Composite ichnological-pathological evidence for arthropod parasitism on osteoderms of Boreostemma acostae (Glyptodontidae, Cingulata) from La Venta, Colombia
Bibliographic record
Abstract
The first evidence of parasite-induced bioerosion is reported from large cingulates from the Middle Miocene La Venta fauna of Colombia. These traces occur primarily on osteoderms in the anterior caudal armor of the moderate-sized glyptodontine Boreostemma acostae . The traces are small (∼3–3.5 mm wide), cylindrical, non-penetrative holes (∼4.5 mm deep) on the external surface of osteoderms that most commonly occur at epidermal sulci or at triple junctions between three osteoderms. These traces are most morphologically similar to the ichnotaxon Karethraichnus kulindros ; however, forms similar to K. zaratan and K. minimum also occur. Dense bone on the hole margins indicates that these features comprise compound trace fossils and pathologies. It is postulated that these traces were emplaced by fleas similar to the modern malacopsyllid flea taxon, Tunga perforans which emplace similar, but not identical holes, in modern armadillo osteoderms. The La Venta traces extend the range of purported hectopsyllid flea traces to the Middle Miocene of Colombia. To date, traces attributable to hectopsyllid fleas have been observed on Oligocene to Pleistocene/Early Holocene glyptodontids and Late Miocene to present-day armadillos. The La Venta Boreostemma traces support the hypothesis that the tick-cingulate relationship was initiated on glyptodontids, subsequently moving to armadillos later in the Neogene. • The first evidence of parasite-induced bioerosion on Middle Miocene Boreostemma acostae is presented. • The traces consist of cylindrical holes with dense margins, indicating that they are composite trace fossils-pathologies. • These traces are atrtibuted to fleas similar to the modern malacopsyllid flea taxon, Tunga perforans . • The La Venta traces extend the range of purported hectopsyllid flea traces to the Middle Miocene of Colombia. • These traces support the hypothesis that the tick parasitism started on glyptodontids, later moving to armadillos.
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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 | 0.001 |
| Science and technology studies | 0.000 | 0.005 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".