Pterodactyls
Pterodactyls History
Pterodactyls are known from the late Jurassic period through late Cretaceous periods about 145 million to 65 million years ago. They are informal term for a subgroup of flying reptiles known as Pterosauria. Pterodactyl is the collective term for the winged reptiles properly called pterosaurs, which belong to the taxonomic order Pterosauria. Scientists typically avoid using the name and concentrate on individual genera, such as Pterodactylus and Pteranodon. Pterodactyls are a type of Pterosaur, a broader group of flying reptiles that went extinct 66 million years ago. Because pterodactyl bones are so fragile, little is known about the origins of the ancient dinosaur relative, which eventually evolved into the biggest creature ever to take wing.
There are at least 130 valid pterosaur genera1, according to David Hone, a palaeontologist at the Queen Mary University of London. They were widespread and lived in numerous locations across the globe, from China to Germany to the Americas. The oldest known Pterodactyl has been unearthed in China, pushing back the evolution of the ancient flying reptile by five million years.
The skull of the Pterodactyl has a very bird-like appearance. However, its intimate structure more resembles that of a lizard, The possession of teeth, which at one time was thought to be an unbird-like character, we now know to be also distinctive of the American Cretaceous birds. Upon the sides of the PterodactyI skull, three vacuities are seen, namely, the orbit, the nasal aperture, and, between these, a third, known as the preorbital fossa.
Pterodactyls Physical characteristics
Pterodactyls are a subgroup of flying reptiles known as Pterosauria. Given a large number of different types of pterosaurs, the physical characteristics of the winged reptiles varied widely depending on the genera. Pterosaurs often had long necks, which sometimes had throat pouches similar to pelicans’ for catching fish. Most pterosaur skulls were long and full of needlelike teeth. However, pterosaurs of the taxonomic family Azhdarchidae, which ruled the Late Cretaceous skies and included Quetzalcoatlus northropi, were toothless. A distinguishing feature of pterosaurs was the crest on their heads. Though it was initially thought that pterosaurs had no ridges, it’s now known that ridges were widespread across pterosaur genera and came in various forms.
For instance, some pterosaurs had prominent, bony crests, while other ridges were fleshy with no underlying bone. Some pterosaurs even appear to have had a saillike crest made up of a membrane sheet connecting two large bones on the head. Pterosaur crests had all kinds of bone and flesh combinations. Over the years, scientists have proposed diverse potential purposes for these crests, including that they were used for heat regulation or to serve as rudders during flight. Crests aren’t effective rudders, and many small pterosaurs have crests even though they wouldn’t have needed them to dissipate heat. What seems most likely is that the crests were used for sexual selection. There are several lines of evidence that support this function of the crests, perhaps most notably that juveniles, which look like miniature versions of adult pterosaurs, don’t have crests, suggesting the structures are used for something only relevant to adults, such as mating.
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 multiple methods to measure growth curves among known specimens have suggested that there is only one valid Pterodactylus species, P. antiquus. The youngest immature Pterodactylus antiquus specimens alternately interpreted as young specimens of the distinct species P. Kochi have a small number of teeth as few as 15, and the teeth have a relatively broad base. The teeth of other P. antiquus specimens are both narrower and more numerous up to 90 teeth are present in some samples.
Pterodactylus specimens can be divided into two distinct year classes. In the first-year class, the skulls are only 15 to 45mm in length. The second-year class is characterized by skulls 55 to 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, and possibly belong to a distinct genus. A third-year class is represented by specimens of the traditional P. antiquus, as well as a few isolated, large samples once assigned to P. Kochi that overlap P. antiquus in size. However, all specimens in this third-year class also show a sign of immaturity. Fully mature Pterodactylus specimens remain unknown or may have been mistakenly classified as a different genus
Are Pterodactyls Dinosaurs?
Pterodactyls are not considered to be dinosaurs. They are classified as pterosaurs because they do not have an upright stance like dinosaurs. Pterodactyls are classified as reptiles and are very closely related to dinosaurs. Pterodactyls were suited well for flying with very light hollow bones and broad leathery wings. The body was long and very thin. Pterodactyls had good eyesight which was essential for finding food. They were carnivores and ate fish and other animals caught from the oceans. They may have been scavengers on land as well. Pterodactyls lived in many parts of the world. Therefore, pterodactyls lived at the same time as the dinosaurs, but somehow, they’re not dinosaurs.
Pterosaurs are often referred to by popular media or the general public as “flying dinosaurs”, but dinosaurs are defined as the descendants of the last common ancestor of the Saurischia and Ornithischia, which excludes the pterosaurs. Pterosaurs are nonetheless more closely related to birds and other dinosaurs than to crocodiles or any other living reptile, though they are not bird ancestors. Pterosaurs are also colloquially referred to as pterodactyls, particularly in fiction and by journalists. However, technically, Pterodactyl relates only to members of the genus Pterodactylus, and more broadly to members of the suborder Pterodactyloidea of the pterosaurs. Pterosaurs had a variety of lifestyles. Traditionally seen as fish-eaters, the group is now understood to have included hunters of land animals, insectivores, fruit eaters and even predators of other pterosaurs. They reproduced through eggs, some fossils of which have been discovered.
The anatomy of pterosaurs was highly modified from their reptilian ancestors by the adaptation to flight. Pterosaur bones were hollow and air-filled, like those of birds. This provided a higher muscle attachment surface for a given skeletal weight. The bone walls were often paper-thin. They had a broad and keeled breastbone for flight muscles and an enlarged brain able to coordinate complex flying behaviour. Pterosaur skeletons often show considerable fusion. In the skull, the sutures between elements disappeared. In some later pterosaurs, the backbone over the shoulders fused into a structure known as a notarium, which served to stiffen the torso during flight and provide stable support for the shoulder blade. Likewise, the sacral vertebrae could form a single synsacrum while the pelvic bones fused also.
Despite what some people still think, modern birds didn’t descend from pterosaurs such as Pterodactylus and Pteranodon, but rather, from the small, two-legged, meat-eating dinosaurs of the Jurassic and Cretaceous periods, many of which were covered with feathers. As far as we know, Pterodactylus and Pteranodon were strictly reptilian in appearance. However, there is evidence to suggest that at least some odd pterosaur genera (such as the late Jurassic Sordes) sported hair-like growths. One of the significant differences between ancient, lizard-skinned pterosaurs and modern, feathered birds is that pterosaurs most likely walked on four legs when they were on land, compared to birds’ strictly bipedal postures. How do we know? By various analyses of Pteranodon and Pterodactylus fossilized footprints (as well as those of other pterosaurs) that have been preserved alongside ancient dinosaur track marks of the Mesozoic Era.
Classification of Pterodactyls
The genus now known as Pterodactylus was originally named Petro-Dactyle by Cuvier in 1809, though this was a typographical error, later corrected by him to Ptéro-Dactyl. In 1812, Samuel Thomas von Sömmerring named the same specimen Ornithocephalus antiquus. The genus name was revised to the current Pterodactylus by Constantine Samuel Rafinesque in 1815. Unaware of Rafinesque’s publication, Cuvier himself in 1819 again emended the genus name, but the specific name he then gave, longirostris, has to give precedence to von Soemmerring’s antiquus. In 1888 Richard Lydekker designated Pterodactylus antiquus the typePterodactylus species. The original specimen is the holotype of the genus, BSP No. AS.I.739. Hermann von Meyer, in 1830, used the name Pterodactyli to contain and other pterosaurs known at the time. This was revised to the family Pterodactylidae by Prince Charles Lucien Bonaparte in 1838. This group has more recently been given several competing definitions. Pterodactylus comes from the Greek word pterodaktulos, meaning “winged finger,” which is an apt description of its flying apparatus. The primary component of the wings of Pterodactylus and other pterosaurs were made up of a skin and muscle membrane that stretched from the animals’ highly elongated fourth fingers of the hands to the hind limbs.
The reptiles also had membranes running between the shoulders and wrists (possibly incorporating the first three fingers of the hands), and some groups of pterosaurs had the third membrane between their legs, which may have connected to or integrated a tail. Early research suggested pterosaurs were cold-blooded animals that were more suited to gliding than active flying. However, scientists later discovered that some pterosaurs, including Sordes pilosus and Jeholopterus ninchengensis, had furry coats consisting of hairlike filaments called pycnofibers, suggesting they were warm-blooded and generated their body heat.
Breeding and growth of Pterodactyls
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 type is composed of specimens over two years old. This growth pattern is similar to modern crocodilians, rather than the rapid growth of modern birds.
What did Pterodactyls eat?
Pterodactyls were carnivores, though some may have occasionally eaten fruits. What the reptiles ate depended on where they lived some species spent their lives around water, while others were more terrestrial. Terrestrial Pterodactyls ate carcasses, baby dinosaurs, lizards, eggs, insects and various other animals. They were probably reasonably active hunters of small prey. Water-loving pterosaurs ate a variety of marine life, including fish, squid, crab and other shellfish. With these animals, juveniles dominate the fossil record, Hone said. This is odd because young animals are generally those that are targeted by predators, preventing them from becoming part of the fossil record. Pterosaurs floated well, but they had poor floating postures, in which their heads rested very close to the water, if not on the water.
This suggests that aquatic pterosaurs wouldn’t spend much time on the water’s surface and would launch into the air shortly after diving for food to avoid drowning. However, young pterosaurs that don’t yet have stiff muscles or are still learning to fly would have more difficulties launching back into the air from a dive, possibly resulting in drowning. Pterodactyls most probably flew very long distances due to the different atmospheric content dense oxygen-rich atmosphere. Pterosaurs could move on the ground and needed to as to be able to take flight. For a while, scientists didn’t know if this was using two feet (bipedal) or using four feet (quadrupedal). We now know that they used four, from fossil footprints. However, we don’t know if they did this all the time. Some scientists think that small Pterosaurs could walk or even run on two feet, but larger ones used all four like bats do now.