Sinomacrops | |
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Holotype specimen of Sinomacrops (JPM-2012-001) | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Order: | † Pterosauria |
Family: | † Anurognathidae |
Subfamily: | † Batrachognathinae |
Genus: | † Sinomacrops Wei et al., 2021 |
Type species | |
†Sinomacrops bondei Wei et al., 2021 |
Sinomacrops is a genus of extinct anurognathid pterosaur from the Middle to Late Jurassic periods of what is now the Daohugou Beds of the Tiaojishan Formation in Mutoudeng, Qinglong County of the Hebei province. The remains of Sinomacrops date back to around 164 to 158 million years ago. The type and only known species is Sinomacrops bondei. [1]
Sinomacrops derives from the Ancient Greek word roots Sino~, referring to China, macro~ (makros), meaning large, and ops, meaning eyes/face. The name Sinomacrops is in reference to both the large eyes of and the broad faces that are typical of the family Anurognathidae, as well as to the Chinese origin of the animal. The specific name, bondei, honors paleontologist Niels Bonde. [1]
Sinomacrops exhibits two autapomorphies (distinguishing traits) that distinguish it from other pterosaurs: one of them is having the first three maxillary alveoli (tooth sockets) closely spaced, and the other one is having the tibiotarsus twice as long as the femur. [1]
The holotype specimen of Sinomacrops, JPM-2012-001, consists of a crushed skeleton. The preserved bone tissue of skeleton shows a fragile, brittle condition. Due to this, in many parts of the skeleton, bone tissue fragments have been lost after the specimen was collected. These fragments that were lost left clear impressions on the matrix, which indicated their original location on the skeleton. Fragments of Sinomacrops that were lost include mainly the caudal vertebrae, the sternum, the distal (away from the point attachment) epiphysis (rounded end of a long bone) of the right humerus, proximal (near the point of attachment) epiphyses of both the right ulna and radius, parts of the left humerus, as well as most of the left manus (hand). [1]
The skeleton of Sinomacrops includes patches of soft tissue. A strange patch of soft tissue lateral (to the side) to the left tibiotarsus suggests that the brachiopatagium ("arm-membrane") extended to the rear onto the distal part of the lower leg. A brachiopatagium extending to the rear of the lower leg is also present in the species Jeholopterus ningchengensis , which is a close relative of Sinomacrops, this feature also appears in all pterosaurs in general. [1]
In its description in 2021, Wei and colleagues assigned Sinomacrops to the subfamily Batrachognathinae, a subfamily within the family Anurognathidae. Within the family, Sinomacrops was the sister taxon to the pterosaur Batrachognathus . [1] Below is a cladogram representing their phylogenetic analysis:
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. Pterosaurs are the earliest vertebrates known to have evolved powered flight. Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the ankles to a dramatically lengthened fourth finger.
Jeholopterus was a small anurognathid pterosaur known from the Middle to Late Jurassic Daohugou Beds of the Tiaojishan Formation of Inner Mongolia, China, and possibly the Early Cretaceous Sinuiju Formation of North Korea.
Dimorphodon was a genus of medium-sized pterosaur from Europe during the early Jurassic Period. It was named by paleontologist Richard Owen in 1859. Dimorphodon means "two-form tooth", derived from the Greek δι meaning "two", μορφη meaning "shape" and οδων meaning "tooth", referring to the fact that it had two distinct types of teeth in its jaws – which is comparatively rare among reptiles. The diet of Dimorphodon has been questioned among researchers, with earlier interpretations depicting it as an insectivore or a piscivore. Recent studies have suggested that Dimorphodon likely hunted small vertebrates, though it still would have consumed soft invertebrates like insects.
Anurognathus is an extinct genus of small pterosaur from the Late Jurassic Altmühltal Formation of Germany.
Batrachognathus is an extinct genus of anurognathid pterosaur from the Late Jurassic Karabastau Formation of the central Asian republic of Kazakhstan. The genus was named in 1948 by the Russian paleontologist Anatoly Nicolaevich Ryabinin. The type species is Batrachognathus volans. The genus name is derived from Greek batrakhos, "frog" and gnathos, "jaw", in reference to the short wide head. The specific epithet means "flying" in Latin.
Klamelisaurus is a genus of herbivorous sauropod dinosaur from the Middle Jurassic Shishugou Formation of China. The type species is Klamelisaurus gobiensis, which was named by Zhao Xijin in 1993, based on a partial skeleton discovered in 1982 near the abandoned town of Jiangjunmiao. Zhao described Klamelisaurus as the only member of a new subfamily, Klamelisaurinae, among the now-defunct primitive sauropod order Bothrosauropodoidea. Since Zhao's description, Klamelisaurus received limited attention from researchers until Andrew Moore and colleagues redescribed it in 2020.
Anurognathidae is a family of small, short-tailed pterosaurs that lived in Europe, Asia, and possibly North America during the Jurassic and Cretaceous periods. Five genera are known: Anurognathus, from the Late Jurassic of Germany; Jeholopterus, from the Middle to Late Jurassic of China; Dendrorhynchoides, from the Middle Jurassic of China; Batrachognathus, from the Late Jurassic of Kazakhstan; and Vesperopterylus, from the Early Cretaceous of China. Bennett (2007) suggested that the holotype of Mesadactylus, BYU 2024, a synsacrum, belonged to an anurognathid, though this affinity has been questioned by other authors. Mesadactylus is from the Late Jurassic Morrison Formation of the United States. Indeterminate anurognathid remains have also been reported from the Middle Jurassic Bakhar Svita of Mongolia and the Early Cretaceous of North Korea.
The Rhamphorhynchoidea forms one of 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 the first pterosaurs to have appeared, in the late Triassic Period. 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 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 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.
Dendrorhynchoides was a genus of anurognathid pterosaur containing only the holotype species D. curvidentatus that is known from the Middle Jurassic Tiaojishan Formation of Qinglong, northern Hebei Province, China.
The Tiaojishan Formation is a geological formation in Hebei and Liaoning, People's Republic of China, dating to the middle-late Jurassic period. It is known for its exceptionally preserved fossils, including those of plants, insects and vertebrates. It is made up mainly of pyroclastic rock interspersed with basic volcanic and sedimentary rocks. Previously, the Tiaojishan Formation was grouped together with the underlying Haifanggou Formation as a single "Lanqi Formation." The Tiaojishan Formation forms a key part of the Yanliao Biota assemblage, alongside the Haifanggou Formation.
Bellubrunnus is an extinct genus of rhamphorhynchid pterosaur from the Late Jurassic of southern Germany. It contains a single species, Bellubrunnus rothgaengeri. Bellubrunnus is distinguished from other rhamphorhynchids by its lack of long projections on the vertebrae of the tail, fewer teeth in the jaws, and wingtips that curve forward rather than sweep backward as in other pterosaurs.
Daohugoupterus is a genus of pterosaur from the Middle to Late Jurassic Daohugou Beds of the Tiaojishan Formation in Inner Mongolia, China.
Forfexopterus is a genus of ctenochasmatid pterosaur from the Early Cretaceous Jiufotang Formation in China. It contains a single species, F. jeholensis, named from a mostly complete skeleton by Shunxing Jiang and colleagues in 2016. A second specimen, consisting of a wing, was described in 2020. While the first specimen is larger, it shows signs of being less mature than the second specimen, indicating that the developmental trajectories of Forfexopterus were variable. Like other ctenochasmatids, Forfexopterus had a long, low skull filled with many slender teeth; unlike other members of the group, however, it did not have a spatula-shaped snout tip or crests, and its teeth were more curved. A single characteristic distinguishes Forfexopterus from all other members of the wider group Archaeopterodactyloidea: of the four phalanx bones in its wing finger, the first was shorter than the second but longer than the third.
Douzhanopterus is an extinct genus of monofenestratan pterosaur from the Late Jurassic of Liaoning, China. It contains a single species, D. zhengi, named by Wang et al. in 2017. In many respects, it represents a transitional form between basal pterosaurs and the more specialized pterodactyloids; for instance, its tail is intermediate in length, still being about twice the length of the femur but relatively shorter compared to that of the more basal Wukongopteridae. Other intermediate traits include the relative lengths of the neck vertebrae and the retention of two, albeit reduced, phalanx bones in the fifth digit of the foot. Phylogenetically, Douzhanopterus is nested between the wukongopterids and a juvenile pterosaur specimen from Germany known as the "Painten pro-pterodactyloid", which is similar to Douzhanopterus in many respects but approaches pterodactyloids more closely elsewhere.
Vesperopterylus is a genus of anurognathid pterosaur from the Early Cretaceous Jiufotang Formation of China, the geologically youngest member of its group. Notably, Vesperopterylus appears to have a reversed first toe, which would have been suited for gripping; it was likely arboreal, climbing or clinging to tree branches with curved, sharp claws. It also has a relatively short tail, in contrast with its tailless (Jeholopterus) and long-tailed (Dendrorhynchoides) relatives. It was first described and named by Lü Junchang et al. While the original spelling of the name was Versperopterylus, this was a typo, and was emended by the authors in accordance with the International Code of Zoological Nomenclature.
Ambopteryx is a genus of scansoriopterygid dinosaur from the Oxfordian stage of the Late Jurassic of China. It is the second dinosaur to be found with both feathers and bat-like membranous wings. Yi, the first such dinosaur, was described in 2015 and is the sister taxon to Ambopteryx. The holotype specimen is thought to be a sub-adult or adult. The specimen is estimated to have had a body length of 32 centimetres (13 in) and a weight of 306 grams (0.675 lb). The genus includes one species, Ambopteryx longibrachium.
Mimodactylus is a genus of istiodactyliform pterosaur that lived in what is now Lebanon during the Late Cretaceous, 95 million years ago. The only known specimen was discovered in a limestone quarry near the town of Hjoula, belonging to the Sannine Formation. The owner of the quarry allowed the specimen to be prepared and scientifically described by an international team of researchers, and when it was eventually sold, the buyer donated it to the MIM Museum in Beirut. In 2019, the researchers named the new genus and species Mimodactylus libanensis; the generic name refers to the MIM Museum, combined with the Greek word daktylos for "digit", and the specific name refers to Lebanon. The well-preserved holotype specimen is the first complete pterosaur from the Afro-Arabian continent, and the third pterosaur fossil known from Lebanon.
Luopterus is an extinct genus of anurognathid pterosaur containing only the holotype species L. mutoudengensis that is known from the Middle Jurassic Tiaojishan Formation of Qinglong, northern Hebei Province, China. It was originally named as a species of Dendrorhynchoides in 2012 but it was moved to the genus Luopterus in 2020. Luopterus was originally thought to be from the Early Cretaceous, with a wingspan that is about 40 centimeters (16 in), making it one of the smallest known pterosaurs.
Dearc is a genus of large-bodied rhamphorhynchine pterosaur from the Middle Jurassic Lealt Shale Formation of Scotland. The holotype, a juvenile or subadult that was still actively growing, has an estimated wingspan of 2.5 to 3 meters, making it the largest flying animal of its time. This pushes the origin of large pterosaurs back significantly, as it was previously assumed that pterosaurs did not reach greater body sizes until the short-tailed pterodactyloid lineages of the Cretaceous. The genus contains a single species, Dearc sgiathanach ( ).
Cascocauda is an extinct genus of anurognathid pterosaur from the Late–Middle Jurassic Tiaojishan Formation of Hebei Province, China. The genus contains a single species, C. rong, known from a complete skeleton belonging to a juvenile individual preserved with extensive soft-tissues, including wing membranes and a dense covering of pycnofibres. Some of these pycnofibres appear to be branched, resembling the feathers of maniraptoran theropod dinosaurs, and suggesting that pterosaur pycnofibres may be closely related to feathers in dinosaurs.