Pachycephalosaurus

DataBase Center for Life Science (DBCLS), CC BY 4.0, via Wikimedia Commons

FURTHER READING AND STUDY

• Giffin et al., (1988). A New Pachycephalosaurid Hell Creek Formation of Montana
• Gilmore (1931). Pachycephalosaurus wyomingensis; North America; USA; Wyoming; Niobrara County
• Gilmore (1931). A new species of troodont dinosaur from the Lance Formation of Wyoming

The name Pachycephalosaurus means “thick-headed lizard” and is pronounced, “pack-i-KEF-al-oh-sore-russ.” The genus name originates from the Greek words “pachys” which means “thick,” “kephale” which means “head,” and “sauros” which means “lizard”. Pachycephalosaurus lived throughout the Cretaceous epoch and frequented North American terrestrial environments. It lasted from the Campanian through the Maastrichtian periods, and lived on Earth between 72 and 66 million years ago, according to estimates.

It is the most famous and largest of the pachycephalosaur or thick-headed dinosaurs. Pachycephalosaurus wyomingensis, the type and currently only valid species, was named in 1931. Pachycephalosaurus was one of the last non-avian dinosaurs and fossil remains have been found in Montana, South Dakota, Wyoming, and Alberta. It was a herbivorous species with a single skull and a few extraordinarily thick skull roofs that measured 9 inches thick. The fragmentary skull of the type species P. wyomingensis is documented from the Lance Formation of Niobrara County, Wyoming. The dome-shaped bony head of the Pachycephalosaurus is well-known and In recent years, more complete fossils have been discovered.

These dinosaurs were estimated to be roughly 4.5 meters long and weighed around 449 kg. They were little yet amazing, with a height comparable to that of a full-grown cow or buffalo, their massive dome-shaped heads of Pachycephalosaurus dinosaurs are well-known. Its skull’s dome-shaped component was roughly 25.4 cm thick, which effectively shielded the dinosaur’s brain. Spikes or bony knobs covered the top of their skulls and reached the tip of their noses. Their teeth were little, and their mouth was shaped like a beak, and the skulls of Pachycephalosaurus were tiny and spherical to leaf-shaped. Their eyes were large and their noses were little, and they were predominantly bipedal, according to the remains. Their legs were large and powerful, but their forearms were probably little, and it possessed five-finger claws on each hand and three clawed toes on each foot. It possessed a long, thick tail that added to its overall length.  As they were always at risk of being hunted by predators, they developed a rapid rate of movement to protect themselves.

Pachycephalosaurus were small herbivorous dinosaurs that lived in North America’s open regions, forests, and terrestrial environments. Plants, fruits, and seeds were its primary sources of nutrition. It is thought that its teeth were unable to handle some of the stronger leaves that other herbivores could, therefore the plants it ate had to be soft. However, it’s worth noting that this dinosaur may have also eaten insects. Paleontologists speculated in the 1970s that male pachycephalosaurs utilised their dome heads as battering rams, similar to bighorn sheep. Their domed cranium served as a defence mechanism against predators. The spikes or bony knobs served as deterrents as well, but they were not sharp or pointy. They are thought to have died out during the Cretaceous–Paleogene extinction catastrophe.

Pachyrhinosaurus

Nobu Tamura (http://spinops.blogspot.com), CC BY 3.0, via Wikimedia Commons

FURTHER READING AND STUDY

• Currie and Langston (2008). A new species of Pachyrhinosaurus from the Upper Cretaceous of Alberta, Canada
• Charles (1950). Pachyrhinosaurus canadensis, representing a new family of the Ceratopsia, from southern Alberta
• Langston (1967). The thick-headed ceratopsian dinosaur Pachyrhinosaurus, from the Edmonton Formation near Drumheller, Canada

Pachyrhinosaurus, which means ‘thick-nosed lizard,’ is pronounced “pack-ee-RINE-oh-sore-us.” The name of the genus comes from Greek words that indicate “pachy,” “thick nose,” and “lizard.”  Pachyrhinosaurus dinosaurs lived between 71 million and 67 million years ago, near the end of the Cretaceous Period. It lived in a canyon from the Campanian to the Maastrichtian periods.  Pachyrhinosaurus was a horned centrosaurine ceratopsid herbivorous dinosaur genus that went extinct. The type species is P. canadensis, and two more species in this genus are P. lakustai and P. perotorum. 

It was first discovered in 1946 in Alberta, Canada, was given its name in 1950, and its range included Alaska as well as Alberta. The anterior half of the skull was obtained in 1945 and 1946 from the sandy clay of the Horseshoe Canyon Formation in Alberta, Canada, but the right lower mandible and the “beak” were missing. The finding of the Pipestone Creek bone bed in the late 1980s was the most significant prehistoric animal excavation. The find yielded about 3,500 bones, as well as 14 Pachyrhinosaurus skulls, representing individuals of all ages, from full-grown adults to newborns, juveniles, and children.

Pachyrhinosaurus was a big ceratopsian quadrupedal dinosaur that weighed around 1,800 kg and measured 18 to 23 feet long. It had a large head, like other ceratopsids, with a narrow but robust beak and a bony frill. It was a four-legged herbivore with horns above its eyes and a big frill around its neck. Some of its horns grew between and slightly behind the eyes like unicorn horns, while others adorned the frill’s top border. Pachyrhinosaurus likewise had thicker bone knobs, with the largest covering the top of the nose. Pachyrhinosaurus was most likely a herd animal that travelled in vast herds and looked for its young. It was herbivorous and had a robust set of cheek teeth to aid in the chewing of tough, fibrous vegetation, furthermore, its beak was jagged. Pachyrhinosaurus could almost definitely run at speeds of up to 20 miles per hour, which would let it defend itself more effectively.

Dinosaurs lived in a region that was limited to the west by mountains and included old channels, small freshwater ponds, streams, and floodplains. With its strong, toothed beak, and its cheek teeth that were capable of chewing, Pachyrhinosaurus most likely ate cycads, palms, and other prehistoric vegetation. The knobs could have been for species recognition, male competition, or predator defense. When assaulted, the Pachyrhinosaurus will usually charge. It can also emit chemical pheromones that have an impact on nearby species, including generally docile mammals. When it is attacked, it can release a red chemical from its nostrils, which will enrage adjacent creatures and cause them to attack the creature’s attacker.

Panoplosaurus

Conty, CC BY 3.0, via Wikimedia Commons

FURTHER READING AND STUDY

• Lambe (1919). Description of a new genus and species (Panoplosaurus mirus) of an armored dinosaur from the Belly River Beds of Alberta
• Sternberg (1921). A supplementary study of Panoplosaurus mirus
• Carpenter (1990). Ankylosaur systematics: example using Panoplosaurus and Edmontonia

Panoplosaurus is pronounced “pan-op-loh-sore-us,” and its name is derived from the Greek hoplon, which means “well-armored lizard.” It was given its name in 1919. It lived during the Cretaceous epoch and roamed North America’s terrestrial areas 66 million years ago. They appear to have lived on coastal plain flatlands near old mid-continental seaways in western North America, and during the Late Cretaceous Period, this armoured dinosaur was one of the last of the Nodosaurids to be discovered. 

Panoplosaurus dinosaurs are part of the nodosaur family of armoured dinosaurs with Edmontonia and Panoplosaurus appearing to be closely related. The genus Panoplosaurus contains only one species, Panoplosaurus mirus. Its fossils have been discovered in Alberta, Coahuila, and Montana, with Panoplosaurus only being known from two partial skeletons, one of which still has remnants of its original armour. A nearly complete skull in articulation, most or all of the cervical vertebrae, front dorsal vertebrae, a majority of the disarticulated forelimb, three articulated fingers, a fragment of the pelvis, partial sacrum, a few bones of the foot, hundreds of osteoderms, and dermal ossicles were discovered 4.43 km south of the mouth of the Little Sandhill tributary of the Red Deer River.

Panoplosaurus measured 5 to 7 meters in length, stood 2 meters tall, and weighed 1.5 to 1.6 tons. Panoplosarus was a herbivorous animal with thick armor, with its back and tail most likely covered in traverse bands of studded plates. The tail, however, lacked the club found in other ankylosaurids, the shoulders, neck, and front limbs were all clad in bone armor.

The outer surface of this armour was designed with a pronounced curving ridge. A helmet-like shield adorned the top of the head, and cutes of bone were also discovered on the cheeks. There was also believed to possess a short and wide back cranium, and the snout was especially slender. The coracoid was thin and not attached to the scapula, the forelegs were discovered to be hefty, with massive muscles, and three fingers were on the hand. The pelvis was linked to four sacral vertebrae that had short sacral ribs.

Large paired ovals with a pronounced curved ridge on the outer surface of the bony armour that covered the neck, shoulders, and forelimbs were keeled. The species’ small legs prevented it from running swiftly or across long distances, but the big muscles, on the other hand, may have made them more manoeuvrable than a rhinocerous. Panoplosaurus was unique among nodosaurids in that it lacked spikes on the sides of its neck, as evidenced by this specimen.

The dinosaur was a ground-dwelling creature that enjoyed a terrestrial environment, and with the dinosaur’s tiny legs and neck indicate that it ate low-height soft plants and flora and lived in locations where food was plentiful. All varieties of vegetation, including grasses, can be digested by it. They were not known to be particularly aggressive, but the dinosaur’s armour protected it from any prospective predators, and they may have even used the stiff tail to whip a blow.

Pantydraco

Nobu Tamura (http://spinops.blogspot.com), CC BY 3.0, via Wikimedia Commons

FURTHER READING AND STUDY 

• Paul (1988). Predatory Dinosaurs of the World
• Peter et al., (2007). Pantydraco n. gen. for Thecodontosaurus caducus YATES, 2003, a basal sauropodomorph dinosaur from the Upper Triassic or Lower Jurassic of South Wales
• Yates, (2003). A new species of the primitive dinosaur Thecodontosaurus and its implications for the systematics of early dinosaurs.

Pantydraco is pronounced “pant-ee-drak-oh,” and it is pronounced “Pant-y-ffynnon dragon.” The Pant-y-ffynnon quarry where the genus was discovered, is how it was given its name, which means “spring valley,” and “draco,” which means “dragon” or “draco-like creature” in Latin. 

It lived in Europe during the Triassic period, and it existed between 208.5 million and 201.3 million years ago while it lived in terrestrial settings. It is one of the very few dinosaurs found in the country of Wales. 

Thecodontosaurus caducus was Pantydraco’s previous name and only one Pantydraco species is recognised: P. caducus. The species name, caducus, means “fallen” in Latin, implying that it died after falling into a fissure fill (quarry). The Pant-y-ffynnon quarry in the Bonvilston province of South Wales, United Kingdom, was where its fossil remains were discovered.

A cranium, a partial jawbone, and cervical vertebrae, as well as an incomplete right pelvic bone and half forelimbs, were discovered in an underground limestone cave fissure in 1952. As the sacral neura are not fused together, the fossils are thought to belong to a young or non-adult dinosaur.

The Pantydraco dinosaur was a bipedal omnivorous that measured 3 metres in length and weighed 50 kilogrammes. The Pantydraco dinosaur had a medium build and stood about the same height as an adult human. The creature’s tail was long and tapered towards the end, with a large hip joint. It possessed a dragon-like head and a powerful jaw, and the dinosaur’s forelimbs were evolved to hold prey, while the creature’s hind limbs were adapted to maintain the creature’s body weight.

Pantydraco’s centre of mass is around the pelvic bone, indicating that it was bipedal. The forelimbs were significantly shorter than the hindlimbs. Three of the digits on the hands were movable, while the fourth was implanted.

Pantydraco used to move about by using its hind limbs, and as a result, we might presume they were reasonably quick runners. Their strong limbs, sturdy body, and well-developed fangs made it easy for them to catch their prey. Pantydraco reproduced through the depositing of eggs, which were amniotic in nature. They may have been quite territorial and very protective of their eggs and we can suppose that these dinosaurs either wandered in tiny groups, or lived alone. 

It used to wander the European continent’s rainforests, grasslands, and plains, foraging on a variety of plants and preying on other creatures. Pantydraco was an omnivore, which meant it ate both plants and animals. The species used to devour small insects and dinosaurs for food, and about 200 million years ago, Pantydraco dinosaurs became extinct.

Paralititan

Dmitry Bogdanov, CC BY 3.0, via Wikimedia Commons

FURTHER READING AND STUDY

• Smith and Lamanna (2001). A giant sauropod dinosaur from an Upper Cretaceous mangrove deposit in Egypt.
• Joshua et al., (‬2001). A Giant sauropod dinosaur from an Upper Cretaceous mangrove deposit in Egypt. ‬
• Carpenter (2005). ‬Biggest of the Big: ‬a Critical Re-evaluation of the Mega-sauropod Amphicoelias fragillimus

The word Paralititan means “tidal giant” and is pronounced “pa-ral-i-tie-tuhn.” The generic name “Stromer’s tidal titan” or “Stromer’s tidal giant” refers to the “paralic” tidal flats on which the species resided. During the Upper Cretaceous period, the paralititan dinosaur roamed the Earth between 99 and 94 million years ago. 

The huge titanosaurian herbivorous Sauropod Paralititan belonged to the genus Paralititan. The type species for this genus was P. stromeri. The name honors the paleontologist and geologist who discovered the dinosaur remains in 1911. The type species, Paralititan stromeri, was described and named in 2001.

Fossilized Paralititan was originally identified in Egypt’s Bahariya Formation’s Upper Cretaceous coastal deposits. The fossil was found in tidal flat sediments that also included fossil mangrove vegetation, with the specimen is a partial skeleton without the skull. Apart from two fused posterior sacral vertebrae, two anterior caudal vertebrae, both incomplete scapulae, two humeri, and a metacarpal, it is incomplete. The Paralititan type specimen was disarticulated within an oval of eight metres in length, with the numerous bones gathered, indicating that it had been scavenged by a carnivorous dinosaur. Since Romer’s 1935 publication, Paralititan is the first tetrapod to be discovered in the Bahariya Formation.

Despite the fact that the remains were well preserved, there were not many of them. Scientists have found that Paralititan was one of the largest dinosaurs to have ever lived, with an estimated weight of 59 tonnes, a length of 28 metres, and a height of 9 metres based on the available evidence. The humerus (upper ‘arm’ bone) is reported to have grown to a length of 169 cm. It has a long neck that allowed it to reach the topmost branches of trees swiftly., and a big gut that allowed it to digest vast volumes of plant matter. It walked on four legs and had a wide stance, and it has osteoderms (armoured plates in the back) that were designed to protect it from predators. Despite its size, the Paralititan most likely moved at a snail’s speed, however, its strides were fairly long, and it was estimated to move at a speed of roughly 8 kph. It was reconstructed using roughly 100 bone fragments from 16 distinct bones that were discovered. 

The Paralititan dinosaur was discovered predominantly in tidal areas and is the first dinosaur species to have lived among mangroves, according to research. This dinosaur’s scavenged skeleton was discovered in coastal deposits along the Tethys Sea’s beach. This herbivore dinosaur probably ate leaves, twigs, roots, and rudimentary fruits, vegetables, and seeds to stay alive. It was believed that it ingested roughly 326.6 kg of plant stuff every day and had a unique stomach to digest all of the plant matter. Due to its long neck, it could reach the tops of the highest trees and eat any form of leaf that was there as Paralititan food.  To defend itself against dangerous carnivores, the Paralititan generally had osteoderms and a wide-gauge stance to scare other dinosaur species.

Parasaurolophus

Leandra Walters, Phil Senter, James H. Robins, CC BY 2.5, via Wikimedia Commons

Parasaurolophus (pa-ra-saw-ROL-off-us) was a genus of hadrosaurid (duck-billed) dinosaur that lived towards the end of the Mesozoic, Campanian Age, during the Upper Cretaceous Period, around 76.5 – 73 million years ago, in the woodlands of North America. Parasaurolophus lived at the same time as Albertosaurus, Nanotyrannus, Lambeosaurus (another hadrosaur), Euoplocephalus, Kritosaurus and Pachyrhinosaurus.

Parasaurolophus measured 31 feet (9.5 metres) in length, 16 feet (5 metres) in height and weighed 2 – 3 tons. Like other hadrosaurs, Parasaurolophus was a bipedal and quadruped dinosaur and moved around and ran on its hind legs and would change to all 4 legs while foraging for food on the ground. It was quite a fast runner.

The most notable feature of the Parasaurolophus was its long curved crest on their heads which could measure 6 feet (1.8 metres) in length, it was larger than the rest of their skull.

Parksosaurus

Steveoc 86, CC BY-SA 3.0, via Wikimedia Commons

FURTHER READING AND STUDY

• ‬Sternberg ‬ (1937). Classification of Thescelosaurus, ‬with a description of a new species.
• Peter (1973). ‬Redescription of the skull and mandible of Parksosaurus from the Late Cretaceous with comments on the family Hypsilophodontidae
• Paul (2010). The Princeton Field Guide to Dinosaurs

Parksosaurus is pronounced, “PARKS-oh-SORE-us.” It was found in 1937 by palaeontologist William Parks and given the name Parksosaurus, which means “William Parks’ lizard.”  It existed some 66 million years ago in Alberta, Canada, in the Upper Cretaceous Horseshoe Canyon Formation of the Maastrichtian era. Parksosaurus is a genus of herbivorous neornithischian dinosaurs. Since its discovery, Parksosaurus has been classified as a hypsilophodont and the only type species for this genus is P. warreni. It’s one of the few non-hadrosaurid ornithopods known from the end of the Cretaceous period in North America, dating back roughly 70 million years.

This ornithopod‘s incomplete remains have been discovered in Alberta, Canada, and Montana, United States of America. Paleontologists discovered two separate fossils, each of which had a partially articulated skeleton and half head, 18 teeth, and bones in its ribs, thighs, legs, and toes.

A tiny dinosaur weighing 45 kilos and measuring 2.5 metres in length, they possessed powerful arms and long toes for trekking through muck and rivers. They had a horny, pointed beak, a small cranium, and a strong, short thigh, according to legend. The head was little and the neck was extremely lengthy, their ribs and hindlimbs were robust, and their cartilage was thin and ossified. They possessed a long tail and walked on two legs and the shoulder girdle was tough, with single teeth for slicing and cutting food. Due to similarities in body length, nutrition, and appearance, the specimen resembled other animals such the Thescelosaurus.  They benefited significantly from their strong thigh muscles, despite their diminutive size, as these dinosaurs had the ability to run at speeds of up to 30 miles per hour, its quickness and agility were essential for survival at the time. These hypsilophodonts reproduced sexually, laying roughly 2-3 eggs, just like any other mammal. In general, the Parksosaurus was not aggressive; but, when pursued by a predator, it would run quite rapidly.

This species was previously found in the Edmonton Formation and is now thought to be in the Horseshoe Canyon Formation. It was a herbivorous dinosaur that ate the foliage of low-level conifers, deciduous shrubs, and trees belonging to the angiosperms, a recently created group of flowering plants.  Despite the fact that predatory hunting was a factor in the population fall, they became extinct owing to harsh climate conditions on Earth.

Patagosaurus

Smokeybjb, CC BY-SA 3.0, via Wikimedia Commons

Patagosaurus (PAT-a-go-SAWR-us) was a huge dinosaur from the long-necked group Sauropoda who lived during the Callovian Age during the Middle Jurassic, 165 – 161 million years ago, in what is now Chubut, Argentina, South America. Other Argentinian dinosaurs living approximately at the same time were Piatnitzkysaurus, Condorraptor and Amygdalodon.

Patagosaurus measured 54 feet (16.5 metres) in length, 20 feet (6 metres) in height and weighed around 9,400kgs. Similar to other primitive sauropods, it was heavily built and similar to Cetiosaurus (Whale Lizard) in appearance but its hips and vertebrae were different. Patagosaurus had a very long neck which looked like a very thick trunk and a long, heavy tail. Its head was small and it had many cheek teeth for grinding plant material. It was quadrupedal and walked in all 4 thick legs.

Patagosaurus was a herbivore and ate plants. Its enemies were the theropod dinosaurs.

Pelecanimimus

Image source: El fosilmaníaco, CC BY-SA 4.0, via Wikimedia Commons

FURTHER READING AND STUDY

• Riley Black (2013). P is for Pelecanimimus
• Sanz et al., (1994). A unique multitoothed ornithomimosaur from the Lower Cretaceous of Spain.
• Paul (2010). The Princeton Field Guide to Dinosaurs

The word Pelecanimimus is pronounced “Pel-e-can-i-mime-us” and means “Pelican mimic.” The generic name comes from the Latin words pelecanus, which means “pelican,” and mimus, which means “mimic,” referring to the long snout and throat pouch. In 1994, it was given a name and a description, and it lived during the Cretaceous epoch and roamed Europe’s terrestrial areas 127 and 121 million years ago. 

Pelecanimimus is a basal (“basic”) ornithomimosaurian omnivore dinosaur genus and although Pelecanimimus was not closely related to lizards, it was a member of the Saurischia or “hip lizard” family. The sole type species is Polydon, and the particular name is derived from Greek “polys”, many, and “odous”, tooth, and refers to the theropod‘s huge number of teeth. Its remains have been discovered in  Spain (Aragon), and the only known specimen consists of the articulated front half of a skeleton, which includes the skull, lower jaws, all of the neck vertebrae and most of the back vertebrae, ribs, sternum, pectoral girdle, a complete right forelimb and most of the left forelimb, ribs, sternum, the pectoral girdle, and a complete right forelimb and most of the left forelimb. Soft-tissue remnants can be seen around the rear of the skull, around the neck, and around the front limbs.

Pelecanimimus was between 1.9 and 2.5 metres long, weighed 220 pounds, and stood 1 metre tall at the hips. Ostrich dinosaurs, Pelecanimimus. Almost all of these dinosaurs have been given names based on the birds they resemble. Pelecanimimus is additionally distinguished from subsequent species by the huge number of teeth still remaining in its mouth, which totals roughly two hundred and twenty. Its teeth were all unevenly spaced and had a tight “waist” between the crown and the base. Pelecanimimus also had a tiny crest on the back of its head, which was not found in other ornithomimosaurs. For further rigidity, the bones of the lower arm are packed tightly together, and the claws that emerge from the tips of the fingers are straight. It’s likely that the hands and claws were also used to catch prey or possibly feed it. Soft tissue impressions also demonstrate that Pelecanimimus’ skin was naked and scaley, indicating that he lacked a feather covering. Pelecanimimus may have behaved similarly to a modern-day crane, wading out in lakes or ponds with its claws and teeth catching fish and storing them in its skin flap. Pelecanimimus was also the first ornithomimosaur to have its hyoid apparatus intact (specialized tongue bones in the neck). 

Pelecanimimus lived and hunted in shallow waters and its teeth are supposed to have given him a cutting and ripping bite, but in subsequent forms, these teeth would be replaced with a keratinous beak that accomplished a similar task. Pelecanimimus was an omnivore dinosaur that ate both meat and vegetation, but it was also known to dive into the water to capture fish or other tiny aquatic animals like frogs. 

Pelorosaurus

Levi bernardo, CC BY-SA 3.0, via Wikimedia Commons

FURTHER READING AND STUDY

• Upchurch et al., (2015). The Anatomy and Phylogenetic Relationships of “Pelorosaurus“ becklesii (Neosauropoda, Macronaria) from the Early Cretaceous of England.
• Mantell, (1850). On the Pelorosaurus: an undescribed gigantic terrestrial reptile, whose remains are associated with those of the Iguanodon and other saurians in the strata of Tilgate Forest, in Sussex
• Holtz and Thomas (2012). Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages

The name Pelorosaurus means “monstrous lizard” and is pronounced, “pel-oh-ROW-sore-us.” The genus name comes from the Greek words “pelor,” which means “monster,” and “saurus,” which means “lizard.” Pelorosaurus existed from 150.8 million years ago to the Lower Cretaceous Epoch and occupied the terrestrial portions of Europe during the Cretaceous period.

Pelorosaurus is a titanosauriform herbivorous sauropod dinosaur genus. There is only one type species in this genus, P. conybeari. Pelorosaurus was named in 1850 and is believed to have been a brachiosaurid. Fossils have been discovered in Metropolitan France, England (United Kingdom). The sauropod dinosaur Pelorosaurus was described in 1852 from a related left humerus, ulna, radius, and skin impression from the Early Cretaceous (Berriasian-Valanginian) Hastings Beds Group near Hastings, East Sussex, southeast England. So far, three separate dinosaur specimens have been unearthed, including neck and back vertebrae, an arm bone, partial hind leg bones, partial hip bones, and a few other fragmented components. Skin impressions with hexagonal (six-sided) plates (9-26 mm across) have also been found.

The species is considerably larger, with an estimated length of over 24 m, a humerus (upper limb bone) length of around 4.5 ft, and a weight of around 14 thousand kilos. It was a colossal dinosaur with long necks, tails, small skulls, and four thick pillar-shaped legs. It was a plant-eating dinosaur with spatulate teeth. Previously, the genus was thought to be a cross between a Sauropoda and an Iguanodon. These dinosaurs were most likely precocial, meaning they were fully developed and mobile from the moment they were born. Intruders or guys from other herds must have been antagonistic to male dinosaurs.

This large monster lived in England and Portugal’s wetland and coastal habitats. Pelorosaurus most likely ate soft aquatic plants or used its teeth to nibble or scrape terrestrial plant fronds. Natural calamities may have caused the dinosaur to fall extinct 132 million years ago. 

Pentaceratops

Nobu Tamura (http://spinops.blogspot.com), CC BY-SA 3.0, via Wikimedia Commons

FURTHER READING AND STUDY

• Henry (1923). A new genus and species of Ceratopsia from New Mexico, Pentaceratops sternbergii
• Rowe (1981). The occurrence of Pentaceratops with a description of its frill
• Lehman (1998). A gigantic skull and skeleton of the horned dinosaur Pentaceratops sternbergi

The name Pentaceratops means “five-horned face” and is pronounced, “pent-ah-ker-ah-tops.” The generic name is derived from the Greek “penta” meaning five, “keras” meaning horn, and “ops” meaning face, in reference to its two long epijugal bones, spikes that stick out side wards from behind its eyes. It lived throughout the Cretaceous period and inhabited in the terrestrial areas of North America from 83.5 million years ago, until the Maastrichtian Age.

The herbivorous ceratopsid dinosaur Pentaceratops is a genus of herbivorous ceratopsid dinosaurs. When the type species, Pentaceratops sternbergii, was described in 1923, the genus was given its name. The specific name sternbergii was given to the species in honor of its discoverer. 

This dinosaur’s remains were discovered in the Isla Sorna Formation and later in the Dinosaur Park Formation and Kirtland Formation, fossils have also been discovered in eastern Asia. The first Pentaceratops fossil, a partial skull, was discovered in 1891 in Wyoming, while  a cranium and a rump were discovered in a stratum of the Kirtland Formation near the Kimbetoh Wash in 1921. A pair of brow horns, a portion of skull frill, a right squamosal, half skeletons with skulls, a skeleton minus the skull, and fragmented skulls are among the 16 specimens recovered thus far. Apart from these, a juvenile Pentaceratops specimen has also been unearthed.

Pentaceratops was roughly 6 meters long and weighed about 5 tons. It has a short nose horn, two long brow horns, and lengthy jugal bone horns. It has a lengthy frill on its cranium with triangular hornlets on the edge, and one fascinating fact about them is that they have a rhinoceros-like appearance. It was squat, walked on four legs, and possessed a beak and a large number of cheek teeth. From where the ligaments ran to the front, the vertebrae had a fairly lengthy spine. The skull measured approximately 2.3 meters in length, which is unusually large for a dinosaur. They have a horn on their snout that is directed upwards and backward, and the horns above both eyes were curled forward at the same time. The frill on their heads was tilted forward, and the front feet were narrower than the back feet, which were wider. There were no eggs laid by the Pentaceratops, but instead, female members of this species gave birth to new offspring. Mothers were the primary caregivers for young Pentaceratops. According to paleontologists, the five horns or beaks they possessed were utilized to protect them from predators, and their weight also helped them gain an advantage in combat.

As a terrestrial animal, this dinosaur liked grasslands, marsh areas, wetlands, scrublands, woods, long grasses, or other locations with enough water and plant material to feed, as they were herbivores. It ate mostly low-lying foliage and plants, plucking and slicing ferns and cycads with its long, flat teeth. This animal went extinct 65-64 million years ago as a result of an asteroid strike.

Piatnitzkysaurus

Paleocolour, CC BY-SA 4.0, via Wikimedia Commons

Piatnitzkysaurus (pye-at-nits-key-sore-us) is the name given to a genus of megalosaurid dinosaur who lived in the Callovian stage during the Upper Jurassic Period, around 166 – 164 million years ago in Chubut, Argentina, South America.

Piatnitzkysaurus measured 14 feet (4.3 metres) in length, 8 feet (2.5 metres) in height and weighed around 275 kilograms. Piatnitzkysaurus was a lightly built medium-sized bipedal dinosaur with short, clawed arms. It had a long stiff tail which it used for counter-balance, ridges on its snout and a distinguished crest on its head. Its body was heavily built and it had a large head on a short neck. Its hind legs were powerful and were equipped with sharp clawed toes on the feet. This dangerous dinosaur had many razor sharp teeth with which it would slice the flesh of its unfortunate prey.

Piatnitzkysaurus was a ferocious carnivore and is thought to have terrorized the plant eaters of that time.

Pinacosaurus

Audrey.m.horn, CC BY-SA 4.0, via Wikimedia Commons

FURTHER READING AND STUDY 

• Michael et al., (2011). Juvenile specimens of Pinacosaurus grangeri Gilmore, 1933 from the Late Cretaceous of China
• Currie et al., (2011). Hands, Feet, and Behaviour in Pinacosaurus
• Hill et al., (2003). A New Specimen of Pinacosaurus grangeri from the Late Cretaceous of Mongolia: Ontogeny and Phylogeny of Ankylosaurs

Pinacosaurus is a lizard that is pronounced “pin-ak-oh-sore-us” and means “plank lizard.” The generic name comes from the Greek word “pinax,” which means “plank,” and refers to the tiny rectangular scutes that cover the skull. It thrived in Asia mainly Mongolia and China throughout the Cretaceous period and existed in the terrestrial habitat from 145 million to 66 million years ago.

Its fossils have been discovered in Inner Mongolia and China, and Pinacosaurus is a herbivorous ankylosaurid thyreophoran dinosaur genus. Pinacosaurus grangeri was identified as the type species and named in 1933 by Granger, a palaeontologist who joined the 1923 trip. The second possible legitimate species, Pinacosaurus mephistocephalus, was identified in 1999 and differs from the type species in characteristics of the skull armour.  Pinacosaurus may have wandered in herds, as evidenced by the discovery of over 35 fragmentary remains, several of which were found in vast bonebeds. The first remnants of the genus were discovered in 1923 in the Campanian Djadokhta Formation which consisted of a partially crushed head, a full skull, dermal bones, first two neck vertebrae, and lower jaws with a total length of 196.8 inches. Other fossils discovered include a partially crushed skull, lower jaws, the first two neck vertebrae, and dermal bones, a virtually full skeleton, a postcranial skeleton, the handle of a tail club, a cranium, and extensive bonebeds of juvenile animals.

Pinacosaurus was a medium-sized ankylosaurid thyreophoran dinosaur with a total body length of 5 meters, a height of 17.7 inches, and a weight of 2,000 kilograms. It had a strong torso, armored shields on its back, and a club-shaped tail, all of which were supported by four short, stout legs. It featured two pairs of egg-shaped openings in the skull where the nostrils would ordinarily be positioned. The term comes from the fact that the skull was protected by bone tiles and each nostril was created as a huge depression with three to five smaller holes piercing it, the purpose of which is unknown. Low-growing plants were bitten off by a smooth beak, which was subsequently diced by rows of small teeth and ingested to be processed by the huge hind gut. An armor of keeled osteoderms protected the neck, back, and tail. The dinosaur might potentially have used a tail club to aggressively defend itself.

Pinacosaurus is thought to have been herbivorous, feeding on the leaves of the dry area plant because its teeth were so little. The muscular tongue of P. grangeri was extremely important. Pinacosaurus went extinct around 86 million years ago, during the late Cretaceous period.

Plateosaurus

DataBase Center for Life Science (DBCLS), CC BY 4.0, via Wikimedia Commons

Plateosaurus (plat-ee-oh-SORE-us) was the largest dinosaur known to have existed during the Triassic Period of the Mesozoic Era 214 – 204 million years ago in desert-like land in Europe. Plateosaurus was a prosauropod and a plateosaurid, heavy, thick-limbed herbivores that include Massospondylus, Mussaurus and Plateosaurus. Among its contemporaries in Triassic Europe were Saltopus and Proganochelys, the earliest known turtle.

Plateosaurus measured up to 33 feet (10 metres) in length and weighed around 4 tons. It had a bulky body with a pear shaped thrunk and a long, flexible neck composed of 10 cervical vertebrae. The skull of Plateosaurus was deeper than that of a Coelophysis, although still small and narrow compared to the size of its body. It had a long snout and sharp, serrated teeth that were leaf-shaped crowns suitable for crushing plant material and its eyes were directed to the sides, rather than the front, providing all-round vision to watch for predators. Plateosaurus had a flexible tail composed of at least 40 caudal vertebrae.

Podokesaurus

FunkMonk (Michael B. H.), CC BY-SA 3.0, via Wikimedia Commons

FURTHER READING AND STUDY

• Talbot (1911). Podokesaurus holyokensis, a new dinosaur from the Triassic of the Connecticut Valley
• Paul (2016). “Theropods”. The Princeton Field Guide to Dinosaurs
• Paul (1988). Predatory Dinosaurs of the World.

“Po-doh-kee-sore-us” is how Podokesaurus (swift-footed lizard) is pronounced. The generic name is derived from the Ancient Greek terms “podks” and “saura,” which mean “quick (or fleet)-footed,” an adjective usually applied to the Greek hero Achilles, and “saura,” which means “lizard.”

A Podokesaurus can be traced back to the Mesozoic era’s early Jurassic Period. Podokesaurus roamed the the eastern United States, and was one of the first dinosaurs to live in the United States. Podokesaurus is a genus of small carnivorous dinosaurs belonging to the coelophysoid family. P. holyokensis is the only species that belong to this genus. Holyoke is the name of the town.  In full, the name can be translated as “swift-footed lizard of Holyoke”.

In 1910, at Mount Holyoke, Massachusetts, the first fossil of this psecies was unearthed. Much of the body, limbs, and tail were preserved in the fragmented specimen. 5 cervical, 11 dorsal, and 24 caudal vertebrae, a fragment of the left scapula, right coracoid, a partial left humerus, phalanx bones of 3 fingers, including 2 unguals, ribs, the pubis and ischium, the femora, the left tibia, a fragment of the right astragalus, and articulated metatarsals of the left foot were discovered from Holyoke, Massachusetts. 

It was a small bipedal dinosaur with an estimated weight of 4 kg and a length of 1 m and a height of 0.3 m. Due to it having hollow bones, Podokesaurus holyokensis was thought to be a light-weighted Theropoda species. They possessed long necks and recurved, sharp teeth. Aside from that, the vertebrae were slender and hollow, with a little concavity at each end of some of them. The vertebrae in the neck were large, while the vertebrae in the tail were long and slender. The femur and humerus were both narrow and weak. Both the front and back ends of the pubis grew in length and slenderness. This Theropoda was a fast-footed predator with strong forelimbs and gripping hands. A Podokesaurus reproduced through oviparity, and they frequently made defensive gestures to safeguard their territory or eggs.

They liked tundra vegetation with highly vegetated lakes and forests as neighbours. It was most likely a carnivorous dinosaur that ate tiny herbivores.  The Podokesaurus went extinct around 65 million years ago, near the end of the Cretaceous Period of the Mesozoic era.

Poekilopleuron

PaleoEquii, CC BY-SA 4.0, via Wikimedia Commons

FURTHER READING AND STUDY

• Allain and Daniel (2002). Poekilopleuron bucklandii, the theropod dinosaur from the Middle Jurassic (Bathonian) of Normandy
• Hulke (1879). Note on Poekilopleuron bucklandi of Eudes Deslongchamps (père), identifying it with Megalosaurus bucklandi.
• Seeley (1887). On Aristosuchus pusillus Owen, being further notes on the fossils described by Sir R. Owen as Poikilopleuron pusillus Owen

Poekilopleuron, which means “variable ribs,” is pronounced, “peek-i-loh-ploor-on.” The generic name comes from the Greek words “poikilos,” which means “variable,” and “pleuron,” which means “rib,” referring to the three varieties of ribs found. Around 168-166 million years ago, Poekilopleuron lived in the Bathonian stage of the middle Jurassic epoch. The specimen was discovered in France, implying that they travelled the European continent. 

Poekilopleuron is a genus of predatory tetanuran dinosaurs. P. bucklandii is the type species, and the specific name honors William Buckland. Based on holotype material that has since been lost, the genus was first named and described in a report published in 1836. Poekilopleuron was named after a fragmentary skeleton discovered in a stratum of the Calcaire de Caen Formation in La Maladrerie in Normandy, France, in July 1835. This skeleton was destroyed during World War II’s Battle of Caen in 1944, and the taxon subsequently had to be examined using cast reproductions. Caudal vertebrae, cervical ribs, ribs, belly ribs (gastralia), a forelimb, and a hindlimb were among the remnants. The fossil of Poekilopleuron showed a rare set of gastralia: fourteen pairs of belly ribs supported the body of the animal.

Poekilopleuron was a lizard-like creature that grew to be rather large. It measured 9.1 meters in length and weighed 907.2 kilograms. Poekilopleuron’s forelimbs were its most distinguishing trait. Their size, roughly 2 feet long, indicated that this theropod had a more primitive construction. The arms of Poekilopleuron were long and, by extension, powerful, the forearms were markedly short and robust. The absence of the olecranon process on the ulna is a distinguishing trait, and when compared to a featherless raptor, it had a comparable physical appearance. They were therapoda dinosaurs with hollow bones to reduce body weight and increase speed, as well as a very long tail. Their forelimbs were not properly formed and they had small hands, which were not very useful, thus the formation was pretty feeble. They needed powerful and keen teeth to conquer their prey because they were carnivores. They were running on two legs and the quantity of information gleaned from the shattered holotypes indicates that they were fearsome predators of good size. As they were carnivorous, they were naturally aggressive, they were a nice length and had all of the necessary equipment to be a top predator. They were one of the most terrifying dinosaurs ever but also relatively unknown compared to some of their relatives.

They were predatory terrestrial creatures that hunted for prey on land, and they resided in Europe and travelled throughout France and the surrounding areas. They were carnivorous dinosaurs who ate other herbivorous dinosaurs, and lived roughly 168-166 million years ago, during the middle Jurassic period. 

Polacanthus

FunkMonk (Michael B. H.), hip armour by Franz Nopcsa von Felső-Szilvás, CC BY-SA 3.0, via Wikimedia Commons

FURTHER READING AND STUDY

Xabier et al., (2007). New remains of the ankylosaurian dinosaur Polacanthus from the Lower Cretaceous of Soria, Spain. 

Blows (1987). The armoured dinosaur Polacanthus foxi, from the Lower Cretaceous of the Isle of Wight

Blows (1996). A new species of Polacanthus (Ornithischia; Ankylosauria) from the Lower Cretaceous of Sussex, England.

Polacanthus, which means’ many spines,’ is pronounced: “pol-a-KAN-thus.” This term comes from the Ancient Greek words “polys” (many) and “akantha” (thorn or prickly). It lived in Europe and roamed the terrestrial environments from the Lower Cretaceous Epoch to 99.6 million years ago. Polacanthus was a plant-eating ankylosaurian herbivorous dinosaur with armored spikes. Several species have been named in the genus Polacanthus, but only the original species Polacanthus foxii is now considered legitimate, and the specific name honors Fox. 

Its fossils have been discovered in Castile and León, England, and Castellon, among other places. The first specimen was discovered in a bed of blue clay, which appears near the centre of the cliff, a small distance east of Barnes Chine in 1881. The holotype was discovered in a Barremian stratum of the Upper Wessex Formation including the head, neck, dorsal vertebrae, a sacral rod with five dorsosacrals, the sacrum, most of the pelvis, most of the left hindleg, the right thighbone, twenty-two tail vertebrae, ribs, chevrons, ossified tendons, a pelvic shield, twenty-two spikes, and numerous ossicles make up this incomplete skeleton. Polacanthus has since been assigned to nearly 14 more specimens from the Isle of Wight and the United Kingdom. These usually consist of single bones or armour pieces.

These dinosaurs were 5 meters (16 feet) long, 2 meters (7 feet) tall, and weighed 2 tons. The armored dinosaur Polacanthus walked on four legs with rows of spikes across the length of its back and a large pony plate over its hips to protect itself from predators. They also featured a row of spines along their tail, but they were one of the first armored dinosaurs to evolve without a club at the end. It had a well-developed brain and was likely quite attentive and mobile as an ankylosaur. The hindlimbs of an ankylosaur were quite lengthy. The bottom of the neural tube is profoundly split by a channel with a V-shaped transverse profile, and the tail spikes have a triangular base and a narrow tip, which are autapomorphies. They had a ‘floating’ shield on their backs that wasn’t attached to any of their bones. Polacanthus is a shy species that prefers to dwell alone, in pairs, or in groups of three in a small enclosure with only a few other species. If the enclosure becomes too crowded, they can easily become stressed.

They dwelt mostly in what is now known as the Isle of Wight, an area of modern-day England. Polacanthus were herbivores who foraged on the ground for sustenance. Conifers were the mainstay of the Polacanthus diet.  After an asteroid struck the Earth, the dinosaur Polacanthus age came to an end with a mass extinction.

Prenocephale

AntoninJury, CC BY-SA 4.0, via Wikimedia Commons

FURTHER READING AND STUDY

Maryanska and Osmolska (1974). Pachycephalosauria, a new suborder of ornithischian dinosaurs

Palmer, ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals.

Evans et al., (2013). The oldest North American pachycephalosaurid and the hidden diversity of small-bodied ornithischian dinosaurs

Prenocephale means “sloping head” and is pronounced: “preen-oh-keff-ah-lee.” Prenocephale was a tiny herbivorous pachycephalosaurid dinosaur genus and belongs to the Ornithischia (“bird-hipped”) group. This suggests that, while Prenocephale was not closely related to birds, its pelvic bones were comparable in morphology. P. prenes is the type species, and Homalocephale is the genus’s synonym. The animal was named and described in 1974.

It lived in Asia during the Cretaceous period, and roamed the Mongolian deserts, as well as potentially North America, from 83.6 million years ago through the Maastrichtian Age.  Its fossils have been discovered in Alberta, New Mexico, and Mnögovi (Mongolia), among other places. Only a few Prenocephale fossil bones have been discovered, including the sloped head. The remains of this dinosaur were discovered and gathered during the Joint Polish-Mongolian Expeditions to the famed Asian desert, the Gobi Desert, where palaeontologists discovered 11 different specimens.

Prenocephale measured about 2.4 metres in length and weighed around 130 kg. The Prenocephale skull was slanted and rounded rather than flat, and a row of numerous bumps and little bony spikes adorned this dome-head. The Prenocephale is commonly represented as having a sturdy body, a short and thick neck, tall hindlimbs, and short forelimbs in reconstructions of this specimen. The nose of a Prenocephale is significantly narrower, and Prenocephale may have had an excellent vision due to its wide eye sockets. The head was thick, allowing it to fossilize successfully, although the rest of its body may not have, and It had basic teeth. It looked a lot like the Homalocephale, which could be a younger version of the Prenocephale.

This species was thought to live in high-altitude forestlands or deserts. It was a plant-eating herbivore that most likely ate soft leaves or fruits. If it could capture insects, it presumably ate them as well.  It was one among the dinosaurs that perished 65 million years ago during the Cretaceous-Tertiary extinction.

Probactrosaurus

Deibvort, CC BY-SA 3.0, via Wikimedia Commons

Probactrosaurus (proh-bak-troh-sore-us) was an early duck-billed hadrosauroid iguanodont. It lived in the Aptian to Albian Age, during the Early Cretaceous Period 130 – 125 million years ago in Mawortuh, Alashan Desert, inner Mongolia, China.

Probactrosaurus measured 17 – 18 feet (5 – 5.5 metres) in length and weighed 1,000 kilograms. It had a narrow snout, an elongated lower jaw and double rows of flattened cheek teeth that were suitable for cropping soft vegetation. The duckbills had as many as five rows of teeth in the jaw, one beneath the other. Broken teeth were quickly replaced. Its tail was long, heavy and stiff and held this way by tendons. The hind feet had one toe that faced the opposite direction of its other toes, allowing it to grasp objects.

Probactrosaurus was a herbivorous dinosaur and would have ate a huge amount of plant material to sustain itself. These dinosaurs would eat on all 4 legs (quadrupedal) but when moving fast, would raise up on the hind legs (bipedal) using their tails to balance.

Proceratosaurus

Image source: Nobu Tamura, CC BY-SA 3.0, via Wikimedia Commons

FURTHER READING AND STUDY

Rauhut et al., (2010). Cranial osteology and phylogenetic position of the theropod dinosaur Proceratosaurus bradleyi from the Middle Jurassic of England

Woodward (1910). On a skull of Megalosaurus from the Great Oolite of Minchinhampton 

Huene (1926). On several known and unknown reptiles of the order Saurischia from England and France

The name Proceratosaurus means ‘before Ceratosaurus.’ It is pronounced, “proh-ker-at-oh-sore-us.” Due to the partially surviving piece of Proceratosaurus’ crest superficially resembles the short crest of Ceratosaurus, it was previously assumed to be an ancestor of Ceratosaurus. It was given its name in 1926. P. bradleyi is the type species of the genus Proceratosaurus, which is a small carnivorous theropod dinosaur. It existed from 86.3 million years ago to the Maastrichtian Age and occupied the terrestrial lands of Asia and North America during the Cretaceous period. 

During the Middle Jurassic, Proceratosaurus thrived in what is now England, Europe, around 168-166 million years ago. The single known specimen, a 30cm-long head, was discovered in Gloucestershire, England, in the early 1900s and named Megalosaurus in 1910, however, in 2009 it was reclassified as a tyrannosauroid. A fissure in the rock had eroded the upper section of the head, which was partially filled with calcite. 

The Proceratosaurus grew to a height of 2.13 m, a length of 3 m, and a weight of 150 kg. Because Proceratosaurus is a carnivorous dinosaur, it is thought to be a terrible creature. The Proceratosaurus brain had a very pronounced crest above the nasal cavity in the skull fossil, and it was a fascinating historical animal. The teeth of the Proceratosaurus were razor-sharp and extremely efficient, it could readily bring down large herbivores with its muscular jaws lined with long sharp teeth.

The crest of the Proceratosaurus skull was roundish and quite robust and it has two feet and a very strong and conspicuous nasal bone. They had internal air holes in their skulls, as well as the D-shaped front teeth that all tyrannosaurs have. It had a nasal crest, which could have served as a display organ as well as reducing bending forces on the skull during biting. It may have had 330 bones in its body, including a robust cranium and a nasal bone. Among its distant relatives’ ceratopsians, Proceratosaurus from the Jurassic period was just as aggressive and combat-ready. These theropods have thick shells that would have protected them from most predators. 

They were frequently located near rivers, where they could look for and discover plenty of freshwater fish ready to be caught, as prey items that would be simple pickings if they came across one while hunting. Proceratosaurus was a carnivorous theropod dinosaur that hunted hadrosaurs and other tame herbivores, as well as battled with other tiny predators.

Procompsognathus

FunkMonk (Michael B. H.), CC BY-SA 3.0, via Wikimedia Commons

FURTHER READING AND STUDY

• Paul (1988). Predatory Dinosaurs of the World
• Strauss (2020). Profile of the Procompsognathus
• Chatterjee (1993). Procompsognathus from the Triassic of Germany is not a crocodylomorph

Procompsognathus, which means “before Compsognathus,” is pronounced, “pro-comp-sog-nay-thus.” The name Procompsognathus, which derives from the name of another dinosaur called Compsognathus, means “before exquisite jaw” and it was named in 1913.  Approximately 222-219 million years ago, during the Late Triassic Period, the Procompsognathus inhabited the world, and it lived in Europe’s terrestrial areas and marshes. The sole type species for this genus is P. triassicus. Triassic, the geologic era to which this dinosaur belongs, is referenced specifically by the name triassicus.

Its fossils have been discovered in locations like Grand Est (France), in the middle Stubensandstein section of the Lowenstein Formation in 1909, the remnants of the Procompsognathus skeleton that were badly preserved were discovered. The specimen was made up of the fragmented remnants of a skull and jaw bone, as well as the postcranial skeleton, which included the ribs, shoulder girdle, hip bone, pubic bones, one forelimb, and both hindlimbs. Two other specimens were found in 1921, one of which was a left hand that was by itself and the other of which was a half cranium and lower jaw. Compared to the preceding specimen, these belonged to a larger person.

Theropod Procompsognathus measured only 3 feet in length. They could reach lengths of around 3.8 feet, hip heights of 10 inches, and weights of 2.2 pounds. It had short forelimbs and larger rear limbs. The tibia is longer than the femur by around 20%, and the Procompsognathus was a swift runner because of this characteristic, which evolved from dinosaurs’ cursorial habits. The animal has lengthy hands with strong claws, and the nose was medium in size, elongated, and had a lot of tiny teeth. The tail was less flexible and stiff, and they were bipedal carnivorous dinosaurs with a very light physique that lived on the ground. These creatures were hostile, but only toward their own clan members who were roughly their own size. There were fewer signs of hostility because almost all of the dinosaurs that coexisted with them were larger than them. It was the size of a chicken, but the recent discovery was about the size of a turkey. It may have consumed insects, lizards, and other tiny animals because it resided in a somewhat dry, inland area. 

They may have become extinct around 200 million years ago because they were one of the earliest dinosaurs and were so small. 

Prosaurolophus

I, Steveoc 86, CC BY 3.0, via Wikimedia Commons

FURTHER STUDY AND READING

• Brown (1916). A new crested trachodont dinosaur, Prosaurolophus maximus.
• McGarrity et al., (2013). Cranial anatomy and variation in Prosaurolophus maximus
• Prieto-Marquez (2008). Phylogeny and Historical Biogeography of Hadrosaurid Dinosaurs

Prosaurolophus, which means “before lizard crest” or “before Saurolophus,” is pronounced, “proh-sore-oh-lof-us.” Prosaurolophus, a brand-new genus, was described in 1916, and the genus Saurolophus,  possessed a comparable but longer and more spike-like head crest. It colonized North America during the Cretaceous period. It roamed the terrestrial regions between 85.8 million years ago through the Maastrichtian Age. 

A species of Hadrosaurid dinosaur with a duck-bill, the Prosaurolophus was a herbivorous dinosaur. The type species is P. maximus, which was identified in 1916; P. blackfeetensis, which was identified in 1992, is the second species. The size of the crest and the proportions of the skull were the key differences between the two species. Prosaurolophus’ existence is unknown despite the fact that it is known from the skeletons of 24-29 individuals, some of which are articulated (the bones were linked as they would have been in life), belonging to two species. Its fossils have been discovered in late Campanian Upper Cretaceous Dinosaur Park Formation in Alberta, Saskatchewan, and in the roughly contemporaneous Two Medicine Formation in Montana and the, of which date to approximately 75.5-74.0 million years ago.

These were diminutive Hadrosaurids, measuring around 7.9 meters in length, 4.3 meters in height, and weighing about 4,500 kilograms. The Prosaurolophus had a huge, flattened head with a mouth that was shaped like a duck, it also had a triangle-shaped crest around its eyes and a tiny, robust nose. Since their crest is known to have formed in an isometric structure, it is assumed that these dinosaurs had soft tissue growths like inflating nasal sacs. There have been claims that Prosaurolophus had webbed feet, but new information suggests that they may have also had padded feet. It was long and bulky, with huge ribs, and had a thick, stiff tail, which in contrast to the P. blackfeetensis species’ enormous crest and skull, the P. maximus species has a smaller skull. When the latter reached maturity, the crest also developed more noticeably and grew closer to the eyes. It is believed that the crest’s concave shape and scooped sides served as some kind of eye protection. Their teeth were constantly being replaced and only a small number of the hundreds of teeth were ever used. According to studies, they roamed in herds and may have utilized the Prosaurolophus sound or vocalizations to coordinate their movements. According to studies, they chose nesting locations in both upland and lowland areas, based on the availability of food, competition, and general environmental circumstances.

These dinosaurs were found along the shores of lakes, ponds, and rivers. The Prosaurolophus was built with a mouth resembling a duck’s bill to consume dense plants. They could perform continuous grinding motions based on their skull, and evidence shows that these dinosaurs may have been grazers. These dinosaurs may have consumed mushrooms and rotting tree bark, according to recently discovered fossilized feces. However, its beak appears to have been shaped to cut leaves and branches from trees around 13 feet above the ground. Prosaurolophus is thought to have died out between 75 and 74 million years ago.

Protarchaeopteryx

Clara Takahashi, CC BY-SA 4.0, via Wikimedia Commons

FURTHER READING AND STUDY

• Ji and Ji (1997). Protarchaeopterygid bird (Protarchaeopteryx gen. nov.), fossil remains of archaeopterygids from China
• Paul (2010). The Princeton Field Guide to Dinosaurs
• Qiang et al., (1998). Two feathered dinosaurs from northeastern China

Protarchaeopteryx, which means “before Archaeopteryx,” is pronounced “pro-tark-ee-op-ter-iks.” Since it resembled non-avian theropods a little more than Archaeopteryx, this species is regarded as being more primitive, and because of this, it was known as the “first ancient wing” or Archaeopteryx earlier. An omnivorous theropod with feathers the size of a turkey belongs to the genus Protarchaeopteryx. The type species for this genus is Protarchaeopteryx robusta. Protarchaeopteryx flourished in the Early Cretaceous, roughly 122-135 million years ago, and it lived in Asia’s terrestrial regions through the Aptian Age. 

In 1996, in China’s Liaoning Province (in northeastern China), a fossilised Protarchaeopteryx was discovered in the sediment of an old lake bed. A fragmentary skeleton with leg bones makes up the holotype, or only existent specimen, of a Protarchaeopteryx dinosaur. According to the evidence, they had long, slender arms, sharp, curved claws, a tail that was relatively short, and well-developed feathers. Similar to a modern bird, the bones were hollow, and the fossil’s host rock, which has been kept well, gave conclusive proof that the prehistoric animals had feathers, as well as several exquisite characteristics.

A Protarchaeopteryx could reach a length of 1 m, a height of 7 m, and a weight of about 4 kg. This species’ fossilized remnants are evidence that certain dinosaurs had feathers, however, this dinosaur’s feathers are entirely different from those of contemporary birds that fly. Since Protarchaeopteryx’s bone structure couldn’t sustain flapping flight, this dinosaur lacked flight feathers. According to certain paleontologists, these feathers served two functions: they kept the dinosaur warm and may have attracted partners during the breeding season. Protarchaeopteryx possessed long legs, three-toed feet that resembled ostriches’ feet, a small, toothless cranium supported by a thin, extremely flexible neck, and a short tail with well-developed feathers. The hands or arms have three long, slender fingers with pointed, curved claws. It had a wishbone that was 1 m long and hollow, like the bones of a bird. They were among the most intelligent dinosaurs and were small, swift runners. Some ideas contend that they were lonely dinosaurs that looked like birds, while others contend that they lived in small groups like some modern birds.

This species could be found in forests, mountainous areas, along rivers, and close to floodplains. Although some argue that they were herbivores, these winged dinosaurs were mostly omnivores. It has been hypothesized that this creature may have lived an arboreal lifestyle, jumping from tree limbs and using its forelimbs as a kind of parachute. Nearly 65 million years ago, during the K-T mass extinction, these dinosaurs perished.

Protoceratops

Emily Willoughby (e.deinonychus@gmail.com, http://emilywilloughby.com), CC BY-SA 3.0, via Wikimedia Commons

Protoceratops is a genus of ceratopsian dinosaur that lived in the Campanian stage during the Upper Cretaceous period, 74 – 70 million years ago, in what is now Mongolia, China. It was a member of the Protoceratopsidae, a group of early horned dinosaurs. Protoceratops was the first named protoceratopsian and therefore gives its name to the family Protoceratopsidae. Other ceratopsian dinosaurs include Triceratops and Styracosaurus.

Protoceratops was a small dinosaur and measured 6 feet (1.8 metres) in length, 3 feet (0.9 metres) in height to the top of its shoulders and weighed 200 kilograms (900 pounds). They were about the size of a modern sheep. Around its neck was a large frill which may have been used for protection of the neck or as a means of attracting mates and impressing other members of the species. The frill contained large holes and varied in size and shape depending on individual. Some had short frills while others had frills the size of their skull. Protoceratops walked relatively slowly on 4 short, thick legs and a bulky body.

Protohadros

Image source

FURTHER READING AND STUDY

• ‬Head (‬1996). A primitive hadrosaur ‬from the Cenomanian of Texas and its implications for hadrosaurian phylogenetic and biogeographic histories.
• Head (‬1998). A new species of basal hadrosaurid ‬from the Cenomanian of Texas.
• Yuong (1997). Bird and dinosaur footprints in the Woodbine Formation (Cenomanian), Texas

Protohadros, which means “first hadrosaur,” is pronounced, “proh-toh-had-ros.” The word “protos” means “first” and “hadros” means thick in Greek, and it refers to the fact that Head thought this particular species to be the first known hadrosaur.  It colonized North America during the Cretaceous period, and inhabited the terrestrial regions from the Cenomanian Age to 93.5 million years ago. 

The type species of the herbivorous ornithischian dinosaur genus Protohadros is Protohadros byrdi. The specific name Protohadros byrdi, which honors Byrd, was given to the type species in 1998. Protohadros postcranial remnants and a partial skull have both been discovered in 1994 at Flower Mound in North Central Texas, USA. A few ribs, a hand ungul, and foot bones were also discovered.

Protohadros was a medium-sized dinosaur that measured around 27.6 in height, 275.6 in length, and 1814.3 kg in weight. The palaeontologists estimate the size of their cranium to be about 27.6 inches. These species’ enormous lower jaws made it easier for them to grind and crush plants and branches and they were able to graze more easily thanks to their long, projecting nose at the front. They had a system of cranial joints in the back of their skulls, which aided in the grinding and chewing of their food. These herbivorous dinosaurs could only move or run on their hind legs since their rear legs were longer than their front legs.

A plant-eating dinosaur, protohadros could rear up on just its two hind legs to feed on high foliage or potentially to flee from predators. Protohadros would have primarily moved around on four legs, they had cheek teeth in the sides of their mouths and horny, toothless beaks.

They were able to talk and converse, with many paleontologists believing that the calls of these animals resembled cracking noises.

They possessed rough skin, hoof-like nails on their feet, and stiff tails that were probably employed for balance. They held their head and tail horizontally as they ran on two legs. This was one of the dinosaurs in between iguanodonts and hadrosaurs.

Psittacosaurus

Nobu Tamura (http://spinops.blogspot.com), CC BY 3.0, via Wikimedia Commons

FURTHER READING AND STUDY

• Sereno (1990). New data on parrot-beaked dinosaurs (Psittacosaurus)
• Sereno et al., (2007). New psittacosaurid highlights skull enlargement in horned dinosaurs
• Sereno (2010). Taxonomy, cranial morphology, and relationships of parrot-beaked dinosaurs

Psittacosaurus, which means “parrot lizard,” is pronounced, “SIT-ak-oh-sore-us.” The generic name Psittacosaurus was given in 1923 and is made up of the Greek terms “psittakos” for parrot and “sauros” for a lizard, as suggested by the animal’s ostensibly parrot-like beaks and their reptilian origin. Psittacosaurus is a genus that lived between 123.2 and 100 million years ago in what is now Asia during the Early Cretaceous period. The genus may have existed for more than 30 million years.

A genus of prehistoric ceratopsian herbivorous dinosaurs called Psittacosaurus existed. It stands out as the non-avian dinosaur genus with the greatest diversity of species. There are up to 12 species in this genus, with Psittacosaurus mongoliensis being the type species.

Mongolia, China, and Russia are a few locations where its fossils have been discovered. The Gobi Desert in Mongolia is home to the dinosaur’s first fossils that were found, which include a nearly complete skull and a postcranial skeleton with missing leg segments. Nearly 400 specimens have been collected from diverse sites, including full Psittacosaurus skeletons of individuals (adult and juvenile forms) together with their age classes. These specimens have offered remarkable information about the morphological characteristics of these dinosaurs. In 1923, a specimen of the holotype was found in Mongolia. Its relevance as an index fossil for Early Cretaceous deposits of central Asia is due to the dinosaur’s prevalence in the fossil record.

An adult’s body measured 2 meters, they were around 1.2 meters tall, weighed close to 20 kilograms, and most likely walked on two legs most of the time. The upper beak is formed by a tiny bone called the rostral, which is unique to the high, narrow skull. The cheek extensions resembled horns, and the skull stretched to a beak that lacked teeth, and the top jaw curled over the lower, giving the dinosaur its name. The anterior section of the skull had a morphology somewhat similar to a parrot’s beak, and the skull of the Psittacosaurus was unusually deep. These bipedal ceratopsians possessed four digits on each of their longer hind limbs and shorter forelimbs. Their tail was accompanied by quill-like structures that may have been employed for swimming or for show. The tail has also been shown to contain curly feathers, while their bodies were partially feathered and covered in leathery scales (particularly the tail). Researchers discovered that the color of Psittacosaurus included tones of chestnut brown, black, and yellow by examining one specific specimen of this ceratopsian. They were powerful crawlers as hatchlings and would have used all four legs to walk. When they were completely grown, they preferred to stand up straight on their rear legs only, while Its huge feet and robust tail suggest that it may have been a powerful swimmer. Psittacosaur abdominal cavities have occasionally been found to contain gastroliths, which can sometimes number over fifty. These stones may have been kept in a gizzard like modern birds do today. They were able to move at a remarkable speed while avoiding predators thanks to the existence of shorter forelimbs and longer hind limbs. The approximate lifespan of this ceratopsian, according to paleontologists, was 10 to 11 years.

Due to the fact that these dinosaurs were semi-aquatic, it is likely that they favored a riverine environment, other researchers, however, contend that they were more terrestrial in nature. These dinosaurs were herbivores, mostly consuming nuts and tree components, and the self-sharpening teeth of psittacosaurs would have been effective for cutting and cropping hard plant material. They lacked teeth that might be used for food grinding or chewing, in contrast to later ceratopsians. Gastroliths were utilised as an alternative.  Predation by larger animals and the numerous natural disasters that the Cretaceous epoch experienced are likely to have been the two main causes of their extinction.