Trends of boring patterns in Paleozoic strophomenides and pentamerides from northern and eastern Canada
Bibliographic record
Abstract
Borings in shells from the Paleozoic are common in fossil assemblages, but their origins are often poorly understood. No consensus has been reached on if these borings represent predatory, parasitic or post-mortem excavations. In this study, observations were made on a large sample size of borings in strophomenides and pentamerides from Late Lochkovian, Wenlock-Ludlow, and Late Ordovician localities in northern Canada and on Anticosti Island. Multivariate statistical analyses were used to identify the origin of the borings and to describe their spatial and temporal trends.Several hundred borings in Thaerodonta-type and Strophomena-type strophomenides were identified as Oichnus simplex and Oichnus paraboloides. Borings exhibiting characteristics of predation were most common in Devonian Thaerodonta-type strophomenides and Ordovician Strophomena-type strophomenides, while parasitic and post-mortem borings were present in strophomenides of all ages. Cluster Analysis and Principal Component Analysis segregated predatory borings from non-predatory borings, and identified trends related to geologic age in Thaerodonta-type strophomenides and external shell ornamentation in Strophomena-type strophomenides. In contrast to the strophomenides, there was little evidence for predatory borings in pentamerides and multivariate analyses failed to resolve any trends. Pentamerides may have been unsuitable prey items due to their internal muscle platform structure, which made muscles unavailable to drilling predators.Borings in Paleozoic brachiopods from northern and eastern Canada represent a combination of post-mortem, parasitic and predatory behaviors, the interactions of which were complex and affected by numerous factors, such as geologic age, brachiopod shell ornamentation and internal skeletal structures. These relationships can be better understood by studying large sample sizes of borings and applying quantitative and multivariate analyses.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 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".