Qualla: Itaboraí Formation https://qualla.com/itaborai-formation en-us © 2026 Bendyline Mon, 20 Jul 2026 10:21:09 GMT Qualla serial false Qualla support@bendyline.com yes https://qualla.com/_m/7/h/4/6/itaborai-formation-wp/hero-small.webp Qualla: Itaboraí Formation https://qualla.com/itaborai-formation Itaboraí Formation: Introduction https://qualla.com/itaborai-formation/ Photo credit Brazil_location_map.svg: NordNordWest derivative work: Виктор В (talk), CC BY-SA 3.0. For fifty-one years, a cement company dug limestone out of a small valley in Itaboraí, 34 kilometers northeast of Rio de Janeiro. The workers kept finding bones - fragments of animals nobody recognized, preserved in fissures in the rock where fossils had gathered over millions of years. What they were digging through is now called the Itaboraí Formation, the richest Cenozoic fossil-bearing formation in Brazil, and its contents - marsupials, flightless birds that may be ratite ancestors, crocodiles, snakes, and a species of land-dwelling mammal the size of a wolf - gave science a defining fossil unit: the Itaboraian South American Land Mammal Age. The quarry is now flooded. The fossils it produced are still being studied.

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Image: Brazil_location_map.svg: NordNordWest derivative work: Виктор В (talk) | CC BY-SA 3.0

]]> Thu, 16 Apr 2026 00:00:00 GMT https://qualla.com/_m/7/h/4/6/itaborai-formation-wp/7h46-itabora-formation-intro.mp3 0:06 1 full Itaboraí Formation: River of Beautiful Stones https://qualla.com/itaborai-formation/ Photo credit Brazil_location_map.svg: NordNordWest derivative work: Виктор В (talk), CC BY-SA 3.0. The name is Tupi, and it has two possible meanings. One derivation gives *itá* (stone), *porã* (beautiful), and *y* (river) - *river of beautiful stones*. The other substitutes *berab* (brilliant) for *porã*, giving *river of brilliant stones*. Either works; both describe what th...

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Image: Brazil_location_map.svg: NordNordWest derivative work: Виктор В (talk) | CC BY-SA 3.0

]]> Thu, 16 Apr 2026 00:00:00 GMT https://qualla.com/_m/7/h/4/6/itaborai-formation-wp/7h46-itabora-formation-river-of-beautiful-stones.mp3 0:06 2 full Itaboraí Formation: Cement Workers, Fossils https://qualla.com/itaborai-formation/ Photo credit Brazil_location_map.svg: NordNordWest derivative work: Виктор В (talk), CC BY-SA 3.0. Between 1933 and 1984, a local cement company exploited the limestones of the Itaboraí Basin for building material. As they quarried, workers noticed that the rock contained bones. The site turned out to be a series of fissure fillings - vertical cracks in the limestone that, mil...

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Image: Brazil_location_map.svg: NordNordWest derivative work: Виктор В (talk) | CC BY-SA 3.0

]]> Thu, 16 Apr 2026 00:00:00 GMT https://qualla.com/_m/7/h/4/6/itaborai-formation-wp/7h46-itabora-formation-cement-workers-fossils.mp3 0:06 3 full Itaboraí Formation: 53 Million Years Ago https://qualla.com/itaborai-formation/ Photo credit Brazil_location_map.svg: NordNordWest derivative work: Виктор В (talk), CC BY-SA 3.0. For a long time, researchers thought the Itaboraí Formation dated to the Paleocene. In 2014, a study by Woodburne and colleagues placed it more precisely in the Early Eocene, between 53 and 50 million years ago. The formation spans polarity chron 23, a recognizable magnetic inter...

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Image: Brazil_location_map.svg: NordNordWest derivative work: Виктор В (talk) | CC BY-SA 3.0

]]> Thu, 16 Apr 2026 00:00:00 GMT https://qualla.com/_m/7/h/4/6/itaborai-formation-wp/7h46-itabora-formation-53-million-years-ago.mp3 0:06 4 full Itaboraí Formation: The Itaboraian https://qualla.com/itaborai-formation/ Photo credit Brazil_location_map.svg: NordNordWest derivative work: Виктор В (talk), CC BY-SA 3.0. When paleontologists need to compare fossil faunas across continents, they use land mammal ages - regional time units defined by characteristic mammal assemblages. The Itaboraí Formation is the defining unit for the Itaboraian South American Land Mammal Age, which means that this...

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Image: Brazil_location_map.svg: NordNordWest derivative work: Виктор В (talk) | CC BY-SA 3.0

]]> Thu, 16 Apr 2026 00:00:00 GMT https://qualla.com/_m/7/h/4/6/itaborai-formation-wp/7h46-itabora-formation-the-itaboraian.mp3 0:06 5 full Itaboraí Formation: The Named and the Rare https://qualla.com/itaborai-formation/ Photo credit Brazil_location_map.svg: NordNordWest derivative work: Виктор В (talk), CC BY-SA 3.0. Several genera and species were named after the formation itself, making Itaboraí a prefix attached to an entire menagerie of extinct species: the marsupials *Itaboraidelphys camposi* and *Carolopaulacoutoia itaboraiensis*; the birds *Itaboravis elaphrocnemoides* and *Eutreptodac...

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]]> Thu, 16 Apr 2026 00:00:00 GMT https://qualla.com/_m/7/h/4/6/itaborai-formation-wp/7h46-itabora-formation-the-named-and-the-rare.mp3 0:06 6 full