Paleogeographic and paleoecological significance of Schachriomonia (Brachiopoda) from the Upper Ordovician of the Tarim Basin, Northwest China
Bibliographic record
Abstract
Abstract The atrypide brachiopod Schachriomonia is documented here for the first time from the upper Katian Hadabulaktag Formation on the northeastern edge of Tarim Basin in Northwest China. These shells are conspecific with the earlier reported Rhynchotrema pentagonia Fang in Liu and Fang, 1990 from the same region. This species is most similar to Schachriomonia parva Popov et al., 1999 described from the Upper Ordovician of the Chu-Ili and Chingiz terranes and less closely resembles species from North and South China, indicating a close paleogeographic connection between these plates and terranes and Tarim during the Late Ordovician. Its dominance at three horizons in the study area may indicate that this species was an opportunistic colonizer of the seafloor following ecological disruption, or alternatively that the larvae were substrate-selective. Variation in shell shape from a nearly circular shell outline with a dorsal sulcus and ventral fold in the smallest shells to a wider outline with a more reversed dorsal fold and ventral sulcus in the largest is an example of ontogenic development. This may have been an adaptation to accommodate the growing lophophore or development of gonads in the mantle cavity over the life of the brachiopod. A stronger tooth-socket connection in larger shells strengthened the hinge area to better withstand the stresses caused by the mass of a larger shell.
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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) | 0.001 | 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) | 0.000 | 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".