Source by: Phys.org
Dinosaurs were in different shapes and sizes and most definitely, belonged to different genus and families. In this article, we will take a closer look at the members of the ornithischian family Hadrosauridae; The Duck-Billed Dinosaurs, or Hadrosaurs.
It is a sight to see when we unravel the different types of Dinosaurs with all the unusual anatomical features they possess. Especially the Duck-Billed Dinosaur.
Also known as the Hadrosaurids, these beautiful beasts possessed flattened rostral bones in their snouts, giving them the unique appearance, similar to a duck’s bill, that they are known for today for carrying out various types of beneficial tasks such as defense and felling trees.
However, their duckbill is not the only exciting peculiar thing about these dinosaurs, and these features are particular to a few dinosaurs. Let’s take a brief look at some other special features of theirs before we dive deep into what various types there were.
Some Fun Facts About Duck-Billed Dinosaurs
Source by: University of Toronto
Dicing Dentition
Duck-billed Dinosaurs were one of the most prevalent herbivores (Plant-eating Dinosaurs) during the Late Cretaceous era in Asia and North America, and also in the tail-end of several lineages in the Cretaceous period scattered into Africa, Antarctica, Europe, and South America. Their diet was suggested to have consisted mainly of complex substances like twigs and stems, based on research carried out by Paleontologists Mark Purnell, Vincent Williams, and Paul Barrett.
Hence, the plants were not easily masticated, but the hadrosaur teeth functioned with such high efficiency due to their properly-arranged anatomy. Each row of hadrosaur teeth contained about 45-60 teeth, with some dinosaur species possessing as many as six rows in the mouth. In addition to that, these dinosaurs didn’t have permanent teeth! I.e., Old teeth that fell out were replaced by new ones. Quite amazing.
Special egg-care
Hadrosaurs migrated to nesting grounds on dry land to lay their eggs even though they spent most of their daytime close to water. It’s assumed that they covered their nest with vegetation, which would ferment, producing heat and keeping the eggs warm as a result. Hadrosaur egg fossils have been collected, preserved, and studied by paleontologists around the world, as well as fossils of young hadrosaurs, bones from the skull, and front legs of the duck-billed dinosaurs.
Unmatched Limbs
It’s a wonder a know that the limbs and pelvis of juvenile hadrosaurs were similar in anatomy and proportion to those of the adult animals. Research suggests that young hadrosaurs walked only on their two hind legs while adults walked on all four. As the Dinosaur aged, the front legs became more robust to bear the weight of the animal, while the back legs reduced in size as they transitioned to walking on four limbs.
Furthermore, their front legs were shorter than their back limbs. They must have been such amazing sight to see, as they were giant animals.
With these facts in mind, We can now dive into the various classes of duck-billed Dinosaurs.
Types of Duck-billed dinosaurs
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Now that we are done with some interesting facts about duck-billed dinosaurs let’s go back in time to the early cretaceous period and talk about some of them.
Two major subfamilies have been recognized, both of which had peculiar jaws that look very similar to a duck’s bill, namely: The subfamily Lambeosaurinae possesses a hollow-crest and the subfamily Saurolophinae, historically known as Hadrosauridae. Both of these have been robustly supported in all recent literature.
Lambeosaurines have also been traditionally split into Parasaurolophini and Lambeosaurini. Recently, Tsintaosaurini and Aralosaurini have also been discovered.
The Hollow-Crested Hadrosaurids
Source by: En.wikipedia.org
The Hollow-Crested Hadrosaurids or Lambeosaurinae are the first subfamily of duck-billed Hadrosaurids. This class of Dinosaurs possesses a conspicuous head crest above their head, making them peculiar and easy to identify. This family also consists of more than ten recognized subgroups.
The prominent crest of the Lamb5eosaurine had hollow air chambers that many paleontologists suggest as part of nasal passages, used to produce sounds, and simultaneously serves as a visual display of some sort. It was also believed that these crests were used to breathe fire, but this opinion has been scientifically dismissed.
This is opposed to the sister subfamily Saurolophinae which had solid crests or no crest. The two major species worthy of note in the Lambeosaurinae subfamily are Parasaurolophus and Lambeosaurus.
Parasaurolophus
Source by: Onlydinosaurs
The first duck-billed dinosaur is one of the famous hadrosaurid dinosaurs, Parasaurolophus. With its large crest as a distinguishing feature, this dinosaur is estimated to have reached 9.5m(31ft) and a weight of 2.8 tonnes. This duck-billed dinosaur lived in the Asian and North American regions during the Late Cretaceous. Research into the lifestyle of these Dinosaurs suggests that their crests were used either as weapons against predators or as a way to communicate with each other like a horn.
These are only suggestions from scientists based on research, revealing that they were social animals, herding together with other herbivore dinosaurs.
Lambeosaurus
Source by: Path-of-titans.fandom
This species also possessed a prominent hollow crest used for display and communication amongst themselves. Like all Hadrosaurs, their beak had the duck-billed shape, they were plant-eaters, and they walked on hind legs and forelegs when grazing.
They are late-Cretaceous Hadrosaurs, with their fossils found in China, Russia, North America, and Europe.
Corythosaurus
Source by: DK Find Out
A large plant-eating Dinosaur that lived in the late Cretaceous period. Its name means “Helmet Lizard.” Just like other duck-billed Dinosaurs, Corythosaurus has large numbers of teeth, in this case, behind its jaws, which it uses to crush plant matter. Its bony crest contained a nasal passage and might have been a communication device. Different skeletons of Corythosaurus have belonged to about seven different species. Only one species is, however, recognized currently because a comparison of more than 20 skulls has proved that the crest changes as it grows larger.
Tsintaosaurus
Source by: Jurassicworld-evolution.fandom
The next crested hadrosaurid is the Tsintaosaurus. Tsintaosaurus lived during the Late Cretaceous Period some 83.6 million years ago – 72.1 million years ago. For Tsintosaurus, the most distinctive feature has to be its unique head crest which once earned it the nickname of the “unicorn dinosaur.”
Tsintaosaurus is unlocked on Isla Tacaño, and like other hadrosaurs, it is relatively easy to manage, provided that their social needs are accommodated.
Like other hadrosaurs had such as a toothless beak and batteries of grinding teeth at the back of its jaws, Titanosaurus is a herding animal that needs to be kept in groups of four or more be comfortable.
It is tolerant of other herbivores, tolerating up to twenty-two other dinosaurs of various species—a similar requirement to other hadrosaurs such as Corythosaurus and Parasaurolophus.
Velafrons
Source by: National Geographic
Velafrons (meaning “sailed forehead”) is Late cretaceous hadrosaur. It belongs to the genus lambeosaurine hadrosaurid dinosaur that roamed the earth some 72 million years ago. It is known from a mostly complete skull and partial skeleton of a juvenile individual, with a bony crest on the forehead.
It was found in the late Campanian-age Upper Cretaceous Cerro del Pueblo Formation (about 72 million years old) near Rincon Colorado, Coahuila, Mexico. The type specimen is CPC-59, and the type species is V. coahuilensis.
In comparison with other genera, Velafrons had a large skull that only a few dinosaurs had at a similar growth stage, so the crest may have been small in adults or followed a different growth pattern, or it may be that adult Velafrons were also larger than adults of other lambeosaurine genera.
Unusually large size is also seen in the Mexican hadrosaurids Kritosaurus sp. and Magnapaulia laticaudus. As a hadrosaurid, Velafrons would have been an herbivore.
Other duck-billed dinosaurs Lambeosaurine species are Charonosaurus, Corythosaurus, Magnapaulia, Pararhabdodon.
The Non-Crested Hadrosaurids
Source by: CNET
These are the Saurolophinae Hadrosaurids which generally possessed no crests. Although certain species of this subfamily have spines, they are not hollow like in the first subfamily and are differently shaped. The species with solid ridges are well-equipped for danger, to protect, and to attack.
This subfamily included Maiasaura, Shantungosaurus, and Edmontosaurus, which lacked crests on their skull.
Maiasaura
Source by: Jurassicworld-evolution.fandom
Maiasaura were large herbivores, reaching a known height of 9 meters (30ft). Their beaks were flat, which is a characteristic of hadrosaurids. They could walk on both two feet (bipedal) and four feet (quadrupedal). The juveniles under four years utilized only their hind legs and transitioned into a quadrupedal walking mode as they grew larger.
This class of Hadrosaurids, as stated earlier, possessed no crests. Thus, they did not have many defensive features. However, they had muscular tails, which were very useful for defense. It has also been suggested that the large sizes of their herds served as a means of protection. Their herds were huge, consisting of up to 10,000 Dinosaurs.
Shantungosaurus
Source by: Britannica
This group is unique because it contains a single species, Shantungosaurus giganteus. They have been identified as the largest(in size) hadrosauroid taxon in the world, with their femur being as long as 1.7 meters (5.6 ft). They lived in the Late Cretaceous period, some 100.5 million years ago – 66 million years ago, and were discovered in the Wangshi group of the Shandong Peninsula in China. They could also weigh up to 16 tonnes, and they had jaws packed with about 1500 tiny chewing teeth. They could make sounds by inflating a loose flap of skin covering a large hole near the nostrils.
Edmontosaurus
Source by: Dino.fandom
This hadrosaurid genus contains two known species: Edmontosaurus regalis and Edmontosaurus annectens. The edmontosaurus specimen were discovered in rocks of western North America that dates from the late Campanian stage of the Cretaceous Period 73 million years ago, and those of E. annectens were found in rocks that date to the end of the Maastrichtian stage of the Cretaceous Period.
Edmontosaurus had Dinosaurs that were also very large, with their height reaching 12 meters (39ft) and weight reaching about 4.0 metric tons. They were the last non-avian (non-bird) Dinosaurs. Research suggests that they lived in herds and might have been migratory.
Aquilarhinus
Source by: ARK News
Aquilarhinus (which means “eagle snout”) is a genus of duckbilled Dinosaurs from the Aguja Formation, Texas, in the United States. It was inferred to have had shovel-billed beak anatomy, which was somewhat different from other hadrosaurs. This was said to its unusual dentition. The only species discovered in this group is the Aquilarhinus payments.
Aquilarhinus may have a different feeding method from other hadrosaurs, focusing on one particular type of plant.
Gryposaurus
Source by: Images.squarespace-cdn
Gryposaurus (meaning “hooked-nosed (Greek grapes) lizard”; sometimes incorrectly translated as “griffin (Latin gryphus) lizard”) was a genus of duckbilled dinosaur that lived about 83 to 74 million years ago, in the Late Cretaceous period (late Santonian to late Campanian stages) of North America.
Gryposaurus is based on specimen NMC 2278, a skull and partial skeleton collected in 1913 by George F. Sternberg from what is now known as the Dinosaur Park Formation of Alberta, along the Red Deer River. This specimen was described and named by Lawrence Lambe shortly after that, Lambe drawing attention to its prominent crest. In fact, the distinctive crest was particularly unusual.
There are three species of Gryposaurus named, and research is still ongoing on discovering new species. The three named species of Gryposaurus differ in details of the skull and lower jaw. The prominent nasal arch found in this genus is formed from the paired nasal bones.
In profile view, they rise into a rounded hump in front of the eyes, reaching a height as tall as the highest point of the back of the skull. The skeleton is known in great detail, making it a useful reference point for other duckbill skeletons.
Speaking of the unique nasal arch of Gryposaurus, like other cranial modifications in duckbills, it may have been used for a variety of social functions, such as identification of sexes or species and social ranking.
It could also have functioned as a tool for broadside pushing or butting in social contests, and there may have been inflatable air sacs flanking it for both visual and auditory signaling. Gryposaurus was a herbivore and laid eggs.
Brachylophosaurus
Source by: Fandom
Brachylophosaurus, meaning a short-crested lizard, was a member of the hadrosaur genera. It is known from several skeletons and bonebed material from the Judith River Formation of Montana and the Oldman Formation of Alberta, living about 78 million years ago.
The most distinct feature of the Brachylophosaurus is its bony crest, which forms a horizontally flat, paddle-like plate over the top of the rear skull. Some individuals, depending on their age, had crests that covered nearly the entire skull roof, while others had shorter, narrower crests.
Many paleontologists and scientists have suggested that the crest was used for pushing contests, but it may not have been strong enough for this. Other notable features are a relatively small head, the unusually long lower arms, and the beak of the upper jaw being wider than with other contemporary hadrosaurs.
Like other hadrosaurs, Brachylophosaurus possessed features like cheeks to keep fodder in the mouth and dental batteries consisting of hundreds of stacked teeth. These teeth could be used to chew efficiently, a feature rare among reptiles but common among some cerapodan ornithischian dinosaurs like Brachylophosaurus.
Saurolophus
Source by: DeviantArt
Finally, on the Ornithopod dinosaurs is the Saurolophus. Like most hadrosaurs, it belongs to the genus of large saurolophine hadrosaurid dinosaurs that lived about 70.0–68.5 million years ago, in the Late Cretaceous of North America and Asia; it is one of the few genera of dinosaurs known from multiple continents.
It is distinguished by a spike-like crest that projects up and back from the skull. Saurolophus was a herbivorous dinosaur that could move about either two legs or all four legs.
The most distinctive feature of Saurolophus is its cranial crest, which is present in young individuals but is smaller. This crest is often described as solid but appears to be solid only at the point, with internal chambers that may have had a respiratory and heat-regulation function.
Saurolophus fossils have been found in rocks of early Maastrichtian age, in the Upper Cretaceous Horseshoe Canyon Formation (then known as the Edmonton Formation) near Tolman Ferry on the Red Deer River in Alberta.
The discovery, fossils, is now on display in the American Museum of Natural History; this skeleton was the first nearly complete dinosaur skeleton from Canada.
Other non-crested hadrosaurs include Sercenosaurus.
Basal Hadrosaurs
Source by: EurekAlert
This group of hadrosaurs do not fall under either subfamily of the duck-billed dinosaurs but belong to the Hadrosauridae family because they possess all the common features, as well as the rostral duckbill bones. Researchers believe that they also have a common ancestry with the family.
The term ‘Basal’ in biological terms has to do with being ancestral. Thus, they are the oldest members of the entire duck-billed Dinosaurs. The most prominent member of this group happened to be the first to be discovered in North America, the Hadrosaurus foulkii.
That’s a wrap on the shortlist of dinosaurs called ornithopods, or if you will, duck-billed dinosaurs. That’s not all there is to Duck-Billed dinosaurs. But, we are sure you have learned a few things.
Also, the animatronic products of all the discussed dinosaurs are available. Be sure to check them out and for other Dinosaurs not addressed in the article.
