Ichnology of osteoderms of the pampathere Holmesina occidentalis from the Late Pleistocene / Early Holocene Tablazo Formation, Santa Elena Peninsula, Ecuador
Bibliographic record
Abstract
The first evidence of parasite-induced and scavenger-produced bioerosion is reported from large cingulates from the Late Pleistocene Coralito fauna on the Santa Elena Peninsula of Ecuador. These traces occur on the external surface of osteoderms from the large pampathere Holmesina occidentalis . Traces observed include shallow to deep amorphous etchings, shallow ovoid to hemispherical pits of various sizes ( Karethraichnus lakkos ) deep, cylindrical pits ( K. kulindros ), shallow, horizontal, gently sinuous, grooves, straight, horizontal, smooth-walled, u-shaped to rounded v-shaped grooves ( Linichnus bromleyi ) and triangular to subrounded puncture-marks ( Nihilichnus nihilicus ). Both shallow and deep ovoid to hemispherical pits are attributable to parasitic arthropods, most likely tungid fleas and ticks. The shallow and deep amorphous etchings likely record corrosion by dipteran secretions and bacterial infections. The meandering grooves may record the activity of dermestid beetle larvae. The straight grooves are interpreted to record a variety of tooth and claw scrape marks. Traces attributed in invertebrates are interpreted to record the activity of parasites, whereas the scratchmarks may have been emplaced postmortem, likely by scavengers rather than predators. Overall, parasite loads on Coralito H. occidentalis appear to have been light, with evidence of only minor scavenging of their carcasses after their death. • This paper provides the evidence of parasite-induced and scavenger-induced bioerosion on osteoderms from Holmesina occidentalis from Ecuador. • The most common traces consist of hemispherical pits and cylindrical holes that likely record the action of fleas and ticks. • Traces attributed to parasites occur dominantly on buckler osteoderms with a few on the imbricating bands. • Post-mortem invertebrate scavengers likely included dermestid beetle larvae and dipteran flies. • Traces attributed to vertebrate scavengers include rare tooth marks and claw marks.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| 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".