References

What the film claims, and where it comes from.

The film shows and doesn’t explain. Here is what stands behind each fact, for anyone who wants to check it or keep reading: the 1515 papers, the name, the rock, the Taíno and the site. Primary sources wherever they exist; where there is only one source, it says so.

Verified between July and September 2026. Archive links (PARES, USGS, Internet Archive) lead to the original documents.

The 1515 papers

All that exists of the cacique: two orders from the same day, and one from 1510 with no name.

  1. “The only place it appears is in two orders from the same day in 1515… Both call him cacique: Francisco Yamayca Araçibo.” Archivo General de Indias — PARES, call number Patronato, 175, R.1: two orders by the distributor Sancho Velázquez, Puerto Rico, March 13, 1515 (original, f.2r) and their notarial copy of December 7, 1521 (f.5r–v).Patronato,175,R.1 · f.2r l.25 «Areçabo» · f.5v l.1 «araçibo»Primary source
  2. Five years earlier, in 1510, the king ordered that his secretary be given “a very good cacique of those of the said island” — no name. Royal decree, Medinaceli, April 11, 1510, in the same file (f.1r); countersigned by Miguel Pérez de Almazán. PARESPrimary source
  3. The first time the document was printed, in 1854, it read “Aracibo.” Alejandro Tapia y Rivera, Biblioteca histórica de Puerto-Rico (1854), pp. 347–348 — Internet Archive. Reprinted in Abbad y Lasierra / Acosta (1866), pp. 93–94 — Internet Archive.Printed edition
  4. “A historian read that Yamayca as what it looks like: Jamaica.” Salvador Brau, Puerto Rico y su historia: investigaciones críticas (Valencia, 1894), ch. V, pp. 144–146 — Internet Archive: “sounding next to it the name Jamaica, the island Columbus had discovered in 1494… the cacique in that order was not a native of Boriquén.” Brau read the order in Acosta’s 1866 edition, which already printed “Jamaica”; the manuscript spells it “yamayca.”Brau 1894 · cap. V · pp. 143–148Primary source

The name

From “Aracibo” to “Arasibo,” and where “the people of the stone” came from.

  1. The spelling “Arasibo,” with an s, was fixed by Coll y Toste in 1907 so the Taíno word siba, “stone,” could be seen inside it. He glossed it “stony place.” Cayetano Coll y Toste, Prehistoria de Puerto Rico (1907) — Internet Archive (scan of the 3rd ed., 1975), vocabulary, entries “Ciba” and “Arasibo” (“siba with an s, because the Boricua did not lisp”).Primary source
  2. In 1891 Coll y Toste himself still wrote “Aracibo,” without siba. Coll y Toste, Crónicas de Arecibo (1891) — Internet Archive.Primary source
  3. “Someone wrote it on Wikipedia in the small hours of an October morning in 2021.” — The sentence “ara, possibly meaning or related to ‘people’” entered the article “Arecibo, Puerto Rico” on October 7, 2021, at 06:05 UTC. Wikipedia history — revision 1048647415en.wikipedia.org · «Added Etymology and nicknames section»Primary source
  4. “The citation it gave didn’t say that.” — The cited page, archived 22 seconds after the edit, contained only the cacique’s biographical blurb. No etymology. Wayback Machine — definitions.net, capture of Oct 7, 2021, 06:05:58 UTCPrimary source
  5. “Today you ask ChatGPT or Google’s AI, and they may well repeat the same thing: the people of the stone.” AI assistants answer from Wikipedia and its copies. The 2021 sentence now sits in Kiddle (“Ara could mean "people," and siba likely means "rock" or "stone."”), in Behind the Name (a user submission, 2024) and in Wikipedia mirrors; it is not in Simple Wikipedia, KidzSearch, Britannica Kids or EnciclopediaPR. AI answers change from day to day and query to query — which is why the film says “may.” Check it yourself: ask any assistant what Arecibo means.Verified 2026-09-20
  6. No Taíno source says ara means “people.” The Wikipedia article on the cacique has no etymology; its biographical source is a travel guide. Wikipedia — Arasibo · Spanish Wikipedia — Arecibo (the etymology section only mentions the cacique)Verified 2026-09-18
  7. What is true: siba is “stone” in Taíno. Coll y Toste (1907), entry “Ciba”; also attested as šiba in Island Carib. On what survives of the language: Julian Granberry & Gary Vescelius, Languages of the Pre-Columbian Antilles (2004).Bibliography
  8. The name, letter by letter (section “The name · letter by letter”): 1515 Areçabo · 1521 Araçibo · 1854 Aracibo · 1866 Aracibo · 1889 Areziba · 1891 Aracibo · 1894 Arazibo · 1907 Arasibo. And after: 2019 the correction to “Aracibo”; 2021 “nobody knows” (Sept 25), “arasiba = people’s stone” (Oct 7, 03:49) and “ara = people” (Oct 7, 06:05); 2024 the names dictionary; 2026 the AI. Each spelling, on its page: AGI Patronato 175, R.1, f.2r l.25 and f.5v l.1 (PARES; our own double-blind transcription) · Tapia 1854, p. 347 “Francisco Jamayca Aracibo” · Acosta 1866, p. 94 “Francisco Jamayca Aracibo” (and “Jamaica Aracibo” in his note, p. 93) · Stahl 1889, p. 67 “Areziba” · Coll y Toste 1891 “el cacique Aracibo” · Brau 1894, p. 144 “Francisco Jamaica Arazibo” · Coll y Toste 1907, vocabulary “Sitio pedregoso.—Arasibo” (the page is from the 3rd ed., 1975; the 1st is not online) · Municipality of Arecibo, “Símbolos” (“a crown symbolizing the dominion of Cacique Francisco Xalamanca Arasibo”) · Wikipedia, Nov 7, 2019, 13:50 UTC · Reddit r/etymology, Sept 25, 2021 (ref. 2.6) · Wikipedia, Oct 7, 2021, 03:49 UTC · rev. 1048647415, 06:05 UTC (ref. 2.3) · Behind the Name, Oct 16, 2024 (ref. 2.5) · the AI, Sept 20, 2026 (ref. 2.5). The site’s crops are from those same pages.Primary source

The rock

What you touch is an Ice Age dune; what holds is the Miocene.

  1. Cueva del Indio is a sea cave eroded in eolianite: a cemented sand dune, Quaternary (undated; Kaye: “earlier Pleistocene to Recent,” and the Punta Morrillos ridge line, from the end of the last glaciation or shortly after). Reginald P. Briggs, Geologic map of the Arecibo quadrangle, Puerto Rico, USGS Map I-551 (1968) — USGS (unit Qcd, “cemented dunes”) · Clifford A. Kaye, Shoreline features and Quaternary shoreline changes, Puerto Rico, USGS Professional Paper 317-B (1959), pp. 79–83 — PDF · USGS ScienceBase — Cueva del IndioPrimary source
  2. “The sea made sand out of its own dead: shells, corals, algae. The wind piled it up; water glued it back into stone.” Kaye (1959), p. 79: “shell sand… fragments of lime-secreting marine organisms, including calcareous algae”; at the base of the dunes east of Arecibo, Strombus gigas shells and coral heads. Briggs (1968): “grains chiefly calcite.”Primary source
  3. “Beneath them, beneath everything: fifteen million years.” — Under the dune, the Camuy Limestone (late Miocene) and then the Aymamón (middle Miocene) hold up the coast. Briggs (1968), units Tca and Tay · Watson H. Monroe, Geology of the middle Tertiary formations of Puerto Rico, USGS Professional Paper 953 (1980) — PDF (the Camuy is “the youngest formation of Miocene age”; the origin of the Aymamón, §Origin: a coral shallow in clear, still water, with no river input)Primary source
  4. Absolute ages of the platform: between ~15 and ~11 million years. Ortega-Ariza, Franseen, Santos-Mercado, Ramírez-Martínez & Core-Suárez, Journal of Geology 123 (2015): 539–560 — doi:10.1086/683335Peer-reviewed — figures from the abstract
  5. “Its teeth still turn up in the karst.” — Megalodon teeth in the upper Aymamón, Isabela. Nieves-Rivera, Ruiz-Yantín & Gottfried, “New record of the Lamnid shark Carcharodon megalodon from the Middle Miocene of Puerto Rico,” Caribbean Journal of Science 39(2) (2003): 223–227.Peer-reviewed
  6. Megalodon teeth found in Isabela: the local memory. February 1992: eight teeth recovered during excavations by the Isabela municipal landfill, embedded in the Aymamón Limestone (middle Miocene, ~16–11 million years); the largest ~96 mm tall by 62 wide (Nieves-Rivera et al., 2003; ref. 3.5). Outreach: Historia Borincana (Facebook) · Callejeando PR (Facebook) · Weather News PR, Dec 11, 2020. Photos on the film’s page: Weather News P.R.Local outreach
  7. “A shark eighteen meters long, three times a great white.” Maximum size estimates for megalodon (~15–18 m) against the ~6 m of a large adult great white: Wikipedia — Megalodon (with the primary literature linked).Tertiary source
  8. “The planet belonged to the apes… Today eight great apes remain.” Sergio Almécija, Ashley S. Hammond, Nathan E. Thompson, Kelsey D. Pugh, Salvador Moyà-Solà & David M. Alba, “Fossil apes and human evolution,” Science 372, eabb4363 (2021) — doi:10.1126/science.abb4363 (authors’ manuscript in the UAB repository): “With more than 50 hominoid genera and a broad geographic distribution, the Miocene has been dubbed ‘The real planet of the apes’”; and “The Miocene planet of the apes became the time of the more generalist Old World monkeys.” The eight living great apes: Wikipedia — Hominidae (humans, two chimpanzees, two gorillas, three orangutans).Bibliography
  9. “And the same sea, down there, is eating it back. Grain by grain.” Kaye (1959), p. 95: Punta Las Tunas as an example of a dune undercut by the sea (“the whole ridge trembles whenever a large wave strikes it”).Primary source
  10. Anatomy of the wall — how the dune formed: the shore elsewhere and the sea lower, the wind, rain as cement, the laminae tilted toward the sea, the pits, the loose sand beneath. Kaye (1959), §Cemented sand dunes, pp. 79–95. The cemented dunes “mark the position of former shores” (p. 82), and Kaye ties the youngest ones (generation E4, to which he assigns Punta Morrillos, the same ridge line as Punta Las Tunas) to a sea about 5 fathoms — 9 m — lower than today’s (pp. 51, 128–129, fig. 62). In a modern foredune the bedding is “a series of crossbedded wedges with all beds dipping in some degree toward the ocean (north)” (p. 82): accretion on the seaward flank. The cement “is derived from the dune itself and… is mainly precipitated from percolating rain water”; what triggers precipitation “remains to be adequately investigated” (pp. 82–83). Old dunes “tend to be better cemented than younger deposits” (p. 79). The pits: “the pits in the eolianite are due to solution by rain waters” (p. 85), plus “mechanical erosion by salt crystallization” as spray pools dry (p. 87); wastage “seems… to be largely a matter of pitting” by “chemical and organic activity” (p. 83). The ridges east of Arecibo “apparently rest on a loose sand foundation” that the surf saps (p. 95). The grains: “shell sand… fragments of lime-secreting marine organisms, including calcareous algae”; macrofossils “rare… principally… land snails” (p. 79); Briggs (1968): “grains chiefly calcite, but subordinate quartz grains are conspicuous west of the mouth of the Río Grande de Arecibo.” The site’s magnifier is a sketch, not a count; foraminifera are a normal component of Caribbean carbonate sand, not a Kaye datum for this dune. Age: Kaye, “earlier Pleistocene to Recent” (p. 79); E4 “late Wisconsin (Mankato?) or early post-Wisconsin” (p. 129); Briggs, Quaternary. The film says “Ice Age” for the mechanism; no one has dated this ridge.Primary source
  11. “Seventeen hundred meters of old sea.” — The column under the coast, from well 4CPR: Camuy 0–171 m; Aymamón 171–387; Aymamón or Aguada 387–451; Aguada 451–564; Cibao 564–870; Lares 870–1,373; San Sebastián 1,373–1,684; below, Eocene (?) volcanic rocks. The wall (eolianite, 0–25 m) is from the map: the well did not cross it. Kewanee Interamerican Oil Company test well 4CPR, “drilled near the coast (130,830 E., 72,780 N., Arecibo quadrangle) about midway between Arecibo and Barceloneta” (Monroe 1980, p. 22) — the “4CPR” symbol sits on Briggs’s (1968) map south of Punta Las Tunas, on Camuy rather than on the dune, some 500–700 m from the cave. Depths per formation after Briggs (1961), as summarized in Monroe (1980), USGS PP 953: the upper 58 m are already Camuy and the Camuy is “about 170 m” (pp. 63–64); “no samples were recovered in the interval between 122 m and 171 m” (p. 64); Aymamón 216 m (171–387 m, p. 56); 64 m “either Aymamón or Aguada” and “no samples were saved between… 433 and 451 m” (p. 50); Aguada 113 m (451–564 m, p. 50); Cibao 306 m (564–870 m, p. 41); Lares 505 m (870–1,373 m, p. 22); San Sebastián down to 1,684 m (5,527 ft, “or possibly 5,580 ft”) “of sedimentary rocks above Eocene (?) volcanic rocks,” “near what is believed to be the deepest part of the northern depositional basin” (p. 8). Eolianite thickness: Briggs (1968), unit Qcd, “0–25+ m.” Two clocks in the column: by fossils (Monroe 1980) — Camuy “may be late Miocene or even Pliocene” (p. 9), “probably upper Miocene and "its age may be as young as Pliocene"” (p. 64); Aymamón “Miocene… probably early Miocene” (p. 57), middle Miocene per Nieves-Rivera et al. (2003); Cibao and San Sebastián, Oligocene–early Miocene; and by strontium (Ortega-Ariza et al. 2015, ref. 3.4, figures from the abstract): Aguada ~14.7–11.1 Ma, Aymamón ~11 Ma at its top, Lares ~26.5–24.7 Ma, San Sebastián ~29.8–26.5 Ma. Hence “middle–late Miocene” for the Aymamón.USGS PP 953 (1980) · pp. 8, 9, 22, 41, 50, 56–57, 63–64 · Briggs 1961 · I-551 (1968)Primary source
  12. “With these shoulders. Mine.” — Section “The Miocene · the shoulders”: climbing down a tree, the chimpanzee opens its shoulder 14° more (140° vs 126°) and straightens its elbow 34° more (160° vs 126°) than climbing up; the mangabey, 4° and 3°. The authors read the ape’s mobile shoulder — which the earliest hominins kept, and from which ours comes — also as a brake for the way down, not only for hanging. Luke D. Fannin, Mary S. Joy, Nathaniel J. Dominy, W. Scott McGraw & Jeremy M. DeSilva, “Downclimbing and the evolution of ape forelimb morphologies,” Royal Society Open Science 10(9): 230145 (6 September 2023) — doi:10.1098/rsos.230145 · full text (PMC). §3.1: “Chimpanzee maximum shoulder flexion was 14° greater during bouts of downclimbing (mean: 140 ± 7° (s.e.); n = 23 bouts) than upclimbing (mean: 126 ± 4°; n = 39 bouts), and maximum elbow extension was 34° greater during bouts of downclimbing (mean: 160 ± 3°) than upclimbing (mean: 126 ± 4°)… Among mangabeys, such differences were marginal: … 4° … 3°.” Chimpanzees of Ngogo (Kibale, Uganda, 2006–2007) and mangabeys of Taï (Côte d’Ivoire, 2019 and 2022); §2: filmed “in lateral view,” angles from “three points” per joint in Kinovea/ImageJ, shoulder flexion “relative to the bole of the tree.” The eight great apes (3.8) are the Wikipedia/IUCN count; Almécija et al. count two species per genus and leave the Tapanuli as a possible subspecies. §4: “these same morphologies also speak loudly to the critical importance of controlled downclimbing”; fossil milestones: Morotopithecus (~21 Ma, “ape-like glenoid cavity”), olecranon reduction in Danuvius (12 Ma) and Hispanopithecus (10 Ma), “fully modern with the appearance of Oreopithecus (7 Ma).”Published research
  13. The section’s tree: 27 fossil genera (23 Miocene–Pleistocene apes and four of the human line — <em>Australopithecus</em>, and <em>Sahelanthropus</em>, <em>Orrorin</em> and <em>Ardipithecus</em>, “hominins or other hominines” in the figure’s legend) and the five living lineages, each in its stretch of time and with its continent. The genera, their ranges and their continents are read off figure 3 of Almécija et al. 2021 (figure caption: “the spatiotemporal ranges of the fossil hominoids mentioned in the text”; ranges measured on the figure and rounded to a tenth of a million years; point occurrences drawn as a mark; the living lineages’ bars are the tips of the figure’s tree — Pan ~0.4, Gorilla and gibbons ~0.2 — not fossil ranges). It is not the full list of the “more than 50 genera”: it is the one the authors draw. The shoulder and elbow milestones (step 2) are those cited by Fannin et al. 2023, §4; Morotopithecus sits at ~20 Ma in the figure and at “approx. 21 Ma” in Fannin et al. (the 2023 Moroto dating), hence the “some 21” in the text.Bibliography

The Taíno

Cemíes, opías, caves, and what is left of a language.

  1. “They saw the opías: the dead, coming out to eat guava in the dark.” — The watery underworld (Coaybay), caves as passage, the dead who come out at night. Fray Ramón Pané, Relación acerca de las antigüedades de los indios (c. 1498) — on the text and its editions. It is the only first-hand description of Taíno religion.Primary source (chronicle)
  2. “They did feel their cemíes in the stone.” — Cohoba, cemíes and the carved faces. Smarthistory — Taíno zemis and duhos · Wikipedia — Taíno mythologyTertiary source
  3. “Faces carved into the rock more than five hundred years ago.” — Puerto Rico’s rock art has been dated as far back as 740–400 BC. Geological Society of America — new rock-art datings (Reniel Rodríguez Ramos et al.)Published research
  4. “Of an entire language, some two hundred words remain, six sentences.” Julian Granberry & Gary Vescelius, Languages of the Pre-Columbian Antilles (University of Alabama Press, 2004) — Google Books: p. 26, “200 attested Classic Taíno language forms, most of them plant and animal names, social titles, and personal names, along with a half-dozen full sentences and approximately 1,000 analyzable toponyms”; p. 97, “six full-sentences and a number of two- or three-word phrases have survived”; the six, numbered and analyzed, on pp. 97–98.Bibliography
  5. The six sentences, each with who wrote it down (section “The language · six sentences”): “Ahiacauo guarocoel” and “Dios naboría daca” (Pané, chs. XI and XXV); “Ó cama guaxeri guariquen caona yari” and “Mayanimacaná, Juan Desquivel daca” (Las Casas, <em>Historia</em> II.3 and II.18); “Técheta cynato guamechyna” and “Guaibbá. Cynato machabuca guamechyna” (Martyr, decade III, book 8). Each one, on its page: Pané in Ulloa’s translation (Venice, 1571) — leaf 307 (“Ahiacauo Guarocoel, che vuol dire, Conosciamo questo nostro auolo”) and leaf 327 (“Dio Aboriadacha”); the same sentence in Las Casas, Apologética historia, ch. 167 (1876 ed., vol. V, pp. 521–522) · Las Casas, Historia de las Indias, book II, ch. 3 (1875 ed., vol. III, pp. 36–37) and ch. 18 (p. 127) · Peter Martyr d’Anghiera, Decades, III.8, in Joaquín Torres Asensio’s translation (Fuentes históricas sobre Colón y América, 1892, vol. II, p. 407); in English, MacNutt 1912, vol. I, p. 371. The list of the six and their morphological analysis: Granberry & Vescelius 2004, pp. 97–98 (in their order: 1 O cama…, 2 Mayani macaná…, 3 Dios naboría daca, 4 Ahiacauo guarocoel, 5 Guaibbá…, 6 Técheta…). The section’s 1–6 order is by date of the event; the translations are the chronicler’s, not G&V’s.Primary source (chronicle)
  6. The 150 words of the cloud: each is in Columbus’s log (1492–93), in Pané (c. 1498), in Martyr (1511–1530), in Oviedo (1526–1535) or in Las Casas (1527–1561), in the spelling of the edition used (for Pané, Arrom’s over Ulloa’s Italian; for Martyr, the 1892 translation), in the singular and with today’s accents where the chronicler marks the ‘long’ syllable, and almost always with its meaning beside it (“which means…”). Full texts used to check them: Las Casas, Historia de las Indias (1875–76 ed., 5 vols., Gutenberg; with the Apologética in vol. V) · Pané, José Juan Arrom’s edition (1988) and Ulloa’s Italian (1571) · Martyr, Torres Asensio’s translation (1892) · Oviedo, Historia general y natural de las Indias (1851–55 ed., 4 vols.) · Navarrete, Colección de los viages, vol. I (1825, the log of the first voyage) — all on archive.org. The glosses are the chronicler’s where he gives one, abridged; otherwise a summary of the passage. It is not Granberry & Vescelius’s list: it is the part of it you can point to on a page.Primary source (chronicle)
  7. “At dusk, bats come out of the cracks. They really do.” Direct observation during the shoot (2026). In Taíno cosmology the opías are associated with bats: Pané (c. 1498).Observation

The site

A natural and marine reserve, an archaeological site, and an access case that is still open.

  1. In September 2026 the site entered a new stage: a voluntary sale accepted by the owner, survey and appraisal under way, and the first community meeting for the management plan. Prensa sin Censura, Sep 12, 2026Press
  2. On August 11, 2026 the Arecibo court sanctioned the DRNA for failing to comply with the public-access agreement. NotiCel, Aug 11, 2026 · Ey BoricuaPress — two sources
  3. The case: a lawsuit in April 2024 over access and the management plan; an agreement with the DRNA in 2025. Marea Ecologista, Apr 9, 2024 · Primera Hora, 2025 · Latino Rebels, 2022Press
  4. Petroglyphs are being torn out of the northern caves. WAPA, Nov 26, 2025Press

Reused images and texts

What appears on screen and on this site, and under which license.

  1. The 1515 and 1521 folios. Archivo General de Indias, Patronato, 175, R.1 · Image source: Ministry of Culture (Spain) — PARES. Reuse authorized with source credit: PARES legal notice
  2. The 1968 geologic map. USGS Map I-551 (Briggs, 1968) — public domain, U.S. government. USGS Publications Warehouse
  3. The Wikipedia history. Text from Wikipedia (“Arecibo, Puerto Rico”), CC BY-SA 4.0. On screen, date and time are shown; never the username. Wikimedia — Terms of Use