''Tacuadactylus'' is a genus of ctenochasmatid

pterosaur Pterosaurs are an extinct clade of flying reptiles in the order Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 million to 66 million years ago). Pterosaurs are the earli ...

from the

Late Jurassic The Late Jurassic is the third Epoch (geology), epoch of the Jurassic Period, and it spans the geologic time scale, geologic time from 161.5 ± 1.0 to 143.1 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic stratum, strata.Owen ...

Uruguay Uruguay, officially the Oriental Republic of Uruguay, is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast, while bordering the Río de la Plata to the south and the A ...

Discovery and naming

A snout found near Batoví was in 2016 reported as a saw fish, the oldest known member of the

Pristidae Sawfish, also known as carpenter sharks, are a Family (biology), family of very large batoidea, rays characterized by a long, narrow, flattened rostrum (anatomy), rostrum, or nose extension, lined with sharp transverse plane, transverse teeth, ...

. Subsequently, a

CAT-scan A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...

showed that the presumed perpendicular teeth of the fossil were in fact sediment fillings of the tooth sockets, which themselves pointed obliquely to the front as with pterosaurs. In 2018, the specimen was described as the first pterosaur found in Uruguay but not yet named.Daniel Perea, Matías Soto, Pablo Toriño, Valeria Mesa & John G. Maisey, (2018), "A Late Jurassic-?earliest Cretaceous ctenochasmatid (Pterosauria, Pterodactyloidea): The first report of pterosaurs from Uruguay", ''Journal of South American Earth Sciences'' 85: 298-306 In 2021, the

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

''Tacuadactylus luciae'' was named and described by Matías Soto, Felipe Montenegro, Pablo Toriño, Valeria Mesa and Daniel Perea. The generic name combines a reference to the location of the discovery with a Greek ''daktylos'', "finger", a usual suffix in the names of pterosaurs. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

honours Soto's daughter, Lucia. The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

, FC-DPV-2869, was recovered from rocks in the Batoví Member of the lower Tacuarembó Formation. It consists of fragments of the

rostrum Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit ** podium * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ...

and dentary. Other remains are six loose teeth, specimen FC-DPV 3090, found at Bidegain in the same formation.

Classification

''Tacuadactylus'' is a member of the Gnathosaurinae, and closely related to ''

Gnathosaurus ''Gnathosaurus'' (meaning "jawed lizard") is a genus of ctenochasmatid pterosaur containing two species: ''G. subulatus'', named in 1833 from the Solnhofen Limestone of Germany, and ''G. macrurus'', known from the Purbeck Limestone of the UK. ...

''. It was in 2021 the oldest known ctenochasmatid from South America. Below is a cladogram from a 2025 study by Sita Maritkoon and colleagues, reaffirming its close relation to ''Gnathosaurus'':

References

{{Portal bar, Paleontology, Uruguay Jurassic pterosaurs of South America Jurassic Uruguay Fossils of Uruguay Tacuarembó Formation Fossil taxa described in 2021 Ctenochasmatoids