Qualla: Crato Formation

Crato Formation: Introduction

Fri, 04 Sep 2026 00:00:00 GMT

Photo credit User:Thesupermat, CC BY-SA 3.0. Slide a chisel into a slab of pale limestone from a quarry near Nova Olinda and it opens like a book. On one page, a dragonfly. Not an impression of a dragonfly - the wing itself, veins and cross-veins intact, laid flat where it settled about 113 million years ago. Northeastern Brazil's Crato Formation is one of the very few places on Earth where the Cretaceous survives at this resolution. Palaeontologists call such a deposit a Lagerstätte, a mother lode, and the Crato earns the word twice over: it holds not only bones but soft tissue, gut contents, colour patterns and the wings of insects that were airborne when the dinosaurs were.

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Image: User:Thesupermat | CC BY-SA 3.0

Crato Formation: A Lake That Kept Everything

Fri, 04 Sep 2026 00:00:00 GMT

Photo credit Ghedoghedo, Public domain. The rock formed in the Araripe Basin during the latest Aptian age of the Early Cretaceous, in what is reconstructed as a semi-arid lacustrine wetland - shallow standing water in a hot, dry landscape. The bottom of that water was where things stopped. Limestone accreted around dea...

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Image: Ghedoghedo | Public domain

Crato Formation: Counting Dragonflies

Fri, 04 Sep 2026 00:00:00 GMT

Photo credit Fabin et al., 2018, CC BY 4.0. Insects are the Crato's quiet marvel. More than twenty orders are recorded, and the Odonata - dragonflies and damselflies - are unusually well represented: 384 specimens so far, 264 of them adults and 120 larvae. True bugs and grasshoppers and crickets are abundant too, in specie...

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Image: Fabin et al., 2018 | CC BY 4.0

Crato Formation: The Flying Reptiles

Fri, 04 Sep 2026 00:00:00 GMT

Photo credit MWAK, Public domain. Then there are the pterosaurs, which are the reason the Araripe Basin is known outside palaeontology. Tupandactylus, Ludodactylus, Arthurdactylus, Aymberedactylus, Lacusovagus and Brasileodactylus have all come out of these rocks, and the Crato preserves the parts of a pterosaur ...

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Image: MWAK | Public domain

Crato Formation: Naming the Rock

Fri, 04 Sep 2026 00:00:00 GMT

Photo credit Llez (H. Zell)., CC BY-SA 3.0. Fish fossils were noted in the area as early as 1823, but the Crato limestones were not methodically published until 1993, and for most of the twentieth century the unit was treated as the bottom member of the Santana Formation rather than a formation in its own right. That chang...

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Image: Llez (H. Zell). | CC BY-SA 3.0

Crato Formation: Ubirajara Goes Home

Fri, 04 Sep 2026 00:00:00 GMT

Photo credit Luxquine, CC BY-SA 4.0. Beauty has a cost here. The same slabs that split so cleanly are quarried for cement and for paving stone, and the quarrying destroys sites. Worse, the fossils are so striking that an illegal trade grew up around them, large enough to count as a local industry, and palaeontologis...

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Image: Luxquine | CC BY-SA 4.0