNI), and then described and analyzed using spatial point-process analysis. BNI found that the E-surface community had a complex web of interactions and associations between taxa, with all but one taxon ( Thectardis ) interacting with at least one other. The unique spatial distribution of Thectardis supports previous, morphology-based arguments for its fundamentally distinct nature. BNI revealed that the D-surface community showed no interspecific interactions or associations, a pattern consistent with a homogeneous environment. On the E surface, all six of the abundant taxonomic groups ( Fractofusus , Bradgatia , Charniid, Charniodiscus , Thectardis , and Plumeropriscum ) were found to have a unique set of interactions with other taxa, reflecting a broad range of underlying ecological responses. Four instances of habitat associations were detected between taxa, of which two ( Charniodiscus – Plumeropriscum and Plumeropriscum – Fractofusus ) led to weak competition for resources. One case of preemptive competition between Charniid and Lobate Discs was detected. There were no instances of interspecific facilitation. Ivesheadiomorph interactions mirror those of Fractofusus and Charniodiscus , identifying them as a form-taxonomic grouping of degradationally homogenized taphomorphs. The absence of increased fossil abundance in proximity to these taphomorphs argues against scavenging or saprophytic behaviors dominating the E-surface community.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.003 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| 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 source (direct Gemma or distilled Codex), 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".