The Candeleros Formation is a geologic formation that crops out in the Río Negro , Neuquén , and Mendoza provinces of northern Patagonia , Argentina . It is the oldest formation in the Neuquén Group and belongs to the Rio Limay Subgroup . Formerly that subgroup was treated as a formation, and the Candeleros Formation was known as the Candeleros Member .
10-515: Dimorphodontidae (or dimorphodontids ) is a group of early " rhamphorhynchoid " pterosaurs named after Dimorphodon , that lived in the Late Triassic to Early Jurassic . While fossils that can be definitively referred to the group are rare, dimorphodontids may have had a broad distribution, with fossils known from the UK, the southwest United States, and possibly Antarctica. Dimorphodontidae
20-704: A mix of rhamphorhynchoid and pterodactyloid features, is known from the Daohugou Beds which are most commonly dated to the Jurassic, but a few studies give a Cretaceous date. Furthermore, remains of a non-pterodactyloid from the Candeleros Formation extend the presence of basal pterosaurs into at least the early Late Cretaceous. Listing of families and superfamilies within the suborder Rhamphorhynchoidea, after Unwin 2006 unless otherwise noted. Candeleros Formation The type locality of
30-483: A replacement for Dimorphodontidae. Dimorphodontia would include all pterosaurs more closely related to Dimorphodon than to Pterodactylus . According to the analysis published by Andres et al. , Dimorphodontia is also a small group, including only Dimorphodon and Parapsicephalus . In 2018, a close relative of Dimorphodon was described from the Late Triassic of North America by Britt and colleagues, and
40-505: Is easily recognizable. The Candeleros Formation is almost 300 metres (980 ft) thick in some sections. Overall, the formation represents a part of the ancient Kokorkom desert with braided river system, made up mostly of sandstones and conglomerates . There are also isolated sections that represent eolian (wind-blown) deposition, as well as siltstones deposited under swamp conditions. Paleosols (soil deposits) are common in some sections as well. The Candeleros Formation has
50-808: The Candeleros Formation is Candeleros Hill in Neuquén Province, after which the formation was named by Wichmann in 1929. This formation unconformably overlies the Lohan Cura Formation , and it is fused with the Huincul Formation , also a unit of the Neuquén Group. The sediments of the latter are of lighter greenish and yellow colors and the fused boundary between the Candeleros and Huincul formations
60-473: The first pterosaurs to have appeared, in the late Triassic Period ( Norian age, about 210 million years ago ). Unlike their descendants, the pterodactyloids, most rhamphorhynchoids had teeth and long tails, and most species lacked a bony crest, though several are known to have crests formed from soft tissue like keratin . They were generally small, with wingspans rarely exceeding 2.5 meters, though one specimen alluded to by Alexander Stoyanow would be among
70-483: The largest pterosaurs of all time with a wingspan of 10 meters, comparable to the largest azhdarchids . However, this alleged giant Jurassic pterosaur specimen is not recorded anywhere outside the original Time article. Nearly all rhamphorhynchoids had become extinct by the end of the Jurassic Period, though some anurognathids persisted to the early Cretaceous. The family Wukongopteridae , which shows
80-741: The two suborders of pterosaurs and represents an evolutionary grade of primitive members of flying reptiles . This suborder is paraphyletic unlike the Pterodactyloidea , which arose from within the Rhamphorhynchoidea as opposed to a more distant common ancestor. Because it is not a completely natural grouping, Rhamphorhynchoidea is not used as a formal group in most scientific literature, though some pterosaur scientists continue to use it as an informal grouping in popular works, such as The Pterosaurs: From Deep Time by David Unwin, and in some formal studies. Rhamphorhynchoids were
90-643: Was named Caelestiventus . This discovery expanded the geographic, temporal and also the ecological range of dimorphodontids, as it was discovered in the Late Triassic Nugget Sandstone in Utah, which was a desert at the time. Britt and colleagues also redefined Dimorphodontidae as the least inclusive clade containing Dimorphodon macronyx and Caelestiventus hanseni . [REDACTED] [REDACTED] [REDACTED] Rhamphorhynchoidea The Rhamphorhynchoidea forms one of
100-556: Was named in 1870 by Harry Govier Seeley (as "Dimorphodontae"), with Dimorphodon as the only known member. In 2003, David Unwin defined a clade Dimorphodontidae, as the group consisting of the last common ancestor of Dimorphodon macronyx and Peteinosaurus zambellii , and all its descendants. However, later studies found that Dimorphodon may not be closely related to Peteinosaurus , so this definition of Dimorphodontidae would therefore be superfluous. In 2014, Brian Andres and colleagues defined another clade, Dimorphodontia , as
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