Oligocene Shorebird Footprints, Kandi, Ombilin Basin, Sumatra
Bibliographic record
Abstract
Recent fieldwork in the Ombilin Basin of west-central Sumatra resulted in the discovery of two distinct types of avian footprints, both referable to the ichnogenus Aquatilavipes. The footprints were discovered in the Oligocene Sawahlunto Formation in a creek side outcrop near the Kandi Ombilin Mine. Aquatilavipes wallacei is a small species of Aquatilavipes (∼ 19 mm wide; 27 mm long) with elongate third digits, wide total divarication angles (120–150°) and inwardly curved peripheral digits. Aquatilavipes ichnospecies A are also small traces (average 21 mm wide; 31 mm long) with elongate third digits and straight to slightly outwardly curved peripheral digits. These traces are similar in morphology to those of small modern shorebirds such as rails (Rallidae), sandpipers (Scolapacidae) or plovers (Charadriinae). The Sawahlunto traces occur in very fine-grained to fine-grained sandstone characterized by low-relief current ripples, many of which exhibit mud-draping. A low diversity invertebrate trace fossil assemblage consisting of Arenicolites, Diplocraterion, Planolites, Monocraterion, Skolithos and Coenobichnus co-occurs with the bird footprints. This succession is interpreted as intertidal sand flats. Probe and peck marks preserved on the same bedding planes as the bird footprints support the interpretation that these birds occupied the Kandi intertidal flats for foraging purposes.
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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 | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".