Discover Brazil and Explore the Geodiversity of the Araripe UNESCO Global Geopark
- Wayne Munday
- Aug 28
- 6 min read
Updated: Sep 10
Sip back and discover Brazil and explore the heart of north east Brazil and the Araripe UNESCO Global Geopark one of the world’s most extraordinary natural landscapes. Spanning southern Ceará, northwestern Pernambuco and eastern Piauí this is one of the world’s most extraordinary geological and paleontological environments from the Lower Cretaceous. Dominated by the striking Araripe Plateau, this vast sedimentary basin formed during the breakup of Gondwana and the opening of the South Atlantic, with its limestones, sandstones, claystones and gypsum preserving a dynamic succession of ancient environments from braided rivers and lagoons to shallow coastal seas. The geopark safeguards an exceptionally diverse Lower Cretaceous fossil record with the Crato and Romualdo Formations revealing delicate plant impressions, silicified tree trunks, insects, spiders, scorpions, and aquatic species including sharks, rays, coelacanths, and bony fish, some with soft tissues remarkably intact. Amphibians, turtles, crocodilians, and dinosaurs are also represented, but the region is globally renowned for its large concentration of pterosaurs preserved with visible wing membranes and cranial crests. Beyond its fossil heritage, the plateau supports rich biodiversity at the ecological crossroads of the semi-arid Caatinga and humid gallery forests, home to endemic flora and fauna such as the endangered Araripe manakin (Chiroxiphia bokermanni). Visitors can explore nine official geosites, from fossil-rich formations to ecological hotspots, along trails, waterfalls caves, and forested paths, experiencing a rare convergence of geology, paleontology, and living ecosystems, making the Araripe Geopark a premier destination to explore the heart of northeastern Brazil.
The Araripe UNESCO Global Geopark is located within the Araripe Basin one of Brazil's largest sedimentary basins extending across southern Ceará, northwestern Pernambuco, and eastern Piauí. Rising dramatically from the plains the Araripe Plateau dominates the scenery as a striking geological feature that preserves one of the most important Lower Cretaceous fossil records on Earth dating back to between 90 - 150 million years.
The Araripe Basin formed as the ancient supercontinent Gondwana broke apart marking the early stages of the South Atlantic Ocean’s opening. Its sedimentary layers of limestones, claystones, sandstones and thick gypsum beds record a succession of environments that once shifted from shallow seas to vast lagoons and river systems.
The Araripe Basin formed during the breakup of Gondwana and the opening of the South Atlantic Ocean during the Late Jurassic to Early Cretaceous. Tectonic activity, driven by a combination of strike-slip faulting of near-vertical fractures in the Earth’s crust where rock blocks move horizontally past one another instead of vertically and normal faulting produced a system of grabens and half-grabens.
These grabens and half-grabens were gradually filled with sediments in four main stages. During an initial phase of tectonic quiescence or reduced tectonic activity during the Silurian and Devonian periods created stable conditions in the Borborema Province and allowed for the deposition of the Cariri Formation characterised as an extensively braided river systems.
During the Tithonian Stage the uppermost of the three divisions of the Upper Jurassic Series a pre-rift phase was underway and was marked the onset of lithospheric thinning and subsidence leading to the deposition of the Brejo Santo Formation’s red shales and the Missão Velha Formation noted for silicified fossil wood.
The subsequent next stage was a rift phase during the Lower Cretaceous Series between the Berriasian and Hauterivian Stage between 130 – 143.1 million years ago that saw intensified subsidence with the Abaiara Formation accumulating shales, siltstones, sandstones and conglomerates within fault-bounded basins.
Finally, the post-rift stage between the Aptian Stage the fifth of the six main subdivisions of the Lower Cretaceous Series in the Santana Group which includes the Barbalha, Crato, Ipubi and Romualdo formations. This sequence not captures a bulk of the fossils assemblages but tells as story of a dramatic environmental transition from a terrestrial continental ecosystem into a marine ecosystem represented by the fossil-rich Romualdo Formation followed by a regression that restored the continent.
The most significant fossiliferous formations are the Crato and Romualdo Formations. In the Romualdo Formation fossils are often preserved in three dimensions within limestone concretions and capture astonishing detail from insect wings to fish scales. The fossils capture the extraordinary biodiversity of Gondwana during the Early Cretaceous.
The Early Cretaceous Crato and Romualdo formations of northeastern Brazil preserve exceptionally detailed plant fossils. This Early Cretaceous Crato Formation is a limestone lagerstätte dominated by gymnosperms including conifers such as Araucariaceae, Cheirolepidiaceae, and the common Brachyphyllum, alongside a particularly rich record of Gnetales, some resembling modern tropical evergreen Gnetum. Vascular seedless plants like the fern Ruffordia goeppertii and Isoetales are also abundant. Notably, the flora includes rare Early Cretaceous angiosperms such as Araripia florifera preserved with leaves, stems, and reproductive structures, making them especially significant for understanding early flowering plant evolution. The Crato Flora not only provides critical evidence for the early radiation of angiosperms in Gondwana but also reflects a mixed riparian or river bank and semi-arid ecosystem highlighting the ecological diversity of this ancient landscape.
The Romualdo Formation, shaped by marine ingression, records terrestrial plants within coastal and marine settings and preserves primarily gymnosperm fossils notably the conifer genera Brachyphyllum and Pseudofrenelopsis. The xeromorphic traits or structural and anatomical features that helped them conserve water indicates that the Romualdo Formation experienced dry and saline conditions while marine transgressions influenced sedimentation and fossil preservation.
The Araripe UNESCO Global Geopark is renowned for its exceptional diversity of Cretaceous invertebrate fossils, particularly within the Lower Cretaceous Santana Group. The fossil assemblage includes a wide range of insects, such as dragonflies, rare moths, termites (Caatingatermes, Araripetermes and Nordestinatermes), and beetles including Protopassalus araripensis the oldest known passalid beetle.
Crustaceans are abundant, featuring shrimp species like Araripenaeus timidus, Paleomattea deliciosa, and Kellnerius jamacaruensis, alongside spinicaudatans or clam shrimp of genera such as Cyzicus, Martinestheria, and Estheriina that indicate transitional freshwater to marginal-marine conditions. Gastropods, including Tylostoma, Paraglaugonia and Pseudomesali, as well as bivalves like Brachidontes araripensis record episodes of marine incursion.
The record is further enriched by arachnids, including spiders and scorpions like Protoischnurus axelrodorum. Variation in species composition across the Santana Group reflects successive marine transgressions, with spinicaudatans marking transitional environments and decapod and bivalve assemblages indicating marine incursions.
The Araripe UNESCO Global Geopark is internationally renowned for its Early Cretaceous fish fossils exceptionally preserved in three dimensions within carbonate concretions of the Santana Formation. These fossils include over 30 species such as bony fish (Rhacolepis, Cladocyclus and Dastilbe crandalli), shark, and coelacanths (Mawsonia and Axelrodichthys). These fished lived the marine, estuary and lake ecosystems of the Araripe Basin.
The Araripe Basin also preserves an exceptionally diverse assemblage of Lower Cretaceous amphibians and reptiles found in the carbonate concretions of the Crato and Romualdo formation where again there is remarkable soft tissue preservation. Among the reptiles are turtles like Araripemys barretoi and crocodilians such as Araripesuchus. Amphibians including pipimorph frogs such as Arariphrynus are found.
Interestingly, the Araripe Basin also preserves a notable but relatively sparse record of dinosaurs from the Early Cretaceous including the recently described coelurosaur Aratasaurus museunacionali and numerous ichnites or trace fossils of dinosaur footprints dating from the Aptian Stage. Fossilised feathers from the Crato Formation provide evidence of feathered non-avian dinosaurs.
The Araripe UNESCO Global Geopark contains the largest concentration of pterosaur fossils in the world primarily found in the Romualdo Formation with specimens so well-preserved that wing membranes and head crests remain visible. The Araripe Basin has yielded exceptionally preserved specimens including notable genera such as Anhanguera, Tupandactylus (e.g., T. imperator and T. navigans), Ludodactylus and Araripedactylus. These fossils have provide critical insights into pterosaur anatomy, growth, ecology and evolutionary diversity. Alongside pterosaurs, fossils of fish, plants, and other reptiles tell a story of a coastal ecosystems of the Early Cretaceous.
The Araripe UNESCO Global Geopark is dominated by the dramatic Araripe Plateau, the region features steep escarpments, waterfalls, seasonal rivers, and rocky outcrops, reflecting the ancient environments preserved in its fossil record. Ecologically, the geopark lies at the intersection of Brazil’s semi-arid biome Caatinga biome and humid gallery forests, supporting rare endemic plants, amphibians, reptiles and birds, including the endangered Araripe manakin (Chiroxiphia bokermanni). The plateau’s geology directly shapes its ecology with cliffs providing nesting sites, springs sustaining amphibians and gypsum-rich soils nurturing specialised flora.
The geopark’s nine official geosites highlight its multifaceted heritage. Scientific sites such as Parque dos Pterossauros, Pedra Cariri and Floresta Petrificada do Cariri display fossil-rich formations and petrified forests while ecological gems like Riacho do Meio and Batateiras showcase living biodiversity. Trails along the plateau rim, forested paths, waterfalls, caves and fossil-bearing outcrops provide immersive outdoor experiences for the intrepid visitor.
