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Below are 19 entries, after skipping 40 most recent ones in the "Сообщество, посвящённое ра" journal:| May 28th, 2014 | |
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| 03:33 pm [industrialterro] [Link] |
Feilongus Feilongus is an extinct genus of ctenochasmatoid or ornithocheiroid pterodactyloid pterosaur from the Barremian-Aptian-age Lower Cretaceous Yixian Formation of Beipiao, Liaoning, China. The genus was named in 2005 by Wang Xiaolin e.a.. The type species is Feilongus youngi. The genus name is derived from Feilong, the "flying dragon". The specific name honours the late Chinese paleontologist Yang Zhongjian or "Chung Chien Young". Feilongus is based on holotype IVPP V-12539, a skull and articulated mandible, with on the same plate the detached posterior braincase, of a subadult individual. The fossil is strongly crushed. It is notable for having two bony crests on the skull (one long and low on middle of the snout, and one projecting backwards from the rear of the skull), and for the upper jaws being 10% or 27 millimetres longer than the lower jaws, giving it a pronounced overbite. The preserved part of the second crest was short with the leading edge rounded, and may have had a nonbony extension, now lost. The skull of the only known individual is 390-400 millimeters long (15.4-15.7 inches) and extremely elongated with a slightly concave top. Its wingspan was estimated by Wang to have been around 2.4 meters (7.9 feet), making it large for a basal pterodactyloid. The skull and lower jaws held 76 long, curved needle-like teeth, eighteen in the upper, nineteen in the lower jaw, confined to the beak ends, the anterior third, of the jaws. A cladistic analysis by the describers showed Feilongus as the sister taxon of a clade consisting of Gallodactylus and Cycnorhamphus, meaning it was a member of the Gallodactylidae sensu Kellner, a group of ctenochasmatoids, within the larger Archaeopterodactyloidea, the clade containing according to Alexander Kellner the most basal pterodactyloids. The Ctenochasmatoidea are known for having numerous small, thin teeth, possibly for straining food from water, as flamingos do today. However, in 2006 an analysis by Lü Junchang had as outcome that Feilongus was not an archaeopterodactyloid, but a member of the Ornithocheiroidea sensu Kellner, closer to the Anhangueridae. This means that using the alternative terminology of David Unwin they are close to the Ornithocheiroidea sensu Unwin, a group the members of which are typically more adapted to soaring and a piscivore, or fish-eating, diet. Another publication following this general line of thought has put Feilongus and Boreopterus into a new ornithocheiroid family, the Boreopteridae. В Ляонине, северо-восточной области Китая, палеонтологи обнаружили окаменелости двух новых видов птерозавров. Feilongus youngi и Nurhachius ignaciobritoi разделяли небеса с ранними птицами 120 миллионов лет назад. Tags: Вымершие рептилии, Мел, авеметатарзалии, архозавроморфы, архозавры, диапсиды, ктенохазматоидеи, монофенестраты, птеродактили, птерозавры |
| May 22nd, 2014 | |
| 01:19 pm [industrialterro] [Link] |
Eopteranodon Eopteranodon (meaning "dawn Pteranodon (toothless wing)") is a genus of azhdarchoid pterodactyloid pterosaur from the Aptian-age Lower Cretaceous Yixian Formation of Beipaio City, Liaoning, China. The genus was in 2005 named by Lü Junchang and Xang Xingliao. The type species is Eopteranodon lii. It is based on the type specimen or holotype BPV-078, an incomplete skeleton and skull. Its skull, including a large crest, was toothless and similar to that of Pteranodon. The skull lacks the point of the snout but it was in life less than 200 millimeters long (7.9 inches), and the animal had a wingspan of about 1.1 meters (3.6 feet). A second specimen, D2526, described in 2006, had a larger wingspan. Despite its similarities to Pteranodon, Eopteranodon was not placed into a family by its describers, who put it into the clade Pteranodontia as incertae sedis (uncertain position). Shortly thereafter, a phylogenetic study of all known Yixian pterosaurs by the same scientists found it to be close to the azhdarchoids, noted for the crested genera Tapejara and Tupuxuara, and the giant, long-necked Quetzalcoatlus. A further analysis of other recently discovered forms, in 2006 still considered basal to (having split off earlier than) azhdarchoids, helped the original authors, along with David Unwin, to place these species together with Eopteranodon in a new clade Chaoyangopteridae, the possible sister group of the Azhdarchidae. The Chaoyangopteridae are a family of pterosaurs within the Azhdarchoidea. The clade Chaoyangopteridae was first defined in 2008 by Lü Junchang and David Unwin as: "Chaoyangopterus, Shenzhoupterus, their most recent common ancestor and all taxa more closely related to this clade than to Tapejara, Tupuxuara or Quetzalcoatlus". Based on neck and limb proportions, it has been suggested they occupied a similar ecological niche to that of azhdarchid pterosaurs, though it is possible they were more specialised as several genera occur in Liaoning, while azhdarchids usually occur by one genus in a specific location. The Chaoyangopteridae are mostly known from Asia, though the possible member Lacusovagus occurs in South America and there are possible fossil remains from Africa. Tags: Вымершие рептилии, Мел, авеметатарзалии, аждархойды, архозавроморфы, архозавры, диапсиды, монофенестраты, орнитохейройды, птеродактили, птерозавры, чаоянгоптериды |
| 11:49 am [industrialterro] [Link] |
Dsungaripterus Dsungaripterus was a genus of pterosaur, with an average wingspan of 3 metres (9.8 ft). It lived during the Early Cretaceous, in China, where the first fossil was found in the Junggar Basin. Dsungaripterus was in 1964 named by Yang Zhongjian. The genus name combines a reference to the Junggar Basin with a Latinized Greek pteron, "wing". The type species is Dsungaripterus weii, the specific name honouring paleontologist C.M. Wei of the Palaeontological Division, Institute of Science, Bureau of Petroleum of Sinkiang. The holotype is IVPP No. V-2776, a partial skull and skeleton. From 1973 more material has been found including almost complete skulls. In 1980 Peter Galton renamed Pterodactylus brancai (Reck 1931), a form from a late Jurassic African formation, into Dsungaripterus brancai, but the identification is now commonly rejected. In 1982 Natasha Bakhurina named a Dsungaripterus parvus based on a smaller skeleton from Mongolia. Later this was renamed into "Phobetor", a preoccupied name, and in 2009 concluded to be identical to Noripterus. In 2002 a Dsungaripterus wing finger phalanx was reported from Korea. Dsungaripterus weii had a wing span of 3 to 3.5 metres (9.8-11.5 ft). Its skull, forty to fifty centimetres long, bore a low bone crest that ran down from the base of the skull to halfway to the beak. Dsungaripterus's head and neck were together almost a meter long. Its most notable feature are its long, narrow, upcurved jaws with a pointed tip, making the animal look like a pair of flying tweezers. It had no teeth in the front part of its jaws, which were probably used to remove shellfish and worms from cracks in rocks or/and the sandy, muddy beaches it inhabited. It had knobbly flat teeth more to the back of the jaw that were well suited for crushing the armor of shellfish. Dsungaripterus was by Yang classified as a member of the Dsungaripteridae. Репродукции (1, 2, 3, 4, 5, 6, 7, 8, 9): ( Read More ) Ископаемые останки (1, 2, 3, 4): Tags: Вымершие рептилии, Мел, авеметатарзалии, аждархойды, архозавроморфы, архозавры, джунгариптероиды, диапсиды, монофенестраты, орнитохейройды, птеродактили, птерозавры |
| May 17th, 2014 | |
| 03:38 pm [industrialterro] [Link] |
Domeykodactylus Domeykodactylus was a genus of dsungaripteroid pterodactyloid pterosaur from the Early Cretaceous-age Quebrada de la Carreta of Antofagasta, Chile. The genus was named in 2000 by David Martill, Eberhard Frey, Guillermo Chong Diaz and Charles Michael Bell. The type species is Domeykodactylus ceciliae. The genus name is derived from the Cordillera Domeyko and Greek daktylos, "finger" in reference to the wing finger typical of pterosaurs. The specific name honours geologist Cecilia Demargasso of the Universidad Católica del Norte, "who was so kind to us". Domeykodactylus is based on holotype Departmento de Ciencias Geológicas at the Universidad Católica del Norte, Antofagasta 250973, found in the Sierra da Candeleros. It consists of a partial mandible; a premaxilla, present in the same rock, is referred to it as paratype. The fossil had at first been thought to belong to Pterodaustro. Domeykodactylus had a crest running along the top of the premaxilla. The bone structure of the crest consists of vertical trabeculae, narrow struts; it was this texture that had originally been mistaken for the fine filter teeth of Pterodaustro. The mandible has a short symphysis. There are sixteen tooth sockets, from which the teeth themselves have been lost, in each dentary. The sockets are narrow, oval and slightly elevated, with a raised margin, above the level of the jaw. The teeth were probably small and towards the back more widely spaced and declining in size. The skull length has been estimated at thirty centimetres and the wingspan at one metre (3.28 ft). The describers found Domeykodactylus similar to both the Ctenochasmatidae and Dsungaripteridae in the crest; because of the elevated tooth sockets it was assigned to the latter group. It was the first published example of a dsungapterid in South America, most other members of the family being from Asia.
Tags: Вымершие рептилии, Мел, авеметатарзалии, аждархойды, архозавроморфы, архозавры, джунгариптероиды, диапсиды, монофенестраты, орнитохейройды, птеродактили, птерозавры |
| May 8th, 2014 | |
| 08:46 pm [industrialterro] [Link] |
Coloborhynchus Coloborhynchus is a genus in the pterosaur family Ornithocheiridae, and is known from the Lower Cretaceous of England (Albian age, 98 million years ago), and possibly the Aptian age (112-99 million years ago) of Brazil and Texas, depending on which species are included. The type specimen of Coloborhynchus is known only from a partial upper jaw. Therefore, according to Rodrigues and Kellner's 2008 re-evaluation on Coloborhynchus clavirostris, it can only be differentiated from its relatives based on its unique combination of tooth socket positions. In Coloborhynchus, the two front teeth pointed forward and were higher on the jaw than the other teeth, while the next three pairs of teeth pointed to the sides. The final two (preserved) pairs of teeth pointed downward. Finally, a unique oval depression was located below the first pair of teeth. Like the related Anhanguera and Uktenadactylus, the tip of the snout flared out into a wider rosette, in contrast to the narrow posterior jaws. However, whereas the rosettes of species typically assigned to Anhanguera were rounded and spoon-shaped, those of Сoloborhynchus were robust and box-shaped. Also like its close relatives, Coloborhynchus had a keel-shaped crest on the front of its jaws, though it was broad and thinned from base to top, rather than the uniformly thin crests of its relatives. This kind of thickened crest is also seen in Siroccopteryx moroccensis, which may be its closest relative or a member of the same genus. It also had a straight, rather than curved, front margin, unlike its relatives, and begins at the tip of the snout, rather than further back as in other species. A second specimen showing all of these same unique features was reported to Brazilian paleontologist Alexander Kellner by Darren Naish in 2007, and likely represents a second specimen of C. clavirostris, though it has not yet been described. The possible species Coloborhynchus capito represents the largest known ornithocheirid, and indeed the largest toothed pterosaur known. A referred specimen from the Cambridge Greensand of England described in 2011 consists of a very large upper jaw tip which displays the tooth characteristics that distinguish C. capito from other species. The jaw tip is nearly 10 cm tall and 5.6 cm wide, with teeth up to 1.3 cm in base diameter. If the proportions of this specimen were consistent with other known species of Coloborhycnhus, the total skull length could have been up to 75 cm, leading to an estimated wingspan of 7 metres (23 ft). Like many ornithocheiroid pterosaurs named during the 19th century, Coloborhynchus has a highly convoluted history of classification. Over the years numerous species have been assigned to it, and often, species have been shuffled between Coloborhynchus and related genera by various researchers. In 1874 Richard Owen, rejecting the creation by Harry Govier Seeley of the genus Ornithocheirus, named a species Coloborhynchus clavirostris based on holotype BMNH 1822, a partial snout from the Hastings Beds of the Wealden Group of East Sussex, England. The genus name means "maimed beak", a reference to the damaged and eroded condition of the fossil; the specific name means "key snout", referring to its form in cross-section. Owen also reclassified Ornithocheirus cuvieri and O. sedgwickii as species within the genus Coloborhycnhus, though he did not designate any of these three as the type species. Owen considered the defining trait of the genus to be the location of the front tooth pairs high on the side of the upper jaws. However, in 1913 Reginald Walter Hooley concluded that this location was an artefact of the erosion and that the genus was indistinguishable from Criorhynchus simus, the second genus and species Owen erected in 1874. Hooley also ignored Owen's re-assignment of the two former Ornithocheirus species, leaving them in that genus. In 1967, Kuhn agreed with Hooley that Coloborhynchus clavirostris was a synonym of Criorhynchus simus. Furthermore, Kuhn was the first to formally designate C. clavirostris as the type species of the genus, rather than one of the Ornithocheirus species. Most later researchers followed these opinions, regarding Coloborhynchus as invalid relative to Criorhynchus. This changed in 1994 when Yuong-Nam Lee named Coloborhynchus wadleighi for a snout found in 1992 in the Albian age Paw Paw Formation Texas. The revival of the genus meant that of several related species, then assigned to other genera, had to be re-evaluated to determine whether or not they actually belonged to Coloborhynchus. In 2008, Taissa Rodrigues and Alexander Kellner re-formulated the key features of Coloborhynchus, again based mainly on the unique positions of the tooth sockets. Rodrigues and Kellner argued that Lee's C. wadleighi, which possessed some differences in the skull and teeth from C. clavirostris, and from an earlier time period, belonged in its own genus, which they named Uktenadactylus. A partial lower jaw originally named Tropeognathus robustus from the Romualdo Member of the Santana Formation in Brazil was assigned to Coloborhycnhus in 2001 by Fastnacht, as Coloborhynchus robustus. In 2002, David Unwin supported this position, and also synonymized the more well-known species Anhanguera piscator with C. robustus. Rodrigues and Kellner disagreed with this classification, however, noting that both did not possess the unique straightened crest beginning at the snout tip, or sideways pointed teeth, of C. clavirostris. Instead, Rodrigues and Kellner regarded both Anhanguera robustus and Anhanguera piscator as valid species of Anhanguera. Another Brazilian species from the Romualdo Member was named Coloborhynchus speilbergi by Veldmeijer in 2003. It shares one or two characters in common with C. clavirostris (such as a flattened upper surface of the snout), though Rodrigues and Kellner regarded them as dubious, and noted that they are also present in related species and so are not unique to Coloborhynchus. Rodrigues and Kellner also noted that C. speilbergi didn't have as high a tooth row (exposing the palate) as the type species. Its crest is also very thin, similar to Anhanguera, to which genus Kellner assigned it in 2006. Similarly, Kellner excluded C. araripensis (formerly assigned to the genus Santanadactylus) from the genus, based on lack of comparable diagnostic features. Unwin, in 2001, assigned the species Siroccopteryx moroccensis to Coloborhycnhus, based on its similarity to C. wadleighi (aka Uktenadactylus). Kellner, who regarded Uktenadactylus as a distinct genus in 2008, also regarded Siroccopteryx as distinct, and noted that like the other species assigned to Coloborhynchus, lacked its unique characteristics of the tooth row, a position also supported by Fastnacht in 2001. Finally, Unwin (in 2001) also re-assigned the two other species from the Cambridge Greensand to Coloborhycnhus: C. capito and C. sedgwickii, the second of which being one of the original members of the genus according to Richard Owen in 1874. According to Kellner, C. capito is too incomplete to fully compare to C. claviraostris, and its precise classification is open to debate. He noted that C. sedgwicki does not possess the unique features of C. clavirostris (in fact it lacks a crest altogether), and may instead belong to the same genus as "Ornithocheirus" compressirostris (=Lonchodectes). In 2013, Rodrigues and Kellner considered Coloborhynchus to be monotypic, containing only C. clavirostris, and placed most other species in other genera, or declared them nomina dubia. Палеонтологи определили птерозавра с самыми крупными зубами. К тому же Coloborhynchus capito назван крупнейшим из известных зубастых птерозавров: размах крыльев этого ящера достигал семи метров. «Два первых зуба каждой челюсти направлены вперёд и, возможно, были до 7 см длиной, а два зуба за ними — чуть больше 10 см, — рассказывает соавтор работы Дэвид Мартилл из Портсмутского университета (Великобритания). — Вместе они образовывали своего рода розочку, подходящую и для ловли рыбы, и для того, чтобы припугнуть конкурента». Дэвид Мартилл и Дэвид Анвин из Лестерского университета (Великобритания) проанализировали фрагментарное ископаемое из коллекции лондонского Музея естественной истории. Его нашли в альбском ярусе нижнемеловой эпохи (около 100 млн лет назад) геологической формации Кембридж-Гринсэнд на востоке Англии. В те времена окрестности Кембриджа находились под водой, но, возможно, на юге Лондона располагался небольшой остров. В этих широтах царил тропический климат. Судя по другим находкам, регион кишел рыбой, ихтиозаврами, плезиозаврами, крокодилами, черепахами, динозаврами (в том числе примитивными птицами). Новый птерозавр уступает крупнейшему беззубому собрату под названием Quetzalcoatlus — с его девятиметровым размахом крыльев. Результаты исследования будут опубликованы в журнале Cretaceous Research.
Ископаемые останки и реплики (1, 2, 3): Tags: Вымершие рептилии, Мел, авеметатарзалии, архозавроморфы, архозавры, диапсиды, монофенестраты, орнитохейриды, орнитохейройды, птеранодонтойды, птеродактили, птерозавры |
| May 7th, 2014 | |
| 08:41 pm [industrialterro] [Link] |
Cearadactylus Cearadactylus is a genus of large Early Cretaceous (Albian) pterosaurs from South America. The only known species is Cearadactylus atrox, described and named in 1985 by Giuseppe Leonardi and Guido Borgomanero. The name refers to the Brazilian state Ceará and combines this with Greek daktylos, "finger", a reference to the wing finger of pterosaurs. The Latin atrox means "frightful", a reference to the fearsome dentition of the species. The holotype is MN 7019-V (earlier CB-PV-F-O93), from the Romualdo Member of the Santana Formation. This fossil, a single skull with a length of 57 centimetres, was discovered on the Araripe plateau in northeastern Brazil. It was traded to Italy in 1983 and bought by Borgomanero for his collection. The skull is severely damaged, especially on the top, and was perhaps reconstructed by the fossil dealer. As shown by a later preparation by the Brazilian Museu Nacional, in the first preparation many serious mistakes were made. The fronts of the snout and of the lower jaws were confused leading to a reconstruction in which the anterior part of the head was upside down. The teeth were extensively restored and enlarged until the wider front of the jaws showed very large and robust teeth projecting outwards, forming a sort of "rosette". This kinked upper jaw and its interlocking teeth suggested a piscivourous diet, allowing the animal to keep hold of slippery fish. No crests seemed to be present. The new preparation made clear that a crest was present on the snout and that the rosette was a lot smaller. Many details were discovered that were useful in determining the phylogenetic position of Cearadactylus. The wingspan of Cearadactylus was by the describers estimated to have been around 4 metres (13 ft), with a weight of perhaps 15 kilograms (33 lb). Peter Wellnhofer in 1991 estimated a wingspan of 5.5 metres (18 ft). Leonardi did abstain from assigning the genus to a family. Wellnhofer created a special family Cearadactylidae, but this concept is no longer used. In 2000 Alexander Kellner concluded that is was related to, but lacking a crest not part of, the Anhangueridae within a larger Pteranodontoidea sensu Kellner. In 2002 David Unwin however stated it was a highly deviant member of Ctenochasmatidae. In 2010 Kellner entered the new information into three existing databases of pterosaur features, to calculate through cladistic analysis the position of Cearadactylus in the phylogenetic tree. Although the three resulting trees differed, all had in common that Cearadactylus was close to the Anhangueridae. In 1993 Fabio Marco Dalla Vecchia named a second species, Cearadactylus ligabuei. The specific name honours Giancarlo Ligabue, the director of the Centro Sudi Ricerche Ligabue in Venice. It is based on holotype CCSRL 12692/12713, again a heavily damaged crestless skull, 403 millimetres long. The skull consists of two pieces, the front and the back part, glued together by fossil traders; it is uncertain whether they belong to the same individual or indeed to the same species. Dalla Vecchia was himself not convinced the new species in fact belonged to Cearadactylus, but the skull was not sufficiently unique to base its own genus on yet still too different from known species to be assigned to them, so he created a new species for the genus the fossil most resembled. Later authors have consistently denied the identity referring to the taxon as "Cearadactylus" ligabuei. Dalla Vecchia estimated the wingspan at six metres; Kellner, pointing out that the skull is not larger than the C. atrox holotype, at five metres at the most. Dalla Vecchia assigned C. ligabuei to the Cearadactylidae. Kellner concluded it was probably a member of Anhangueridae; Unwin in 2002 even named it Anhanguera ligabuei. Steel e.a. (2005) suggested it was a Coloborhynchus ligabuei. Церадактиль (Ceradactylus) – летающий ящер с размахом крыльев 5,5 метров и в длину около 1,5 м. (из которых один череп составляет около 60 см.), обитал в середине мелового периода. Его окаменелости были обнаружены в 1983 г. на территории штата Сеара в Бразилии. Научное описание этого вида сделали Джузеппе Леонарди и Гвидо Боргоманеро в 1985 г. Специалисты полагают, что этот ящер, в отличие от других птерозавров, мог не только парить, но и активно взмахивать крыльями. Устройство челюстей и зубов говорит о преимущественно рыбном рационе, причем зубы этого ящера были достаточно большими, редкими, развернутыми наружу (для удержания скользкой добычи) и локализованными в передней части челюстей. На конце морды у церадактиля был небольшой гребень. Вероятно, этот птерозавр селился по берегам крупных рек, озер и морей. На суше эти ящеры были неуклюжими и, скорее всего, не могли взлетать с ровной поверхности. В качестве «взлетной площадки» они использовали выступы скал и утесы. Tags: Вымершие рептилии, Мел, авеметатарзалии, архозавроморфы, архозавры, диапсиды, монофенестраты, орнитохейройды, птеранодонтойды, птеродактили, птерозавры |
| 08:04 pm [industrialterro] [Link] |
Caulkicephalus Caulkicephalus is a genus of pterosaur, belonging to the Pterodactyloidea, from the Isle of Wight off the coast of England. Between 1995 and 2003 bone fragments of an unknown pterosaur were found at the Yaverland locality near Sandown. The discoveries were made in or from a brown clay layer from the Wessex Formation of the Wealden Group, stemming from the Early Cretaceous (Barremian age, about 130 million years ago). In 2005 a new genus was named and described by Lorna Steel, David Martill, David Unwin and John Winch. The type species is Caulkicephalus trimicrodon. The genus name is a translation of "Caulkhead", a traditional nickname for Isle of Wight residents, partially derived from Greek kephale, "head". The specific name, trimicrodon, means "three small teeth", in reference to the dentition. The holotype is IWCMS 2002.189.1, 2, 4: three pieces, more or less contiguous, of the front part of a snout. As paratypes have been referred: IWCMS 2002.189.3, a partial posterior skull roof; IWCMS 2003.2, a left quadrate; IWCMS 2003.4, a possible partial jugal; ICWMS 2002.237, a 44 millimetres long fragment of the first phalanx of the wing finger; IWCMS 2002.234.1-4, four, together 245 millimetres long, contiguous fragments of a first phalanx; IWCMS 2002.233, a possible distal end, 64 millimetres long, of a second phalanx; IWCMS 2002.236, a fragment of the shaft of possibly the fourth phalanx; and IWCMS 2003.3, a probable fragment of a hindlimb bone. The fossils have only been slightly compressed. The snout fragments have a combined length of 290 millimetres. On the snout top the base of a crest is visible, not quite reaching its rounded tip. The teeth have, apart from some replacement teeth present deep in the jaw, been lost but their number, orientation and size can be inferred from the tooth sockets, which however are partly missing at the right side. These are oval and slightly elevated above the jaw bone. The first two tooth pairs were pointed somewhat to the front; the teeth more to the back pointed more sideways; the most posterior preserved stood perpendicular to the jaw. The teeth increased in size until the third pair which was the largest. The fourth pair was equal to the first but the fifth, sixth and seventh pairs were markedly smaller, less than half in size; it is this feature which is recalled by the specific name. Pairs eight, nine and ten again equalled the first. After a narrow hiatus between the second and third snout fragment four tooth sockets are present at each side of the latter, but these are not placed in opposite pairs. The number of teeth in the upper jaw thus seems to have been at least fourteen. The smaller sized teeth were placed in a constriction of the snout, which thus had a broader end with larger teeth, a so-called "prey grab", usually interpreted as an adaptation to catch slippery prey such as fish. The posterior skull fragment, a braincase which is rather damaged, shows on its top the base of a parietal crest, probably pointing towards the back. It seems to have been separate from the snout crest. Caulkicephalus was by the describers assigned to the Ornithocheiridae in view of the narrowing in the middle of the snout. The snout crest was seen as an indication it belonged to the more general Ornithocheiroidea sensu Unwin, whereas the parietal crest was suggested to have been a synapomorphy, a shared new feature, of the more narrow group of the Euornithocheira. Unique characters of the species itself, its autapomorphies, are the details of its dentition, the downwards and backwards running suture between the praemaxilla and maxilla, and the fact the median ridge of the palate begins (or ends) at the ninth tooth pair. The layer the fossils were found in, does not consist of marine sediments, but contains land plant debris; this is seen as an indication of a more terrestrial habitat. David Martill estimated Caulkicephalus had a wingspan of around 5 metres (16.5 ft). Tags: Вымершие рептилии, Мел, авеметатарзалии, архозавроморфы, архозавры, диапсиды, монофенестраты, орнитохейриды, орнитохейройды, птеранодонтойды, птеродактили, птерозавры |
| April 30th, 2014 | |
| 03:05 pm [industrialterro] [Link] |
Boreopterus Boreopterus is a genus of pterodactyloid pterosaur from the Barremian-Aptian-age Lower Cretaceous Yixian Formation of Dalian, Liaoning, China. The genus was in 2005 named by Lü Jinchang and Ji Qiang. The type species is Boreopterus cuiae. The genus name is derived from Greek boreios, "northern" and pteron, "wing". The specific epithet was chosen to dedicate Cui Xu. The genus is based on holotype JZMP-04-07-3, a nearly complete but crushed skeleton and skull. The skull is 235 millimeters long (9.25 inches), low and elongated with a rounded tip. Its wingspan is estimated to have been around 1.45 meters (4.76 feet). Its teeth, especially the anterior nine pairs, are quite large, forming a mesh of sharp teeth at the front of the mouth; the third and fourth teeth from the front are the largest. There are at least 27 teeth in each side of both the upper and lower jaws, which is a large amount. Lü and Ji initially placed Boreopterus in the Ornithocheiridae when they described it in 2006, a classification which was supported later that year by David Unwin. However, Lü in 2006 published a cladistic analysis showing Boreopterus to be the sister taxon of Feilongus (together forming the new family, Boreopteridae) in a position more basal than Haopterus. In 2013, a more comprehensive study of pterosaur relationships supported the close relationship of Boreopterus and Feilongus, as well as their relatively basal status among pterodactyloids. Andres & Myers (2013) found the "boreopterids" as the sister group of Cycnorhamphus within the archaeopterodactyloid group Gallodactylidae. Pterosaurs like Boreopterus are interpreted by Unwin as soaring animals, like today's albatrosses and frigatebirds. However, it has also been suggested that boreopterids foraged while swimming, trapping small prey with their needle-like teeth, a method similar to that of modern Platanista dolphins. It has been suggested that the closely related Zhenyuanopterus was merely the adult form of this animal. Boreopteridae (meaning "northern wings") is a group of ornithocheiroid pterosaurs from the Aptian-age Lower Cretaceous Yixian Formation of Liaoning, China. In 2006, Lu and colleagues named the clade Boreopteridae for the clade containing the common ancestor of Boreopterus and Feilongus and all its descendants, which the authors reclassified as close relatives of the ornithocherids. (Feilongus had originally been considered a gallodactylid). Many possible boreopterids were subsequently described, one possible example being Aetodactylus, which has been claimed to be similar to Boreopterus. Originally considered close relatives of the ornithocheirids, many of these supposed boreopterids have been found to belong to other groups of the pterodactyloid lineage. Boreopterus and Feilongus were found by Andres and colleagues in 2013 to be closely related to Cycnorhamphus, making them members of the Gallodactylidae as had been originally thought when Feilongus was discovered. A subsequent analysis including the other supposed boreopterids found that Boreopterus itself, and therefore the name Boreopteridae, was indeed a member of the ornithocheiroid clade, but that Feilongus was in fact a ctenochasmatoid closely related to Gnathosaurus. According to Andres and colleagues (2014), the true boreopterid clade is limited to Boreopterus, Guidraco, and Zhenyuanopterus. The known taxa come from the Yixian Formation of Liaoning, which represented a lake system, suggesting that these animals occurred in freshwater habitats. They are thought to have foraged while swimming, trapping prey with their needle-like teeth; this method of fishing was probably analogous to that of Platanista dolphins, which share a similar dentition. Many possible ornithocheirid remains might actually belong to boreopterids, a possible example being Aetodactylus, which has been claimed to be similar to Boreopterus Размеры тела в сравнении с человеком: Tags: Вымершие рептилии, Мел, авеметатарзалии, архозавроморфы, архозавры, бореоптериды, диапсиды, монофенестраты, орнитохейройды, птеранодонтойды, птеродактили, птерозавры |
| 02:34 pm [industrialterro] [Link] |
Bakonydraco Bakonydraco is a genus of azhdarchoid pterosaur of the Santonian-age Upper Cretaceous Csehbánya Formation of the Bakony Mountains, Iharkút, Veszprém, western Hungary. The genus was named in 2005 by David Weishampel, Atilla Ősi and Jianu Coralia. The type species is Bakonydraco galaczi. The genus name refers to the Bakony Mountains and to Latin draco, "dragon". The specific epithet galaczi honors Professor András Galácz, who helped the authors in the Iharkút Research Program, where fossils are since 2000 found in open-pit mining of bauxite, among them the remains of pterosaurs, the first ever discovered in Hungary. Bakonydraco is based on holotype MTM Gyn/3, a nearly complete mandibula, a fusion of the lower jaws. Also assigned to it, as paratype, is MTM Gyn/4, 21: parts from another jaw's symphysis (the front parts, having fused into a single blade-like structure, of the two lower jaws); azhdarchid wing bones and neck vertebrae from the same area may also belong to it. The lower jaws are toothless and the two halves of the mandibula are frontally fused for about half of its overall length, forming a long, pointed section that is compressed side-to-side and also expanded vertically, giving it a somewhat spearhead- or arrowhead-like shape from the side. This expansion occurs both on the lower edge and on the top surface, where the most extreme point corresponds with a transverse ridge which separates the straight back half of the symphysis from the pointed end in the front. The jaws of MTM Gyn/3 are 29 centimeters long (11.4 inches), and the wingspan of the genus is estimated to be 3.5 to 4 meters (11.5 to 13.1 feet), which is medium-sized for a pterosaur. Because the jaws are relatively taller than other azhdarchids, and reminiscent of Tapejara, Bakonydraco may have fed differently from other azdarchids. It could have been a piscivore (feeding on small fish), or a frugivore. The discovery of this genus establishes the presence of azhdarchids in the Late Cretaceous of Hungary, suggesting that there as elsewhere they had become the dominant pterosaurs. Andres & Myers (2013) have proposed that Bakonydraco is actually a tapejarid, a sister taxon to Tapejara and Tupandactylus. Indeed, the original paper describing this species compared the holotype jaw to Tapejara and Sinopterus, implicating its affinities to this clade (or at least a large amount of convergence). If Bakonydraco is a tapejarid, it represents the only Late Cretaceous record of Tapejaridae known to date. Tags: Вымершие рептилии, Мел, авеметатарзалии, аждархойды, архозавроморфы, архозавры, диапсиды, монофенестраты, орнитохейройды, птеродактили, птерозавры |
| 12:54 pm [industrialterro] [Link] |
Azhdarcho Azhdarcho /ɑːʒˈdɑrxoʊ/ is a genus of pterodactyloid pterosaur from the late Cretaceous Period of the Bissekty Formation (middle Turonian stage, about 92 million years ago) of Uzbekistan. It is known from fragmentary remains including the distinctive, elongated neck vertebrae that characterizes members of the family Azhdarchidae, which also includes such giant pterosaurs as Quetzalcoatlus. The name Azhdarcho comes from the Uzbek word azhdarkho [adʒˈdarχɒ], the name of a dragon in Uzbek mythology. The type species is Azhdarcho lancicollis. The specific epithet lancicollis is derived from the Latin words lancea (meaning "lance" or "spear") and collum ("neck"). The fossil remains of Azhdarcho were recovered in the Kyzyl Kum desert (from the Taykarshinskaya unit of the Bissekty Formation) by Lev A. Nesov during expeditions to Central Asia in 1974-1981. The type specimen, given the catalog number TsNIGRmuzey 1/11915, consists of an anterior neck vertebra. Twelve paratypes were referred, including several other neck vertebrae, elements from the wing and leg, and pieces of the jaw. These specimens, along with other vertebrate fossils collected during the expeditions, were deposited at the F.N. Chernyshev Central Geologic Exploration Museum in St. Petersberg. In his description of the type specimen of Azhdarcho lancicollis, Nesov noted its distinctive neck vertebrae, which are extremely elongated and round in cross section at mid-length. He pointed out similar characteristics in several other pterosaurs, and used them to erect the new subfamily Azhdarchinae, within the Pteranodontidae. Nesov also referred Quetzalcoatlus and Arambourgiania (then known as Titanopteryx) to this subfamily, which was subsequently re-classified as the family Azhdarchidae. He also suggested that similar, thin-walled pterosaur bones from the Lance Formation of Wyoming could be assigned to a species of Azhdarcho, using this as evidence of commonalities between the fauna of Late Cretaceous central Asia and western North America. However, subsequent research has not followed this suggestion, and A. lancicollis is the only currently recognized species of Azhdarcho. In the original description of Azhdarcho, Nesov noted that because of the way the vertebrae articulated, the pterosaur would have had very limited flexibility in the neck. Azhdarcho could not rotate its neck at all, though it could flex the neck vertically to a certain degree. Nesov suggested that pterosaurs like Azhdarcho may have fed in a manner similar to the modern Skimmer, with their long necks allowing them to scoop prey from the water's surface and small depths without needing to dive. However, recent research has shown that skimming requires more energy and anatomical specializations than previously thought, and that large pterosaurs like Azhdarcho probably were not capable of skimming. The long neck would also have allowed azhdarchids to hunt for food in the water or on the bottom while swimming, or to hunt poorly-flying vertebrates in the air, though Nesov also suggested that the animal would have needed stable weather conditions to fly well, and suggested azhdarchid habitats needed to be dominated by even, mild winds. ( Read More )</span>
Ископаемые останки (1, 2, 3, 4): Tags: Вымершие рептилии, Мел, авеметатарзалии, аждархиды, аждархойды, архозавроморфы, архозавры, диапсиды, монофенестраты, орнитохейройды, птеродактили, птерозавры |
| April 23rd, 2014 | |
| 01:42 pm [industrialterro] [Link] |
Anhanguera Anhanguera (meaning "old devil") is a genus of pterodactyloid pterosaur known from the Lower-Cretaceous (Aptian age, 112Ma) Santana Formation of Brazil, with referred specimens found in the Upper Chalk Formation and Cambridge Greensand of the UK (up to the late Cenomanian age, 94Ma). This pterosaur is closely related to Ornithocheirus, and belongs in the family Ornithocheiridae within its own subfamily, Anhanguerinae. Anhanguera was a fish-eating animal with a wingspan of about 4.5 m (15 ft). Like many other ornithocheirids, Anhanguera had a rounded crests at front of its upper and lower jaws, which were filled with angled, conical but curved teeth of various sizes and orientations. Like many of its relatives, the jaws were tapered in width, but expanded into a broad, spoon-shaped rosette at the tip. It is distinguished from its relatives by subtle differences in the crest and teeth: unlike its close relatives Coloborhynchus and Ornithocheirus, the crest on the upper jaw of Anhanguera did not begin at the tip of the snout, but was set farther back on the skull. Like many ornithocheiroids, (most notably the pteranodonts but also in ornithocheirids such as Ludodactylus) Anhanguera had an additional crest protruding from the back of the skull. However, it was reduced to a small, blunt projection in these animals. A study in 2003 showed that Anhanguera held its head at an angle to the ground due to its inner ear structure, which helped the animal detect its balance. There are several recognized species of Anhanguera. A. santanae and A. blittersdorfi are known from several fragmentary remains including skulls from the Santana Formation of Brazil. A. cuvieri and A. fittoni, initially described as belonging to the genus Pterodactylus and then Ornithocheirus, are from a slightly later period (Albian) from England, while fragments of pterosaurs that may have affinities with Anhanguera have also been found in Queensland, Australia. The well-known species A. piscator has been redescribed as belonging to the genus Coloborhynchus (Veldmeijer, 2003). Anhangueridae is a group of pterosaurs within the suborder Pterodactyloidea. They were among the last pterosaurs to possess teeth. A recent study discussing the group considered the Anhangueridae to be typified by a premaxillary crest and a lateral expansion in the distal rostrum. The same study presented a cladistic analysis, for which an "Agreement subtree" was calculated. The Anhangueridae was found to be sister taxon to the large crested "Tropeognathus". ( Read More ) Репродукции (1, 2, 3, 4, 5, 6, 7, 8): ( Read More ) Ископаемые останки (1, 2, 3, 4, 5): Tags: Вымершие рептилии, Мел, авеметатарзалии, аньянгуэриды, архозавроморфы, архозавры, диапсиды, монофенестраты, орнитохейройды, птеранодонтойды, птеродактили, птерозавры |
| 12:56 pm [industrialterro] [Link] |
Arambourgiania Arambourgiania is a pterosaur from the Late Cretaceous (Maastrichtian) of Jordan. It was one of the largest members of this group. In the early forties, a railway worker during repairs on the Amman-Damascus railroad near Russeifa found a two feet long fossil bone. In 1943 this was acquired by the director of a nearby phosphate mine, Amin Kawar, who brought it to the attention of a British archeologist, Fielding, after the war. This generated some publicity — the bone was even shown to Abdullah I of Jordan — but more importantly, it made the scientific community aware of the find. In 1953 the fossil was sent to Paris, where it was examined by Camille Arambourg of the Muséum national d'histoire naturelle. In 1954, he concluded the bone was the wing metacarpal of a giant pterosaur. In 1959, he named a new genus and species: Titanopteryx philadelphiae. The genus name meant "titan wing" in Greek; the specific name refers to the name of Amman in Antiquity: Philadelphia. Arambourg let a plaster cast be made and then sent the fossil back to the phosphate mine; this last aspect was later forgotten and the bone was assumed lost. In 1975 Douglas A. Lawson, studying the related Quetzalcoatlus, concluded the bone was not a metacarpal but a cervical vertebra. In the eighties, Russian paleontologist Lev Nesov was informed by an entomologist that the name Titanopteryx had already been given by Günther Enderlein to a fly from the Simulidae family in 1934. Therefore, in 1987 he renamed the genus into Arambourgiania, honouring Arambourg. However, the name "Titanopteryx" was informally kept in use in the West, partially because the new name was assumed by many to be a nomen dubium. Early 1995, paleontologists David Martill and Eberhard Frey traveled to Jordan in an attempt to clarify matters. In a cupboard of the office of the Jordan Phosphate Mines Company they discovered some other pterosaur bones: a smaller vertebra and the proximal and distal extremities of a wing phalanx — but not the original find. However, after their departure to Europe engineer Rashdie Sadaqah of the mine investigated further and in 1996 established it had been bought from the company in 1969 by geologist Hani N. Khoury who had donated it in 1973 to the University of Jordan; it was still present in the collection of this institute and now could be restudied by Martill and Frey. The holotype, VF 1, consists of a very elongated cervical vertebra, probably the fifth. Today the middle section is missing; the original find was about 62 centimetres long, but had been sawed into three parts. Most of the fossil consists of an internal infilling or mould; the thin bone walls are missing on most of the surface. The find had not presented the whole vertebra; a piece was absent from its posterior end as well. Frey and Martill estimated the total length to have been 78 centimetres, using for comparison the relative position of the smallest shaft diameter of the fifth cervical vertebra of Quetzalcoatlus. From this again the total neck length was extrapolated at about three metres. From the relatively slender vertebra the length dimension was then selected to be compared to that of Quetzalcoatlus, estimated at 66 centimeters long, resulting in a ratio of 1.18. Applying that ratio to the overall size, Frey and Martill in 1998 concluded that the wingspan of Arambourgiania had been twelve to thirteen metres, compared with the ten to eleven metres of Quetzalcoatlus, and that Arambourgiania was thus the largest pterosaur then known. Later estimates have been more moderate, sometimes as low as seven metres. Frey and Martill rejected the suggestion that Arambourgiania was a nomen dubium or identical to Quetzalcoatlus and affirmed its validity in relation to "Titanopteryx". Nesov in 1984 had placed the species within Azhdarchinae, part of the Pteranodontidae; the same year Kevin Padian placed it within Titanopterygidae. Both concepts have fallen into disuse now that such forms are commonly assigned to the Azhdarchidae.
Tags: Вымершие рептилии, Мел, авеметатарзалии, аждархиды, аждархойды, архозавроморфы, архозавры, диапсиды, монофенестраты, орнитохейройды, птеродактили, птерозавры |
| 10:48 am [industrialterro] [Link] |
Alanqa Alanqa (от араб. «Al Anqa» — феникс) — вымерший род птеродактелей, обитавший в меловом периоде примерно 95 млн лет назад. Ископаемые останки были найдены в отложениях сеноманского яруса в Марокко и описаны в 2010 году. Единственный известный вид — Alanqa saharica Ibrahim et a., 2010. Название птеродактиля Alanqa saharica происходит от арабского слова «Al Anqa», которое означает «Феникс», а видовое название saharica указывает на то, что данный вид был обнаружен в пустыне Сахара. Описание A. saharica основано на исследовании челюстной кости длиной 344 мм, составленной из трёх отдельных фрагментов. Также были найдены фрагменты шейных позвонков, принадлежавших, вероятно, A. saharica. Длина птеродактеля составляла примерно шесть метров. Отличительной особенностью A. saharica является отсутствие зубов. Является одним из древнейших известных представителей семейства аждархид. Окаменелости птерозавра находились на территории древней Гондваны (на территории современного Марокко), однако подавляющее большинство сравнимых по возрасту экземпляров аждархид было обнаружено на землях бывшей Лавразии. Так же рядом с останками Alanqa были обнаружены 2 других вида птерозавров, что свидетельствует о тесном соседстве разных видов птерозавров на одной территории и на одном промежутке времени. Aided by local villagers, a team of paleontologists had been excavating at several locations in the Kem Kem Beds during April, and November to December 2008, uncovering remains of several different pterosaurs. The material was fragmentary, and the type locality for Alanqa is Aferdou N'Chaft, near the village of Begaa and 10 km to the north-east of Taouz. Alanqa is known only from five fragments of the front upper and lower jaws, and possibly a neck vertebra, representing the single type species Alanqa saharica. Two of these fragments were first described, but not named, by Wellnhofer and Buffetaut in 1999. Three additional jaw specimens, including a better preserved upper jaw, were described and named by Ibrahim and colleagues in 2010. The jaws were straight and pointed, like those of Quetzalcoatlus and Zhejiangopterus, so while it was originally proposed as a pteranodontid, it is more likely Alanqa was an azhdarchid. Based on comparison to related species, the Alanqa saharica the individuals known from jaw specimens probably had wingspans of about 4 meters (about 13 ft). However, according to Ibrahim and colleagues, the vertebra (which probably belonged to the same species) appeared to come from a larger individual, measuring about 6 meters (about 20 ft) in wingspan. ( Read More ) Tags: Вымершие рептилии, Мел, авеметатарзалии, аждархиды, аждархойды, архозавроморфы, архозавры, диапсиды, монофенестраты, орнитохейройды, птеродактили, птерозавры |
| April 20th, 2014 | |
| 07:04 pm [industrialterro] [Link] |
Aetodactylus Aetodactylus (meaning "eagle finger") is a genus of ornithocheirid pterodactyloid pterosaur. It is known from a lower jaw discovered in Upper Cretaceous rocks of northeastern Texas, United States. Aetodactylus is only the second ornithocheirid genus to be discovered in North America. Aetodactylus is based on SMU 76383 (Shuler Museum of Paleontology, Southern Methodist University), a nearly complete lower jaw lacking the right retroarticular process (the bony prong posterior to the jaw joint), part of the posterior end of the mandibular symphysis (where the two halves of the lower jaw meet), and all but two teeth. This specimen was found in 2006 by Lance Hall near a construction site in Mansfield, near Joe Pool Lake (recorded as SMU Loc. 424). The rock it was found in is a calcareous marine sandstone rich in mud–sized particles, from the middle Cenomanian-age (approximately 97 million years old) Tarrant Formation. Also found were fish teeth and vertebrae, and indeterminate bones. The Tarrant Formation is the lowest rock unit of the Cenomanian–Turonian–age Eagle Ford Group. Aetodactylus was named by Timothy S. Myers of SMU in 2010. The type species is A. halli, named in honor of the discoverer. Aetodactylus is differentiated from other ornithocheirids by several anatomical details of the lower jaw, including the slight expansion of the anterior end of the lower jaw, the strong vertical compression of the symphysis, the relatively constant spacing of the teeth, and the slight upward curve of the lower jaw. Myers found that Aetodactylus compared best with the Chinese genus Boreopterus. Aetodactylus represents one of the youngest definitive records of ornithocheirids. The jaw SMU 76383 is 38.4 centimetres (15.1 in) long, 15.8 centimetres (6.2 in) (~41%) of which is joined left and right jaws. 27 pairs of teeth were present; the two remaining teeth are pointed, curved slightly backward, flattened from side to side, and slender. The tip of the jaw is slightly expanded (to 1.6 centimetres (0.63 in) from a minimum of 1.3 centimetres (0.51 in) just posterior) and contains the first four pairs of teeth, with the first pair projecting forward. Based on the size of the tooth sockets, the teeth of the second and third pairs were largest, with tooth size decreasing posteriorly. There are small pits between the posterior teeth, interpreted as points where the teeth of the upper jaw rested against the lower jaw. These pits disappear partway along the tooth row, suggesting that the anterior teeth of the upper jaws were longer and projected outwards to a degree. Unlike some other ornithocheirids, such as Anhanguera, Coloborhynchus, and Ornithocheirus, there is no bony crest on the lower jaw. It is possible that Aetodactylus might be a boreopterid, as Myers identifies it as being closely related to Boreopterus, and many ornithocheirid remains might belong to boreopterids instead. ( Read More )
Tags: Вымершие рептилии, Мел, авеметатарзалии, архозавроморфы, архозавры, диапсиды, монофенестраты, орнитохейриды, орнитохейройды, птеранодонтойды, птеродактили, птерозавры |
| May 23rd, 2012 | |
| 08:22 pm [industrialterro] [Link] |
Puntanipterus Puntanipterus was a genus of dsungaripterid pterodactyloid pterosaur from the Upper Jurassic-Lower Cretaceous La Cruz Formation of San Luis, Argentina. The genus was in 1975 named by José Bonaparte and Teresa Sánchez. The type species is Puntanipterus globosus. The genus name refers to the Puntanos, the colloquial name for the inhabitants of the province of San Luis after the old name of their capital "San Luis de la Punta de los Venados", and combines this with a Latinized Greek pteron, "wing". The specific name means "spherical" in Latin, a reference to the form of the lower tibia. It is based on holotype PVL 3869 (earlier FML 3869) found in 1972, a 105 millimetres long tibiotarsus and seven centimetres long fibula; referred to it were a back vertebra and a wing and foot phalanx. The leg bones were described as similar to those of Pterodaustro (from slightly younger rocks), except for having an expanded spherical joint at the ankle and spiny processes on the side faces of the tibia at that end. Bonaparte in 1978 classified Puntanipterus as a member of the Pterodaustridae. The same year Peter Wellnhofer was more careful and limited his assessment to a Pterodactyloidea incertae sedis. In 1980 Peter Galton concluded it belonged to the Dsungaripteridae. It was still by many considered to be a dsungaripterid by the time Peter Wellnhofer published The Illustrated Encyclopedia of Pterosaurs (several editions in the 1990s). However, in the nineties several tibiae conforming to that of Puntanipterus were found in the same strata as Pterodaustro; a direct comparison is only impossible because more complete specimens of the latter are always very compressed, deforming the ankle morphology; but smaller fragments containing not-compressed ankles all have the build of a Puntanipterus tibiotarsus. This is by South American workers seen as a strong indication that both forms are identical. Glut reports a personal communication from Laura Codorniú and Luis Chiappe (2004) that Puntanipterus should be regarded as a junior synonym of Pterodaustro, but it remains to be seen if this will be supported in the future; it was not done in David Unwin's The Pterosaurs: From Deep Time, published in 2006 (he recognized it as a possibly valid species of uncertain relationships).
Tags: Вымершие рептилии, Юра, авеметатарзалии, аждархойды, архозавроморфы, архозавры, джунгариптероиды, диапсиды, монофенестраты, орнитохейройды, птеродактили, птерозавры |
| 07:59 pm [industrialterro] [Link] |
Pterodactylus Pterodactylus ( The name derives from the Greek words pteron (πτερόν, meaning 'wing') and daktylos (δάκτυλος, meaning 'finger') and refers to the way in which the wing is supported by one large finger. Pterodactylus is known from over 27 fossil specimens, and though most of those are juveniles, many preserve complete skeletons. The discovery of several specimens with well-preserved soft tissue traces has allowed scientists to faithfully reconstruct the life appearance of Pterodactylus. Pterodactylus was a relatively small pterosaur, with an estimated adult wingspan of about 1.5 meters (5 ft) in P. antiquus. Other "species" were once thought to be smaller. However, these smaller specimens have been shown to represent juveniles of Pterodactylus, as well as its contemporary relatives Ctenochasma, Germanodactylus and Gnathosaurus. The skulls of adult Pterodactylus were long and narrow with about 90 large, conical teeth. The teeth extended back from the tips of both jaws, and became smaller farther away from the jaw tips (unlike some relatives, where teeth were absent in the upper jaw tip and were relatively uniform in size). The teeth extended farther back into the jaw than in close relatives, as some were present below the front of the nasoantorbital fenestra, the largest opening in the skull. Unlike related species, the skull and jaws were straight, not curved upwards. A small, hooked beak was present in the very tips of the jaws, with both upper and lower hook no larger than the teeth that surrounded them. The neck was long, and covered in long, bristle-like pycnofibres. A throat pouch extended from about the middle of the lower jaw to the upper part of the neck.ъ Pterodactylus, like related pterosaurs, had a crest on its skull composed mainly of soft tissues. In adult Pterodactylus, this crest extended between the back edge of the antorbital fenestra (the largest opening in the skull) and the back of the skull. The back of the crest extended upward into a backward-curving cone-shaped structure. The crest was composed mainly of long, hardened fibres (twisted together in a spiral pattern inside the conical part of the crest), and covered in scales. In at least one specimen of P. longicollum, the crest had a short bony base, also seen in related pterosaurs like Germanodactylus. Crests have only been found on large, fully adult specimens of Pterodactylus, indicating that this was a display structure and only developed when individuals reached maturity. The wings were long, and the wing membranes appear to have lacked the furry covering of pycnofibres present in some other pterosaurs (such as Pterorhynchus and Jeholopterus). The wing membrane extended between the fingers and toes as webbing, and a uropatagium (secondary membrane between the feet and tail) was present, as well as a propatagium (membrane between the wrist and shoulder). Both the finger and toe claws were covered in keratin sheaths that extended and curved into sharp hooks well beyond their bony cores. Like other pterosaurs (notably Rhamphorhynchus), Pterodactylus specimens can vary considerably based on age or level of maturity. Both the proportions of the limb bones, size and shape of the skull, and size and number of teeth changed as the animals grew. Historically, this has led to various growth stages (including growth stages of related pterosaurs) being mistaken for new species of Pterodactylus. Several detailed studies using various methods to measure growth curves among known specimens have demonstrated that there is actually only one valid Pterodactylus species, P. antiquus. The youngest immature Pterodactylus specimens have a small number of teeth (as few as 15), and the teeth have a relatively broad base. The teeth of older specimens are both narrower and more numerous (up to 90 teeth are present in some specimens). Pterodactylus specimens can be divided into two distinct year classes. In the first year class, the skulls are only 15-45mm in length. The second year class is characterized by skulls 55-95mm long, but still immature. These first two size groups were once classified as juveniles and adults of the species P. kochi, until further study showed that even the supposed "adults" were immature. A third year class is represented by specimens of the "traditional" P. antiquus, as well as a few isolated, large specimens once assigned to P. kochi that overlap P. antiquus in size. However, all specimens in this third year class also show sign of immaturity. Fully mature Pterodactylus specimens remain unknown, or may have been mistakenly classified as a different genus. The distinct year classes of Pterodactylus antiquus specimens show that this species, like the contemporary Rhamphorhynchus muensteri, likely bred seasonally and grew consistently during its lifetime. A new generation of 1st year class P. antiquus would have been produced seasonally, and reached 2nd-year size by the time the next generation hatched, creating distinct 'clumps' of similarly-sized and aged individuals in the fossil record. The smallest size class probably consisted of individuals that had just begun to fly and were less than one year old. The second year class represents individuals one to two years old, and the rare third year class is composed of specimens over two years old. This growth pattern is similar to modern crocodilians, rather than the rapid growth of modern birds. Comparisons between the scleral rings of Pterodactylus antiquus and modern birds and reptiles suggest that it may have been diurnal. This may also indicate niche partitioning with contemporary pterosaurs inferred to be nocturnal, such as Ctenochasma and Rhamphorhynchus. Numerous species have been assigned to Pterodactylus in the years since its discovery. In the first half of the nineteenth century any new pterosaur species would be named Pterodactylus, which thus became a typical "waste-basket taxon". Even after clearly different forms had later been given their own generic name, new species would be created from the very productive late Jurassic German sites, often based on only slightly different material. Around 1980, subsequent revisions by Peter Wellnhofer had reduced the number of recognized species to about half a dozen. Many species assigned to Pterodactylus had been based on juvenile specimens, and subsequently been recognized as immature individuals of other species or genera. By the 1990s it was understood that this was even true for part of the remaining species. P. elegans, for example, was found by numerous studies to be an immature Ctenochasma. Another species of Pterodactylus based on small, immature specimens is P. micronyx. However, it has been difficult to determine exactly of what genus and species P. micronyx might be the juvenile form. Stéphane Jouve, Christopher Bennett and others suggested that it probably belongs either to Gnathosaurus subulatus or one of the Ctenochasma species, but more data and study would be required to determine which one. The only well-known and well-supported species left were P. antiquus and P. kochi. However, most studies since the 1990s have found little reason to separate even these two, and have treated them as synonymous. In 1996, Bennett suggested that the differences between specimens of P. kochi and P. antiquus could be explained by differences in age. In a 2004 paper, Jouve used a different method of analysis and recovered the same result, showing that the "distinctive" features of P. kochi were age-related, and using mathematical comparison to show that the two forms are different growth stages of the same species. A special case is P. longicollum, named by von Meyer in 1854, based on a large specimen with a long neck and fewer teeth. Many researchers, including David Unwin, have found P. longicollum to be distinct from P. kochi and P. antiquus. Unwin found P. longicollum to be closer to Germanodactylus and therefore requiring a new genus name. It has sometimes been placed in the genus Diopecephalus because Harry Govier Seeley based this genus partly on the P. longicollum material. However, it was shown by Bennett that the type specimen later designated for Diopecephalus was a fossil belonging to P. kochi, and no longer thought to be separate from Pterodactylus. Diopecephalus is therefore a synonym of Pterodactylus, and as such is unavailable for use as a new genus for "P." longicollum.
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Tags: Вымершие рептилии, Юра, авеметатарзалии, архозавроморфы, архозавры, диапсиды, ктенохазматоидеи, монофенестраты, птеродактили, птерозавры |
| May 22nd, 2012 | |
| 07:26 pm [industrialterro] [Link] |
Gnathosaurus Gnathosaurus (meaning 'jaw lizard') is a genus of ctenochasmatid pterosaur known from a single species, G. subulatus, described in 1833. This pterosaur had an estimated wingspan of about 1.7 meters. The slender, 28-cm-long skull had up to 130 needle-like teeth arranged laterally around the spoon-shaped tip. Fragments of Gnathosaurus jaw were first discovered in 1832 in the Solnhofen limestones of Southern Germany but were mistaken for a piece of teleosaurid crocodile jaw, hence the synonym Crocodylus multidens. Only when a complete skull was found in 1951 this animal was found to have been a pterosaur. The teeth arranged in a spoon shape may have been used to strain water for small animals, although this is conjectural. Several paleontologists, such as Christopher Bennett, have suggested that a purported tiny Pterodactylus species, P. micronyx, is likely a juvenile of Gnathosaurus subulatus. Ctenochasmatoidea is a group of pterosaurs within the suborder Pterodactyloidea. The earliest known ctenochasmatoid remains have been found in the Stonesfield Slate formation (UK), which dates to the Bathonian stage of the Middle Jurassic, dated to about 166 million years ago.
Tags: Вымершие рептилии, Юра, авеметатарзалии, архозавроморфы, архозавры, диапсиды, ктенохазматоидеи, монофенестраты, птеродактили, птерозавры |
| 07:02 pm [industrialterro] [Link] |
Germanodactylus Germanodactylus ("German finger") is a genus of dsungaripteroid pterodactyloid pterosaur from Late Jurassic-age rocks of Germany, including the Solnhofen limestone. Its specimens were long thought to pertain to Pterodactylus. Its head crest is a distinctive feature. Germanodactylus is described as being "raven-sized" in weight. G. cristatus had a 0.98 wingspan (3.2 ft) and a 13 centimeter long (5.1 in) skull, while G. rhamphastinus was somewhat larger, with a 1.08 meter wingspan (3.5 ft) and a skull 21 centimeters long (8.3 in). Germanodactylus is known for its head crest, which had a bony portion (a low ridge running up the midline of the skull) and a soft-tissue portion that more than doubled its height. The bony part does not go as far up the head in G. cristatus as in G. rhamphastinus. The soft-tissue portion was not known early on, being first described in 2002 by S. Christopher Bennett. It was probably composed of cornified epidermis. Germanodactylus is the first genus for which a soft-tissue component of the crest is known, but similar structures were probably widespread among pterosaurs. This genus is unspecialized compared to the pterosaurs of the Cretaceous, and has had varying placements in Pterosauria. Yang Zhongjian, who named the genus, gave it its own family Germanodactylidae. Bennett included the genus in the family Pterodactylidae, and Alexander W.A. Kellner found it to be related to Pterodactylus in his 2003 phylogenetic analysis. David M. Unwin, on the other hand, preferred to consider it a basal dsungaripteroid, a group that evolved into dedicated shellfish-eaters. G. cristatus is based on specimen BSP 1892.IV.1, from the Solnhofen limestone of Eichstätt, Germany. It was originally described by Plieninger in 1901 as a specimen of Pterodactylus kochi, and was given its current specific name by Carl Wiman in 1925, meaning "crested" in Latin. Yang Zhongjian determined that it deserved its own genus in 1964. Second species G. ramphastinus (in 1858 accidentally revised to rhamphastinus by Christian Erich Hermann von Meyer) was named as a distinct species long before G. cristatus, described by Johann Andreas Wagner in 1851 as a species of the now deprecated genus Ornithocephalus. The specific name refers to the toucan, ramphastinos in Greek. It is based on specimen BSP AS.I.745, a skeleton from the slightly younger Mörnsheimer Limestone of Daiting, Germany. Peter Wellnhofer added it to Germanodactylus in 1970, although Maisch and his coauthors have suggested that it deserves its own genus, "Daitingopterus" David M. Unwin has also referred miscellaneous limb bones and vertebrae from the somewhat older Kimmeridge Clay of Dorset, England to the genus; these finds at the time marked the earliest appearance of short-tailed pterosaurs in the fossil record. Bennett suggested in 1996 that Germanodactylus represented adults of Pterodactylus, but this has been rejected by further studies, including his own. Bennett's 2006 reappraisal of Germanodactylus found both species to be valid and included within the genus, with G. cristatus known from four specimens including two juveniles, and G. rhamphastinus from two specimens. The genus differs from other pterosaurs by a combination of characteristics including a sharply pointed jaw tip, 4-5 premaxillary teeth and 8-12 maxillary teeth per side of the upper jaw, robust maxillary teeth that, unlike in Pterodactylus, are not reduced in size farther from the tip of the jaw, a naso-antorbital fenestra twice the length of the eye socket, and various proportional differences. G. cristatus differs from G. rhampastinus by having no teeth in the tip of the jaw and fewer teeth (~13 in each side of the upper jaw and ~12 in the lower versus 16 upper and 15 lower on each side for G. rhamphastinus). Dsungaripteroidea is a group of pterosaurs within the suborder Pterodactyloidea. The earliest known fossils attributed to this group are from the Kimmeridgian-age Upper Jurassic Argiles d'Octeville Formation of France, dated to around 155 million years ago, and belonging to the species Normannognathus wellnhoferi. The last known dsungaripteroid species is Lonchognathosaurus acutirostris, from the Albian-age Lower Cretaceous Lianmuqin Formation of Xinjiang, China, about 112 million years ago.
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Tags: Вымершие рептилии, Юра, авеметатарзалии, аждархойды, архозавроморфы, архозавры, джунгариптероиды, диапсиды, монофенестраты, орнитохейройды, птеродактили, птерозавры |
| May 15th, 2012 | |
| 08:38 pm [industrialterro] [Link] |
Dermodactylus Dermodactylus (meaning "skin finger", from Greek derma and daktylos, in reference to pterosaur wings being skin membranes supported by the ring fingers) was a genus of pterodactyloid (general term for "short-tailed" pterosaur) pterosaur from the Kimmeridgian-Tithonian-age Upper Jurassic Morrison Formation of Wyoming, USA. It is based on a single partial bone, from the hand. Dermodactylus is based on YPM 2000, a distal right fourth metacarpal found by Samuel Wendell Williston at Como Bluff. This bone constituted at the time the oldest pterosaur remains found, recognized, and described from North America. Othniel Charles Marsh first named it as a species of Pterodactylus: P. montanus, the specific name meaning "from the mountains" in Latin, but soon changed his mind and gave it a new generic name. At the same time he assigned another wing bone, teeth, vertebrae, and a scapulacoracoid to it, but this material is probably too large to belong to the type individual. Its place within the Pterosauria is uncertain, beyond the Pterodactyloidea. The material it is based on is too meager for further classification (although Carpenter et al.. [2003] note that the shape of the bone's articular end means that it did not belong to an ornithocheirid, a type of short-tailed pterosaur that often had a head crest and/or large teeth), or for adding additional remains to the genus with any certainty, and so it is now regarded as a dubious pterodactyloid. It was not even mentioned in the most recent major popular work on pterosaurs. Marsh suggested it had a wingspan of 1.5-1.8 meters (5-6 feet), but this is including the material excluded by Peter Wellnhofer, who estimates the wingspan of the only known individual at 1 meter (3.28 feet). John Foster estimates its weight at 3.3 kilograms (7.3 pounds). It would probably have been a small aerial carnivore. Птерода́ктили (Pterodactyloidea, от греч. πτερόν — «крыло» и δάκτυλος — «палец») — подотряд вымерших рептилий отряда летающих ящеров (птерозавров), живших в юрском и меловом периодах. Высокоспециализированная группа, приспособившаяся к жизни в воздухе. Для птеродактилей характерен сильно удлинённый лёгкий череп. Зубы немногочисленные и мелкие; чаще они отсутствовали. Шейные позвонки вытянутые, без шейных рёбер. Крылья мощные, широкие; летательные пальцы складывающиеся. Хвост очень короткий. Кости голени сращенные. Размеры птеродактилей сильно варьировали — от мелких, величиной с воробья, до гигантских птеранодонов с размахом крыльев до 8 метров, орнитохейрусов и аждархид (кецалькоатль, арамбургиана) с размахом крыльев до 12 метров. Мелкие питались насекомыми, крупные — рыбой и др. водными животными. Останки птеродактилей известны из верхнеюрских и меловых отложений Западной Европы, Восточной Африки и обеих Америк, Австралии, в России — Поволжья. На берегах Волги впервые останки птеродактиля обнаружены в 2005 году. Самый крупный птеродактиль был обнаружен в Румынии в местечке Себеш уезда Алба; размах его крыльев - 16 м. Отряд включает в себя ряд семейств: Istiodactylidae — семейство, представители которого обитали в юрском и меловом периодах. Все находки данного семейства сделаны в северном полушарии - Северной Америке, Европе и Азии. В 2011 году был описан новый вид Gwawinapterus beardi отнесенный в данное семейство. Он был найден на территории Канады в меловых отложениях датируемых концом мелового периода (75 млн лет назад). Pteranodontidae семейство больших птерозавров мелового периода живших в Северной Америке и Европе. Данное семейство включает следующие роды: Bogolubovia, Nyctosaurus, Pteranodon, Ornithostoma, Muzquizopteryx. Останки Ornithostoma, являющегося самым древним представителем семейства, были найдены в Великобритании. Tapejaridae известны по находкам из Китая и Бразилии времен раннего мелового периода. Azhdarchidae (от Ajdarxo, имя дракона в персидской мифологии, полученных от старого персидского Azi Dahaka) представляет собой семейство птерозавров, известное, прежде всего, с конца мелового периода, хотя ряд изолированных позвонков принадлежавших животным, относящимся к этой группе, известны и из раннего мела (140 млн. лет назад). Включает в себя некоторых представителей, являющихся самыми большими из известных летающих животных известных науке. В 2003 году D. M. Unwin определил птеродактилей как группа включающая Pteranodon longiceps, Quetzalcoatlus northropi, их последний общий предок и все его потомки.
Tags: Вымершие рептилии, Юра, авеметатарзалии, архозавроморфы, архозавры, диапсиды, монофенестраты, птеродактили, птерозавры |
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