Several major settlement systems were occupied into the contact era or beyond: the Belterra Plateau sites near Santarém from ca. AD 1300 to seventeenth-century European colonization (with dark earths, ponds, and trodden roads); Marajó's Cacoal site AD 1300–1650; and Upper Xingu settlements inhabited to ca. 1770 with layouts matching living Kuikuro villages.

Santarém (AMZ-E017) and Marajó (AMZ-E018) are primary-verified; the Xingu dates rest on secondary journalism (AMZ-E019) pending the primary reports, which caps confidence.

Archaeological evidence from Santarém, Marajó, and the Upper Xingu confirms that complex, engineered settlement systems persisted well into the 1500s and beyond, aligning chronologically with early European accounts. This proves that not all advanced Amazonian societies were ancient lost civilizations; some were actively functioning upon European arrival. The strongest opposing consideration is that these sustained settlements are located in optimal ecological hotspots, meaning their survival does not necessarily imply similarly dense occupation across the harsher, vastly larger terra-firme interfluves.

Stenborg et al. (2018) demonstrate Belterra sites occupied from ca. 1300 to seventeenth-century colonization with dark earths, ponds, and roads; Schaan (2000) dates Cacoal to AD 1300–1650 with clear continuity into Portuguese contact; a Science news feature reports Xingu settlements occupied to ca. 1770 with layouts matching modern Kuikuro villages. The Santarém and Marajó components are primary and strong; the Xingu piece is secondary but consistent with long established research. The main objection is reliance on journalism for the Xingu dates, but as a composite the claim is still well-supported.

Three independent contact-horizon records converge: Belterra sites from about AD 1300 to seventeenth-century colonization, with dark earths, ponds, and trodden roads (AMZ-E017, strong); Cacoal dated 1300–1650 attesting Marajoara permanence at Portuguese contact (AMZ-E018, strong); Upper Xingu settlements inhabited 500–1770 CE in layouts matching living Kuikuro villages (AMZ-E019, moderate, a news feature). These are the sites that pass the chronology filter Carvajal actually needs. Strongest opposing consideration: they are corridor and hotspot regions archaeology samples best, and the Xingu terminal dates rest on secondary reporting pending primary publication.

Belterra Plateau occupation from ca. AD 1300 to seventeenth-century colonization, with dark earths, ponds, and trodden roads, and Cacoal's AD 1300–1650 Marajoara permanence are both verified verbatim from primary papers — these are the sites that pass the contact-horizon filter. The Upper Xingu component, occupation to ~1770 in Kuikuro-pattern layouts, rests on a Science news feature, a secondary source the case itself flags as pending the primary reports. The strongest opposing consideration is that these are precisely the corridor and hotspot regions archaeology samples best, so their continuity says nothing about the interfluves — and the weakest-sourced component carries the headline continuity story. Well supported overall; moderate confidence until the Xingu primary literature replaces the journalism.

Two of the three components are anchored in primary publications verified verbatim — Belterra sites from ca. AD 1300 to seventeenth-century colonization with dark earths, ponds and trodden roads (AMZ-E017), and Cacoal at AD 1300–1650 attesting Marajoara persistence at Portuguese contact (AMZ-E018). These are the records that pass the chronological filter separating evidence about Carvajal's world from evidence about capability a millennium earlier. The strongest opposing consideration is twofold: the Upper Xingu component rests on a Science news feature rather than a primary excavation report (AMZ-E019), and all three regions are exactly the corridor and hotspot settings archaeology samples best, so continuity here says nothing about the interfluves.

Santarém and Marajó are primary-verified; the Xingu dates rest on a secondary source pending the primary reports.

Santarém (AMZ-E017) and Marajó (AMZ-E018) are primary-verified; the Xingu dates still rest on secondary reporting (AMZ-E019).

Santarém/Belterra verified verbatim (Stenborg et al. 2018); Cacoal verified verbatim (Schaan 2000, "atesta a permanência da cultura Marajoara" at Portuguese contact); the Xingu range (500–1770 CE, Kuikuro-pattern layouts) verified from a Science news feature — a secondary source, held to that weight pending the primary reports.

Direct archaeological excavations and absolute chronologies demonstrate late pre-Columbian continuity into the colonial period across several major centers, including the Belterra Plateau near Santarém (AD 1300 to seventeenth-century European colonization), the Cacoal site on Marajó Island (AD 1300–1650), and circular plaza villages in the Upper Xingu occupied up to circa 1770. These data definitively show that complex, planned settlements were not confined to the deep archaeological past but persisted up to and beyond European arrival. The strongest opposing consideration is that cultural and ceramic permanence does not preclude significant demographic thinning or structural sociopolitical transformation prior to final abandonment.

Three independent programs place major settlement systems into the contact era: Belterra Plateau to seventeenth-century colonization with dark earths, ponds, and trodden roads; Cacoal on Marajó to AD 1650; and Upper Xingu to ca. 1770 in Kuikuro-like layouts. Strongest opposing consideration: the Xingu leg rests on verified journalism summarizing unpublished primary reports, so only two legs carry primary-source weight — and none of these sites lies on Carvajal's middle Solimões route.

AMZ-E017 places numerous Belterra sites from about AD 1300 into seventeenth-century colonization, and AMZ-E018 dates Cacoal to AD 1300–1650. AMZ-E019 reports Upper Xingu occupation to about 1770 and layouts resembling modern Kuikuro villages. The strongest opposing consideration is that the Upper Xingu component comes from journalism summarizing primary research, so that part has lower evidential weight than the Belterra and Cacoal records.

Belterra Plateau sites with dark earths, ponds, and roads run ca. AD 1300 to seventeenth-century colonization (AMZ-E017); Cacoal on Marajó dates AD 1300–1650 into Portuguese contact (AMZ-E018); Upper Xingu layouts matching living Kuikuro villages extend to ca. 1770 (AMZ-E019, secondary weight). Together they establish contact-era occupation of major systems.

Two of the three legs are strongly sourced: AMZ-E017 verifies Belterra occupation from ca. AD 1300 to seventeenth-century colonization with dark earths, ponds, and trodden roads, and AMZ-E018 verifies Cacoal at 1300–1650 with explicit Marajoara cultural persistence into the Portuguese period. These are independent regions and independent research groups, which matters more than count. The strongest opposing consideration is the third leg: AMZ-E019 is a Science news feature, not a primary excavation report, so the 500–1770 CE Upper Xingu range and the Kuikuro layout continuity are held at secondary weight in the ledger's own judgement — the claim would survive its removal but with one fewer region.

AMZ-E017 (Belterra Plateau ca. AD 1300 to seventeenth-century colonization, with dark earths, ponds and trodden roads) and AMZ-E018 (Cacoal AD 1300–1650) are verbatim from primary reports; AMZ-E019 (Xingu 500–1770 CE, layouts matching Kuikuro villages) is journalism held at secondary weight pending the primary reports.

E017 (strong) dates Belterra Plateau sites AD 1300 to seventeenth-century colonization with dark earths, ponds and roads; E018 (strong) dates Cacoal AD 1300–1650; E019 (moderate, journalism) gives Xingu occupation to 1770 in layouts matching living Kuikuro villages.

E017 and E018 (strong) document Belterra to seventeenth-century colonization and Cacoal to 1650; E019 (moderate, journalism) reports Xingu settlements to 1770 in Kuikuro-like layouts.

AMZ-E017 (strong) dates Belterra Plateau sites ca. AD 1300 to seventeenth-century colonization with dark earths, ponds and trodden roads; AMZ-E018 (strong) dates Marajó's Cacoal to AD 1300–1650 into Portuguese contact; AMZ-E019 (moderate, journalism) gives Upper Xingu occupation 500–1770 CE in layouts matching living Kuikuro villages. The Xingu leg is held at secondary-source weight pending primary reports.

Archaeological dating confirms that key complex settlement systems endured into the contact era: the Belterra Plateau was occupied up to seventeenth-century European colonization with dark earths, ponds, and roads (Stenborg et al. 2018); Marajó's Cacoal site dates AD 1300–1650 (Schaan 2000); and Upper Xingu settlements were inhabited to ca. 1770 (Science/Moutinho 2024). Strongest opposing consideration: The Upper Xingu evidence is documented here via a secondary journalistic summary rather than a primary excavation monograph.

Two of the three legs are natively verified primary studies (Belterra to the seventeenth century, AMZ-E017; Cacoal AD 1300–1650, AMZ-E018); the Upper Xingu leg rests on a Science news feature (AMZ-E019) held at secondary weight. The strongest opposing consideration is that the latest-leg dates for Xingu await the primary excavation reports.

AMZ-E017 documents Belterra occupation to seventeenth-century colonization, AMZ-E018 dates Cacoal to AD 1300–1650, and AMZ-E019 reports Upper Xingu occupation to 1770 with layouts resembling modern Kuikuro villages. Together they support every regional example in the claim. The strongest opposing consideration is that the Upper Xingu evidence record is secondary science journalism rather than a primary excavation report.

Belterra Plateau sites with dark earths, ponds, and trodden roads run ca. AD 1300 into seventeenth-century colonization (AMZ-E017); Cacoal on Marajó dates AD 1300–1650 into Portuguese contact (AMZ-E018); Upper Xingu layouts matching living Kuikuro villages are reported inhabited to ca. 1770 (AMZ-E019, secondary journalism). Together they establish occupation into the contact era at multiple major systems; Xingu weight is held moderate pending primary reports.

Three independent regional programmes converge: Belterra Plateau sites dated ca. AD 1300 to seventeenth-century colonization with dark earths, ponds and trodden roads (AMZ-E017); Cacoal on Marajó at AD 1300–1650, explicitly contemporaneous with the first Portuguese settlements (AMZ-E018); and Upper Xingu settlements to 1770 CE in layouts matching living Kuikuro villages (AMZ-E019). Different regions, different teams, different site types — this is the case's best demonstration that complex settlement persisted to contact. The weakness is that AMZ-E019 is journalism summarising a research programme rather than a primary excavation report, and none of the three regions is on the middle Solimões reaches Carvajal described.

Peer-reviewed field research establishes late pre-Columbian and contact-era occupations at the Belterra Plateau near Santarém (Stenborg et al. 2018), Cacoal on Marajó (Schaan 2000), and Upper Xingu circular plaza complexes (Moutinho/Science 2024). The strongest opposing consideration is that Upper Xingu continuity is represented in the ledger primarily through secondary journalistic reporting rather than primary excavation monograph verification.

Belterra and Cacoal rest on strong primary reports with verbatim dating into the seventeenth century. The Upper Xingu leg is held at journalism weight pending primary reports, which is why confidence is moderate rather than high; nothing in the ledger opposes the occupancy chronology itself.

AMZ-E017 and AMZ-E018 directly support occupation of Belterra and Cacoal into seventeenth-century colonization, while AMZ-E019 reports Upper Xingu occupation to about 1770 and layouts matching modern Kuikuro villages. The strongest opposing consideration is that the Xingu component comes from a secondary news feature rather than the primary excavation reports. These are also distinct regional cases, so their local persistence does not establish basin-wide continuity.

Stenborg et al. (E017), Schaan (E018) and the Xingu summary (E019) independently date Belterra, Cacoal and Upper Xingu occupations into the seventeenth or eighteenth century with dark earths, roads and layout continuity. Strongest opposing consideration is that the Xingu date range rests on secondary journalism pending primary reports.

Two strong primary records carry the core. Belterra Plateau sites are dated ca. AD 1300 up to seventeenth-century colonization, with dark earths, ponds, and trodden roads (E017). Cacoal is dated AD 1300–1650, attesting Marajoara continuity while the Portuguese settled Marajó (E018). The Upper Xingu leg (inhabited 500–1770 CE in Kuikuro-like plaza layouts but ten times larger) rests on a Science news feature (E019), rightly held at secondary weight. The strongest opposing consideration is that terminal dates like 'up to the time of European colonization' are coarse, and continuity is not population size; persistence through 1542 shows these systems existed at contact, not how large they then were. These remain the ledger's key records for placing Carvajal-type societies in the contact horizon.

Three records. Belterra sites run from about AD 1300 to seventeenth-century colonization, with dark earths, ponds and roads (AMZ-E017). Cacoal runs AD 1300–1650 (AMZ-E018). Upper Xingu settlements run 500–1770 CE in Kuikuro-like layouts (AMZ-E019, a news feature held at secondary weight). The dates are sound, but all three lie on the lower Amazon and its southern tributaries, not Carvajal's middle reaches.