Scleromochlus is an extinct genus of small avemetatarsalian from the Late Triassic period. A lightly built cursorial animal, its phylogenetic position has been debated; as different analyses have found it to be either the basal-most ornithodiran, the sister-taxon to Pterosauria, or a basal member of Avemetatarsalia that lies outside of Ornithodira.

 Scleromochlus is a monotypic genus (single species), which is the type species S. taylori.

 Scleromochlus taylori was about 181 mm (about 7.1 inches) long, with long hind legs; it may have been capable of four-legged and two-legged locomotion.

 Its fossils have been found in the Carnian Lossiemouth Sandstone of Scotland. The holotype is BMNH R3556, a partial skeleton preserved as an impression in sandstone; part of the skull and tail are missing.

 Птероза́вры (Pterosauria — «летающие ящеры») — отряд вымерших летающих архозавров. Жили в мезозое на протяжении более 200 млн лет. Последние представители относятся ко времени вымирания динозавров, около 65 млн лет назад.

 В середине XVIII в. учёные извлекли из юрских зольнхофенских известняков (Бавария, Германия) несколько полных скелетов небольшого животного. Это существо настолько отличалось от всех современных животных, что долгие годы учёные терялись в догадках, что это за животное. Одни сочли его неведомой уткой, другие — летучей мышью и даже миниатюрным драконом. И только в 1809 году великий французский зоолог и палеонтолог Жорж Кювье окончательно установил, что найденные скелеты принадлежали вымершей летающей рептилии. Кювье назвал её птеродактилем («пальцекрыл»).

 Позднее, в XIX веке вокруг птерозавров развернулась ещё одна дискуссия. Ведущие британские учёные того времени Ричард Оуэн и Гарри Сили спорили о том, были ли птерозавры холоднокровными рептилиями или теплокровными «примитивными птицами». Картину прояснили последующие ископаемые находки. Без сомнения, птерозавры являлись рептилиями (как и полагал Оуэн), но теплокровными.

 Размах крыльев птерозавров достигал 7 метров, что более чем вдвое превышает этот показатель у любой из ныне живущих птиц.

 Их крылья представляли собой складки кожи, натянутые между боками тела и очень длинным четвёртым пальцем передних конечностей. Скелет обладал облегченной конструкцией: тонкие полые кости, лёгкий череп почти что сетчатой структуры, грудина имела киль, как у птиц. Строение скелета крыльев и плечевого пояса указывает на наличие мощной махательной мускулатуры. Необходимость в полёте возникла в связи с питанием рыбой и трупами, плавающими в воде, но птерозавры питались также и насекомыми. В настоящее время споры о способности птерозавров летать не утихают. Одни специалисты полагают, что гигантские рептилии могли преодолевать огромные расстояния по воздуху, а другие утверждают, что если и могли, то лишь в тихую погоду. На полуводный образ жизни указывают перепончатые лапы.

 Вытянутые в клюв челюсти могли нести зубы. У некоторых поздних форм, например, птеранодонов, были беззубые челюсти. Зубы некоторых видов свидетельствуют о питании планктоном.

 Птерозавры имели достаточно хорошо развитый мозг (преимущественно за счет мозжечка, отвечающего за координацию движений) и острое зрение. У них были редуцированны (уменьшены) обонятельные доли и развиты зрительные доли, что говорит о том, что летучих ящеров больше интересовало, как что-то выглядело, нежели как оно пахло. Тело было покрыто своеобразной «шерстью», что позволяет делать предположения о теплокровности птерозавров. На теплокровность указывает и обильное кровоснабжение костей, подобное тому, что наблюдается у птиц и млекопитающих. Возможно, что «шерсть» — это «пуховое оперение» молодых животных, так как у многих видов (например, Eudimorphodon) следы власоподобных структур обнаружены только на останках молодых особей. Птерозаврам для целей минимизации проблем с терморегуляцией при полноценном бодрствовании в светлое время суток просто необходимо было иметь многослойную, сложно устроенную мембрану крыла с развитой сосудистой сетью, обеспечивающей кондиционирование, а также наружные покровы, способные защитить от попадания избыточного количества прямых и отражённых солнечных лучей (например, во время полётов над водой), и гарантировать доставку крови к голове одной и той же температуры.

 По причине высокой специализации анатомии птерозавров для полета и отсутствия на данный момент известных переходных эволюционных форм, предки этих рептилий до конца не понятны. По некоторым гипотезам, они происходят от орнитодир, таких как Scleromochlus, относящихся к Avemetatarsalia близких к эупаркерии или же от проторозавров (особенно примечательным в этом предположении является вид шаровиптерикс).

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 Austriadactylus is a genus of "rhamphorhynchoid" pterosaur. The fossil remains were unearthed in Late Triassic rocks of Austria.

 The genus was named in 2002 by Fabio Marco Dalla Vecchia e.a.. The type species is Austriadactylus cristatus. The genus name is derived from Latin Austria and Greek daktylos, "finger", in reference to the wing finger of pterosaurs. The specific epithet means "crested" in Latin, a reference to the skull crest.

 The genus is based on holotype SMNS 56342, a crushed partial skeleton on a slab, found in an abandoned mine near Ankerschlag in Tirol, in the Norian Seefelder Beds. The counterslab has been lost and with it some of the bone. The fossil consists of the skull, lower jaws, some vertebrae, parts of the limbs and pelvic girdle, and the first part of the tail.

 The elongated skull has a length of eleven centimetres. It carried a bony crest that widened as it descended towards the snout, up to height of two centimetres. The triangular nares formed the largest skull openings. The also triangular fenestrae antorbitales are smaller that the orbits. The teeth differ in shape and the species was thus heterodont. Most teeth are small and tricuspid or three-pointed. In the front of the upper jaw five larger recurved teeth with a single point form a prey grab; six or seven such teeth are also interspersed with the smaller teeth more to the back of the mouth. There are at least seventeen and perhaps as much as 25 tricuspid teeth in the upper jaw, for a total of perhaps 74 teeth of all sizes in the skull. The number of teeth in the lower jaws cannot be determined.

 The flexible tail did not have the stiffening rod-like vertebral extensions present in other basal pterosaurs. The wingspan has been estimated at about 120 centimetres.

 Austriadactylus was in 2002 assigned by the describers to a general Pterosauria incertae sedis, but some later analyses showed it to have been related to Campylognathoides and Eudimorphodon in the Campylognathoididae. It has even been suggested it was a junior synonym of Eudimorphodon, though perhaps a distinct species in that genus.

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 Caviramus is a genus of "rhamphorhynchoid" pterosaur from the Late Triassic (late Norian-early Rhaetian-age) lower Kössen Formation of the Northern Calcareous Alps of Switzerland.

 The genus was in 2006 named by Nadia Fröbisch and Jörg Fröbisch. The type species is Caviramus schesaplanensis. The genus name is derived from Latin cavus, "hollow" and ramus, "branch". The specific name refers to Mount Schesaplana.

 The genus is based on holotype PIMUZ A/III 1225, three non-contiguous fragments of a ramus (lower jaw) of the mandible with multicuspate teeth. Two teeth are preserved, one with three cusps, and one with four; despite this difference the authors consider them as essentially isodont. The number of teeth is estimated at a minimum of twelve and a maximum of seventeen. A row of large oval foramina runs parallel to the tooth row; foramina in the form of small holes in the anterior part of the lower jaw suggest some sort of soft-tissue structure, or a keratin covering. The jaw is light and hollow. The teeth of this genus resemble those of Eudimorphodon, but the jaw is different. The discovery of this genus is a find of some significance, as there are few pterosaurs known from the Triassic.

 A second specimen, originally assigned to its own genus and species as Raeticodactylus filisurensis, consists of a single disarticulated partial skeleton including an almost complete skull. The skull shows that it had a tall thin bony crest running along the midline of the front of the upper jaw, and a keel on the lower jaw. The teeth at the front of the upper jaw, in the premaxillae, were fanglike, whereas the teeth in the upper cheeks (the maxillae) had three, four, or five cusps, similar to those of Eudimorphodon. Caviramus had a wingspan of about 135 centimeters (53 in), and may have been a piscivore, potentially a dip-feeder.

 Despite the resemblance to Eudimorphodon the authors classified Caviramus as Pterosauria incertae sedis. A 2009 study by Fabio Dalla Vecchia concluded that Raeticodactylus, which is known from a more complete skeleton including lower jaw, probably belong to the same genus, and possibly the same species, if the differences (such as size and the presence of a crest in the Raeticodactylus specimen) are not due to sex or age. Subsequent studies have supported their synonymy. Dalla Vecchia found the two forms in a sister clade of Carniadactylus, implying that Caviramus was a member of the Campylognathoididae.

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 Eudimorphodon was a pterosaur that was discovered in 1973 by Mario Pandolfi near Bergamo, Italy and described the same year by Rocco Zambelli. The nearly complete skeleton was retrieved from shale deposited during the Late Triassic (mid to late Norian stage), making Eudimorphodon the oldest pterosaur then known. It had a wingspan of about 100 centimetres (3.3 ft) and at the end of its long bony tail may have been a diamond-shaped flap like in the later Rhamphorhynchus. If so, the flap may have helped it steer while maneuvering in the air. Eudimorphodon is known from several skeletons, including juvenile specimens.

 Eudimorphodon showed a strong differentiation of the teeth, hence its name, which is derived from ancient Greek for "true dimorphic tooth". It also possessed a large number of these teeth, a total of 110 of them densely packed into a jaw only six centimeters long. The front of the jaw was filled with fangs, per side four in the upper jaw, two in the lower jaw, that rather abruptly gave way to a line of smaller multipointed teeth, 25 in the upper jaw, 26 in the lower jaw, most of which had five cusps, others three or even four.

 The morphology of the teeth are suggestive of a piscivorous diet, which has been confirmed by preserved stomach contents containing the remains of fish of the genus Parapholidophorus. Young Eudimorphodon had slightly differing dentition with fewer teeth and may have had a more insectivorous diet. The top and bottom teeth of Eudimorphodon came into direct contact with each other when the jaws were closed, especially at the back of the jaw. This degree of dental occlusion is the strongest known among pterosaurs. The teeth were multi-cusped, and tooth wear shows that Eudimorphodon was able to crush or chew its food to some degree. Wear along the sides of these teeth suggests that Eudimorphodon also fed on hard-shelled invertebrates.

 Despite its great age Eudimorphodon has few primitive characteristics making the taxon of little use in attempting to ascertain where pterosaurs fit in the reptile family tree. Basal traits though, are the retention of pterygoid teeth and the flexibility of the tail, which lacks the very long stiffening vertebral extensions other long-tailed pterosaurs possess. Paucity of early pterosaur remains has ensured that their evolutionary origins continues to be a persiseant mystery with some experts suggesting affinities to dinosaurs, archosauriformes, or prolacertiformes.

 Within the standard hypothesis that the Dinosauromorpha are the pterosaurs' close relatives within an overarching Ornithodira, Eudimorphodon is also unhelpful in establishing relationships within Pterosauria between early and later forms because then its multicusped teeth should be considered highly derived, compared to the simpler single-cusped teeth of Jurassic pterosaurs, and a strong indicator that Eudimorphodon is not closely related to the ancestor of later pterosaurs. Instead it is believed to be a member of a specialized off branch from the main "line" of pterosaur evolution, the Campylognathoididae.

 Eudimorphodon currently includes two species. The type species, E. ranzii, was first described by Zambelli in 1973. It is based on holotype MCSNB 2888. The specific name honours Professor Silvio Ranzi. A second species, E. rosenfeldi, was named by Dalla Vecchia in 1995 for two specimens found in Italy. However, further study by Dalla Vecchia found that these actually represented a distinct genus, which he named Carniadactylus in 2009. One additional species is still currently recognized: E. cromptonellus, described by Jenkins and colleagues in 2001. It is based on a juvenile specimen with a wing span of just 24 centimeters, MGUH VP 3393, found in the early nineties in Greenland. Its specific name honors Professor Alfred W. Crompton; the name is a diminutive because the exemplar is so small.

 In 1986 fossil jaw fragments containing multicusped teeth were found in Dockum Group rocks in western Texas. One fragment, apparently from a lower jaw, contained two teeth, each with five cusps. Another fragment, from an upper jaw, also contained several multi-cusped teeth. These finds are very similar to Eudimorphodon and may be attributable to this genus, although without better fossil remains it is impossible to be sure.

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