Garudapterus

The Phra Prong geologic locality in the Phanom Dong Rak mountain range of Sa Kaeo Province, Eastern Thailand first attracted interest for its fossils in 2002, when the remains of sauropod dinosaurs were reported from the site. Since then, various other vertebrate remains have been discovered from the site. In 2023, part of the skull of a pterosaur was discovered at the locality alongside five teeth. It constituted the first skull remains of a pterosaur from the country, which had previously only yielded various body fossils. The locality is not assigned to any specific geological formation, but it is thought to be equivalent in age to the rocks of the Sao Khua Formation; both are part of the larger Khorat Group.^[1] An earlier 2019 study described a similar tooth from the Sao Khua Formation itself.^[1][2]

In 2025, this specimen was described by Sita Manitkoon and colleagues in the journal Cretaceous Research and named as the new taxon Garudapterus buffetauti. It is the first pterosaur to be named both from Thailand and South-East Asia as a whole, and was thus noted for its biogeographic importance. The only known specimen was catalogued in the collections of the Palaeontological Research and Education Centre at Mahasarakham University as PRC 185-190, and consists of a portion of the rostrum that includes the third through thirteenth tooth sockets, as well as five associated partial teeth. The generic name is derived from Garuda, a divine bird in Hindu and Buddhist faith, and pteron—the Latinized Greek word for "wing"—a common suffix for pterosaur names. The specific name honours Éric Buffetaut, a French palaeontologist, for his longstanding role in collaborative palaeontological work between France and Thailand.^[1]

As a gnathosaurine pterosaur, Garudapterus was a flying animal with an elongate snout ending in a spatula-like jaw tip with protruding tooth sockets holding many long teeth. The presence of two distinctive groves along its palate is a key trait identifying it as a member of the group. Compared to other gnathosaurines, it is distinguished by the shape of its snout; whereas all other species possess flattened rostrums, that of Garudapterus is keeled, forming a triangular cross-section with a raised center. The shape of the spatulate snout-tip is also unique; it is rounded in Plataleorhynchus and widest at the tip in Gnathosaurus and Tacuadactylus, but that of Garudapterus is widest in the middle, creating a diamond shape.^[1]

The tooth sockets project directly to the side of the snout, similar to the gnathosaurine Lusognathus but contrasting with the forwardly-projecting teeth of other relatives. They gradually orient downwards as they proceed towards the back of the snout, unlike Lusognathus and instead resembling the condition seen in Gnathosaurus. The sockets are slightly elliptical, being wider than tall, as are the teeth, which are more extremely oval in shape, also unlike the more circular teeth of Lusognathus. Each tooth possesses smooth enamel, similar to Lusognathus and unlike the ornamented surface seen in Tacuadactylus.^[1]

In their 2025 description of Garudapterus, Manitkoon and colleagues performed a phylogenetic analysis based on a matrix modified from a 2024 study by Rodrigo V. Pêgas, a coauthor of the Garudapterus description. Their analyses found the genus to be nested within ctenochasmatid group Gnathosaurinae, something that was also concluded from the anatomy of the fossil. Specifically, it was found to be most closely related to Lusognathus from Portugal, which shares its laterally-oriented tooth sockets. The results of their phylogenetic analysis are seen in the cladogram below:^[1]

Garudapterus fossils are known from the Phra Prong locality of the Khorat Group. This locality consists of three layers of interbedded sandstone and siltstone, with fossils found in the sandstone-dominated upper region of the second layer of the locality. Geologic study of the locality has been limited, but bivalve index fossils indicate it likely dates to the Hauterivian or Barremian age of the Early Cretaceous period. In particular, it is tentatively considered equivalent in age to the nearby Sao Khua Formation, known for its dinosaurs and other vertebrate fossils. The site where the Garudapterus holotype specimen was preserved was likely a slowly-flowing water channel, part of a larger high-energy current in an inland floodplain ecosystem. Remains of several other animals have been recovered from the site, including those of sauropod, spinosaurid and allosauroid dinosaurs, freshwater hybodonts (shark-like animals), actinopterygian fish, crocodyliform reptiles, and trionychoid, carettochelyid, and adocid turtles. Each is known from fragmentary or isolated remains, especially teeth, and thus no specific genera or species that lived alongside Garudapterus can be identified.^[1]