Pre-Columbian societies of the Llanos de Mojos engineered fisheries at landscape scale: zigzag weirs and straight causeways cross the San Joaquín floodplains, and most of the 382 detected ponds sit within 35 meters of such a feature — a system whose V-shaped structures functioned to concentrate fish as floodwater receded.

The weir/pond system description is specific and consistent with the verified zooarchaeology at AMZ-E022 and Casarabe engineering (AMZ-E014), but no dedicated evidence record is yet attached to this claim in the case file.

Verified verbatim from Blatrix et al. 2018 (Sci. Rep. 8:5998): zigzag weirs from successive V-shaped indentations; 231 of 382 ponds within 35 m of such a feature (191 of those within 35 m of a weir); "the principal function of the V-shaped structures was to concentrate fish in ponds."

Satellite imagery, hydrological surveys, and ground-truthing by Blatrix et al. (2018) documented an engineered floodplain fishery in the San Joaquín region of the Llanos de Mojos, consisting of zigzag weirs, linear causeways, and hundreds of artificial ponds situated within 35 meters of weir structures. The geometric orientation of the V-shaped weirs conclusively demonstrates a landscape-scale passive trapping system designed to concentrate fish into ponds as seasonal floodwaters receded. The strongest opposing consideration is that the exact construction chronology and labor investment required to maintain these ponds over multi-century timescales remain only partially dated.

Blatrix et al. 2018, verified, documents zigzag weirs, straight causeways, 382 ponds mostly within 35 m of such features, and proposes the fish-concentration function as floodwater receded. Strongest opposing consideration: the V-structure function is "postulated" from morphology and pond-adjacency rather than demonstrated by hydraulic reconstruction or capture evidence — a well-grounded functional inference, not a direct measurement.

No supplied evidence record states the counts of 382 ponds, their distance from weirs or causeways, or the proposed operation of the V-shaped structures. AMZ-E022 establishes year-round fishing in an engineered interfluvial landscape but does not establish this specific San Joaquín infrastructure. The strongest opposing consideration is therefore evidential absence within the permitted ledger, not a record contradicting the fishery interpretation.

The claim is anchored to Blatrix et al. 2018 in the source list, but no evidence record in the provided ledger quotes or evaluates the zigzag weirs, causeways, 382 ponds, or V-structure fishery function. Without a weighed evidence record the claim cannot be scored beyond unresolved on this run’s rules.

The Blatrix et al. 2018 source is recorded as natively fetched with the zigzag weirs, arrow-straight causeways, 382 ponds, and the fish-concentrating function of the V-shaped structures checked, and the paper's own hedge ("we postulate") is carried into the claim's wording. Convergent support for intensive interfluvial aquatic exploitation comes from AMZ-E022's zooarchaeology at a nearby mound. The strongest opposing considerations are that no dedicated evidence record was filed for this claim in the ledger — it leans on the source anchor alone — and that the functional interpretation of the V-structures is inferred from morphology and hydrology rather than demonstrated experimentally.

Rests on a verified source anchor quoting the authors' postulate that the V-shaped structures concentrated fish in ponds, with the 382 ponds and proximity finding recorded in the source verification; no separate evidence record carries it, and the source itself notes the structures concentrate fish far less intensely than modern analogues.

Held on its anchor alone: the ledger knows where the weir, causeway and pond findings are stated and has admitted no evidence record from the source; the anchored line is the authors' postulate about function. E022 on the child claim documents fish consumption, not the infrastructure.

Held on its anchor alone; no evidence record from the Blatrix paper has been admitted, so the ledger knows where the proposition is stated and not the observation behind it.

Held on its anchor alone: no admitted evidence record from the Blatrix et al. paper exists in this ledger. The proposition is what the paper states, not what the case shows.

Satellite imagery and ground survey in the Llanos de Mojos document landscape-scale fisheries consisting of zigzag weirs, causeways, and 382 ponds configured to capture fish during seasonal flood recession, verified in Blatrix et al. (2018) and corroborated by zooarchaeological analysis at Loma Salvatierra (AMZ-C026). Strongest opposing consideration: While fully described and verified in the source catalog, no standalone evidence card in evidence.yaml was linked directly to C019.

The Blatrix source is verified with the key content in the verification note (weirs, causeways, 382 ponds, the 35-meter association), though the ledger carries no dedicated evidence record for this claim. The strongest opposing consideration: the fish-concentration function is the authors' own postulate ("we postulate"), an inference from spatial patterning, not a demonstrated mechanism.

No admitted evidence record directly documents the 382 ponds, their proximity to weirs or causeways, or the proposed fish-concentrating function of the V-shaped structures. AMZ-E022 establishes year-round fishing in the wider Llanos de Mojos but does not establish this engineered floodplain system. The strongest favorable consideration is that such fishing makes the proposed function plausible, but plausibility is not evidence for the specific structures.

The Blatrix et al. 2018 source is ai-verified in the packet for zigzag weirs, straight causeways, 382 ponds mostly within 35 m of such features, and V-structures concentrating fish as floodwaters receded, matching the claim’s wording. No dedicated evidence-ledger row carries claimId AMZ-C019, which slightly lowers formal confidence relative to claims with full E-records; substance is not in serious doubt.

No evidence record in the packet carries SRC-BLATRIX-2018; the only basis is the claim's own sourceAnchor quote and the source record's verification note stating that the zigzag weirs, causeways, 382 ponds and fish-concentration function were checked on fetch. I am disclosing that basis rather than treating the claim as unsupported, since the source record is marked ai_verified with specific content, but this is materially weaker than a read evidence record. The functional interpretation ("to concentrate fish") is also explicitly a postulate in the quoted wording, and the 35-metre proximity statistic has no verified anchor in the packet at all.

Blatrix et al. (2018) document extensive zigzag weirs, causeways, and 382 ponds in the San Joaquín floodplains designed to trap and harvest fish during seasonal flood recession. The strongest opposing consideration is that while verified in the source catalog, the detailed quantitative spatial analysis lacks an expanded standalone evidence record in this specific ledger iteration.

The geometry is documented measurement: zigzag weirs, straight causeways, and 382 ponds overwhelmingly within 35 m of a feature. But the functional reading is the authors' own postulate ('we postulate that the principal function...'), so the claim's final clause asserts more than the evidence establishes; the spatial association is solid, the function inferred.

No admitted evidence record states the counts, spatial relationship, or proposed fish-concentrating function asserted in this claim. The strongest consideration against leaving it unresolved is that a verified source record and claim anchor identify the relevant study, but the assessment rules permit only evidence records to carry weight. The claim is therefore unresolved here rather than contradicted.

No evidence record in the provided ledger links to this claim or quotes the Blatrix et al. results; the source exists but is not entered as weighed evidence. Strongest opposing consideration is therefore absence of extractable support under the rules.

No evidence record is attached, so this verdict rests on the claim's own source anchor and the source record's verification note, which report zigzag weirs, straight causeways, and 382 ponds. The claim overstates its anchor on function. The authors write 'we postulate that the principal function of the V-shaped structures was to concentrate fish in ponds', which is a hypothesis, not a demonstration. The within-35-m proximity figure is not quoted anywhere in the ledger. The strongest opposing consideration is thus the gap between documented features and inferred function; the ledger gives no date for the system, and AMZ-C026's fish remains come from a different site and do not test the weirs.

Held on its source statement in Blatrix et al. 2018, with no checked evidence record taken from it. The fish-concentration function is the authors' own postulate. The Loma Salvatierra fish bones (AMZ-E022 on child C026) show fishing, not the weir system, so they give no support here.