Naashoibitosaurus

Image source: Naashoibitosaurus by cisiopurple

Naashoibitosaurus (nah-ah-sho-ee-BEE-to-SAWR-us) is a hadrosaurid dinosaur that lived during the Late Cretaceous in the Kirtland Formation of the San Juan Basin in New Mexico around 73 million years ago.

Naashoibitosaurus measured 30 feet (10 metres) in length and must have weighed around 2 – 3 tons. It was a huge duck-billed dinosaur who had a flattened head and a low nasal crest that peaked in front of its eyes. Naashoibitosaurus large hind legs and smaller front legs with hoof-like toes. It tail was long, heavy and stiff and would have been used to counter-balance when rearing up on its hind legs to feed on higher vegetation.

As a hadrosaurid, Naashoibitosaurus would have been a large bipedal/quadrupedal herbivore, eating plants with its specialized skull, grinding tough plant material with its many cheek teeth. Its teeth were continually replacing and self-sharpening. Plant material would have been cropped by its broad beak, and held in the jaws by a cheek-like organ. Feeding would have been from the ground up to 13 feet (4 metres) above.

Nanshiungosaurus

PaleoNeolitic, CC BY 4.0, via Wikimedia Commons

FURTHER READING AND STUDY

• Dong (‬1979). Cretaceous dinosaurs of Hunan, ‬China. ‬Mesozoic and Cenozoic Red Beds of South China
• Dong & ‬ ‬Yu (‬1997). A new segnosaur from Mazongshan area, ‬Gansu Province, ‬China.
• Lindsay (2010). A taxonomic and phylogenetic re-evaluation of Therizinosauria

Nanshiungosaurus (nahn-shyung-oh-sore-us), often known as the ‘Nanxiong lizard,’ was a therizinosaurian herbivorous theropod dinosaur genus. It existed during the Cretaceous period and in populated Asia’s terrestrial areas, and its fossils have been discovered in places like Guangdong, and Gansu, in China.

Nanshiungosaurus lived between 112.03 million and 66 million years ago, and  paleontologists have discovered two separate specimens of Nanshiungosaurus, including the vertebral column and pelvis, but no skull fossil has yet been discovered. As a result, in reconstructions, the head shape is based on comparable dinosaurs. Dong Zhiming identified and characterized it as “Nanshiungosaurus brevispinus” in 1979.

Nanshiungosaurus was given the name “Nanxiong’s lizard” because of its small vertebral spines. One of the oddest dinosaurs was Nanshiungosaurus. It most likely walked on two legs and when it walked, it walked like a bird, with its arms curled against its body to keep the weight of its claws from tipping it over. It’s supposed to be a pot-bellied creature with stout hindlimbs and a sturdy frame. The arms’ claws are curved and flattened and Nanshiungosaurus was a large-bodied therizinosaurid with a body length of 5 m and a weight of 907 kg. 

The skeleton unearthed had five dorsal vertebrae, 11 cervical vertebrae, six sacral vertebrae, and a few ribs. The arches of the cervicals were shorter than those of the dorsal. It had a powerful body and strong hind limbs, and had a small head and big recurved claws on its arms that were flattened from side to side.

It developed a large keratinous beak and coarsely serrated teeth, and was a herbivorous dinosaur with a big stomach that collected plants with its beak and devoured them. The specimen also revealed that the cervical had small arches while the dorsal had expanded arches, indicating that this dinosaur had a long neck.

The neural arches in most cervicals are short, but they are longer in the dorsals, and the axis is highly intact and is 13.5 cm in length. With 18 cm (180 mm) long centra, the seventh and eighth cervicals are the longest, and the vertebral size narrows slightly posterior to them. Unlike the cervicals, the dorsal vertebrae centra are small and platycoelous, with an average length of 7 cm (70 mm). They’re also pneumatic, with shallow pneumatopores (air-filled pits) on the lateral surfaces.

Because the Nanshiungosaurus diet is herbivorous, the food of this animal was most likely plants and leaves.

Nanshiungosaurus was one of the last therizinosaur that lived in the late Cretaceous period.

Nedoceratops

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

FURTHER READING AND STUDY

• Scannella and Horner (2011). ‘Nedoceratops’: an example of a transitional morphology
• Andrew A. Farke (2011). Anatomy and Taxonomic Status of the Chasmosaurine Ceratopsid Nedoceratops hatcheri
• Riley Black (2011). Nedoceratops: To Be, or Not to Be?

Nedoceratops (ned-o-ker-ah-tops), a controversial genus of ceratopsid herbivorous dinosaurs from the Late Cretaceous period Lance Formation of North America that lived 67-65 million years ago, and is a controversial genus of ceratopsid herbivorous dinosaurs from the Late Cretaceous period. It’s only known from a single skull found in Wyoming, and its name, which means ‘insufficient horned face,’ refers to the skull’s lack of nasal horn. The single type species in this genus is N. hatcheri. This Late Cretaceous dinosaur from the Ornithischia group lived in the Lance Formation, which had a subtropical environment. In nature, it was herbivorous and reproduced by depositing eggs, and the eggs were most likely laid in a nest in tiny batches. The female may have been in charge of keeping predators away from the nest. 

When Nedoceratops are compared to modern-day rhinos and elephants, it measured roughly 9 metres in length, and weighed between 1814.3-2721.5 kilograms. Their life spans are expected to be comparable and as a result, their life expectancy could have been in the range of 50-70 years. Nedoceratops, also known as Diceratops, had a distinctive look that set it apart from other dinosaurs. Nedoceratops’ skull has a few distinctive characteristics. It is slightly larger than typical (1.8m in longest length) when compared to other Triceratops skulls, although its face is very short. The horns on Nedoceratops’ brow were virtually vertical in appearance, and there was also one small aperture in the parietal region of the frill enclosing the face, as well as two asymmetrical holes in the wing-like squamosal border of the frills. Some of these holes, on the other hand, were most likely caused by disease or injury, while others were just a result of regular bone growth. 

The lack of a nasal horn was undoubtedly the most remarkable trait of this dinosaur, which led to its naming and is still a source of contention about the genus’s validity. It walked on all four limbs and had a parrot-like snout, and the limbs weren’t particularly lengthy. The dinosaur had a robust physique and strong limbs, with three hooves in the forelimbs and four hooves in the hindlimbs, according to Triceratops fossils. As a result of their shared ancestor, Nodoceratops may have shared physical characteristics with Triceratops.

The herbivorous Nedoceratops dinosaurs were found in the wild and probably ate ferns and conifers that made up the local flora may have been a part of their diet. These dinosaurs’ beaks most likely assisted them in separating the leaves from the stems. Nedoceratops dinosaurs are very likely to have fought amongst themselves as well. Following the K-T extinction event, Nedoceratops became extinct at the end of the Late Cretaceous period.

Nemegtosaurus

Josep Asensi, CC BY-SA 4.0, via Wikimedia Commons

FURTHER READING AND STUDY

• Nowinski (1971). Nemegtosaurus mongoliensis n. gen., n. sp. (Sauropoda) from the uppermost Cretaceous of Mongolia.
• Currie et al. (2017). Rediscovery of the type localities of the Late Cretaceous Mongolian sauropods Nemegtosaurus mongoliensis
• Alexander & Lopatin (2019). A possible new specimen of the Late Cretaceous Mongolian sauropod Nemegtosaurus

The herbivorous sauropod Nemegtosaurus (Nem-egg-tow-sore-us) was also known as the “Nemegt lizard,” lived during the Cretaceous epoch and roamed Asia’s deserts. Nemegtosaurus got its name from the Nemegt Basin in the Gobi Desert, where a single skull was discovered. Its fossils have been discovered in Xinjiang, China, Tochigi Prefecture, Japan, and mnögovi, Mongolia, and it lived from the Coniacian period until 66 million years ago. The Saurischia (“lizard-hipped”) order of dinosaurs included Nemegtosaurus, which suggests that while Nemegtosaurus was not closely related to lizards, it did have pelvic bones that were comparable in shape. 

Nemegtosaurus was a Sauropod, a huge quadrupedal herbivorous (plant-eating) dinosaur with a long neck that belonged to a group of similar large quadrupedal herbivorous (plant-eating) dinosaurs. Paleontologists have discovered three separate remains, including a skull and mandible (lower jawbone), so reconstructions are tentative. The skull is long and low, with pencil-shaped teeth, similar to Diplodocoids. N. pachi and N. mongoliensis are two types of species of this genus.

The skull fossil was discovered in 1971, although vertebrae from the same time period were recovered in 1949. It would have lived beside a beautiful river delta with many diverse creatures and dinosaurs running through the ancient sands of the Gobi Desert. 

A scleral ring-like feature was observed on Nemegtosaurus’ skull, which is bone support for the eye found predominantly in reptiles. In comparison to current reptiles and birds, the dinosaur’s scleral rings suggest that it was cathemeral, meaning it was active for small periods of time during the day. The dinosaur’s body length is estimated to have been between 12.2-15.2 m long based on fossil research. The bottom angle of the teeth was acute, resulting in a chisel-like tip.

With such a lengthy body would have given excellent defense against predators like the Tarbosaurus. Long tails and necks helped researchers identify the dinosaur, which had a large skeleton structure weighing around 18143.7 kg. Some of the Nemegtosaurus dinosaurs were among the world’s largest animals at the time.

Although there are no plant remains from the Gobi, flowering plants became more diversified during the Late Cretaceous, though ferns and conifers were still more common in many habitats. It’s also unclear whether Nemegtosaurus grazed on low-growing plants or browsed high in the trees. The Nemegtosaurus lived throughout the Cretaceous Period’s Campanian to Maastrichtian epochs and died out at 72-68 million years ago which  makes the dinosaur one of the planet’s last Sauropods.

Neovenator

Fred Wierum, CC BY-SA 4.0, via Wikimedia Commons

• Hutt et al., (1996). The first European allosauroid dinosaur
• Stephen et al., (2008). The osteology of Neovenator salerii from the Wealden
• Chris et al., (2017). Complex neuroanatomy in the rostrum of the Isle of Wight theropod Neovenator salerii.

Neovenator (nee-oh-ve-nay-tor) was a large-bodied theropod carnivorous dinosaur that was also known as “new hunter,” and it lived during the Cretaceous epoch whilst roaming Europe’s terrestrial areas. Its fossils have been discovered in places like Gironde, France, and it lived between the Hauterivian and 125 million years ago. It was the first member of the Allosauroidea family identified in Europe. 

Paleontologists discovered two separate specimens, and it is known from a partial skull and postcranial remains that make up around 70% of the dinosaur. This genus’ type species is N. salerii and the type specimen stands at 7.5 meters, with the isolated bones suggests much greater individuals.

Despite its enormous size, Neovenator’s bones reveal that it had a slender, ‘gracile’ frame. This would have decreased weight and improved speed, implying a predatory lifestyle better adapted to quicker prey. N. salerii‘s holotype has many fractures including Mid-caudal vertebrae fusions, healed mid-caudal vertebra transverse process fractures; osteophytes affecting pedal phalanges, and healed gastralia rib fractures, some generating false joints, and scapula fracture. This signifies that it survived and recovered from several bone fractures. Teeth, front lower jaw, ribs, chevrons, belly ribs, snout bone, a large part of the vertebral column, a hind limb, pelvic bone, and one shoulder girdle were among the bones recovered from the Isle of Wight.

Neovenator has a few unique characteristics, according to several scientific descriptions. The nostrils are twice as long as they are tall and the praemaxilla has five teeth. Its ribs and back neck vertebrae were fused together, the nostrils are large, but this is not unusual. Carcharodontosaurids are known for having pneumatised rear spinal vertebrae, Allosaurus also has elevated paired nasal crests. 

It was discovered in 2015 that the front of Neovenator‘s snout features a sophisticated system of neurovascular canals that serve as sensory organs, which is assumed to be used for hunting prey in the water. It has a long tail that kept it balanced and the Neovenator’s eyes were extensions of the skull’s horns, and its mouth was filled with blade-like fangs.

Neovenator stood 7.6 meters tall and weighed 1,000 to 2,000 kg. An extensive plain with small flowing rivers is supposed to have been the dinosaurs’ home. Bracken and cycads, as well as a few trees, covered such places. Due to the warm and humid environment of the Cretaceous epoch, the ecosystem of these dinosaurs had quite a high temperature and humidity levels. The Neovenator is considered to have a natural lifespan of 23 years.

The speed of this dinosaur has been estimated to be around 20 miles per hour, was a carnivore, and one of the top predators on the planet. It has been shown that their diet consisted of tiny dinosaur flesh.

The Neovenator dinosaur was an apex predator with strong serrated teeth and a big body size, therefore it’s safe to assume it was highly violent. These theropods lived throughout the Early Cretaceous period and were considered to have died out during the Barremian period, which lasted 125 million years.

Neuquensaurus

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

FURTHER READING AND STUDY

• Alejandro Otero (2010). The appendicular skeleton of Neuquensaurus, a Late Cretaceous saltasaurine sauropod
• Salgado et al., (2005). A New Specimen of Neuquensaurus australis, a Late Cretaceous Saltasaurine Titanosaur from North Patagonia
• Bonaparte and Gasparini (1978). The sauropods of the Neuquén and Chubut Groups and their chronological relations

Neuquensaurus (New-kwen-sore-us) was a genus of saltasaurid Sauropod herbivore dinosaurs known as the “Neuquén lizard.” It lived during the Cretaceous epoch and roamed South America’s terrestrial areas, with its fossils having been discovered in Argentina, and Ro Negro (Uruguay), and it lived between 100.5 and 66 million years ago.

Palaeontologists have discovered 13 separate individuals, and practically the full postcranial skeleton of this species has been discovered. Neuquensaurus is one of the tiniest titanosaurs ever discovered, it’s thought that this dinosaur had armour-like osteoderms, with a femur of 0.75 meters in length, with an estimated length of around 26.24 feet (8 m).

It moved on its five-toed club-shaped feet, which were thick, straight, and muscular. It had slender forelimbs that terminated in pillar-shaped feet that could hold its weight.

It’s one of the well-studied Patagonian sauropods, and this species is distinguished by the presence of dorsoventrally flattened posterior caudal centra and a greatly developed fibular lateral tuberosity. The Sacrum of this Sauropod genus is made up of seven vertebrae, making it unusual among Sauropods. So far, the genus has two species: N. australis and N. robustus. The scapulae’s coracoids are about quadrangular in form, rather than the more common spherical coracoid and the scapula and the coracoid are co-ossified.

The appendicular skeleton of Neuquensaurus exhibits unique characteristics only shared with closely related titanosaurs, such as the prominent fibular lateral tuberosity, and the presence of an inter-muscular line on the femoral shaft, according to the anatomical analysis.

The vertebrae also tilt less posteriorly toward the pelvis, having been inclined much beyond their respective centrum at first. The dorsal of Neuquensaurus have two supplementary laminae that are missing in even near cousins. The sacrum of the Neuquensaurus is made up of seven vertebrae, making it unique among sauropods.

Neuquensaurus was known to live in forest or wooded environments. Neuquensaurus were herbivorous, meaning they only ate plants and vegetation and most likely picked wooded settings with plenty of flora and the ability to eat and browse through taller trees due to their height. Conifers, gingkos, seed ferns, cycads, Bennett Italian, ferns, mosses, and horsetails were probably among the plants it ate. 

Nigersaurus

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

The Nigersaurus belonged to several types of dinosaur including; the Sauropodomorpha suborder, Diplodocoidea superfamily, Rebbachisauridae family, and Nigersaurinae subfamily.

Nigersaurus was thought to be a member of the Dicraeosauridae family when it was discovered as its structure appeared to be similar to that of members of this particular family of dinosaur.

However, based on newly discovered fossil evidence, Paul Sereno reclassified the bones. The rebbachisaurids are the most primitive members of the Diplodocoidea superfamily, lacking the bifid neural spines found in the other species of dinosaur. Interestingly nigersaurinanians’ bones are hollow and filled with air.

You can read more about the dinosaur that had 500 teeth here.

Nipponosaurus

LadyofHats, Public domain, via Wikimedia Commons

FURTHER READING AND STUDY

• Suzuki et al., (2004). Nipponosaurus sachalinensis (Dinosauria; Ornithopoda): Anatomy and Systematic Position within Hadrosauridae.
• Nagao (1936). Nipponosaurus sachalinensis ‬- ‬A new genus and species of trachodont dinosaur from Japanese Saghalien.
• Nagao (‬1938). On the limb bones of Nipponosaurus sachaliensis Nagao

The name Nipponosaurus means “Japanese lizard” and is pronounced, “nip-on-oh-sore-us.” The generic name refers to Nippon, Japan’s Japanese name; it was the first dinosaur to be named after a discovery discovered on Japanese soil. In 1936, this dinosaur was given an official name and description. Nipponosaurus was a herbivore. It inhabited the terrestrial lands of Asia throughout the Cretaceous period and existed from 85.8 million years ago until the Maastrichtian Age.

Nipponosaurus is a Hadrosaurid dinosaur from the Lambeosaurinae subfamily of the Hadrosauridae family. Hadrosaur dinosaurs were known for their herbivorous diet and duck-billed skulls.

The holotype remains of this dinosaur were discovered on Sakhalin Island in the North Pacific. When the southern half of this island was under Japanese authority, remains of Nipponosaurus were discovered here between 1934 and 1937. The understanding of Nipponosaurus is based on a juvenile’s fragmentary skull and postcranial. A left maxilla with dentary, parietal, various isolated skull elements, thirteen cervical vertebrae, six dorsal vertebrae, two sacral vertebrae, a series of 35 caudal vertebrae, a left scapula, distal portions of both humeri, most elements of the lower forelimbs, an ischium, left ilium, and most of the hindlimbs are among the fossil remains found. Despite the poor quality of bone preservation, the skeleton is thought to be 60 percent complete.

The Nipponosaurus dinosaur was estimated to be 13 feet long based on its remains (4 m). The weight of a Nipponosaurus is estimated to be roughly 340 kg. According to its fossil remnants, this ‘Japanese Lizard’ dinosaur had a peculiar look. The presence of a shelf-like structure on the lower jaw, the presence of a vertical coronoid process from the lower jaw, and relatively short front legs are some of the group’s distinguishing features. The skull of this dinosaur was typical of duck-billed dinosaurs. It had a hollow head crest at the top of its nose as well, and this dinosaur’s pelvic bones were similar to those of modern birds. Nipponosaurus was an oviparous dinosaur that reproduced by producing eggs. In general, hadrosaurs lived about 25 years on average. As a result, Nipponosaurus may have had a comparable lifespan.

The Upper Yezo Group fossils have given researchers with some information about this dinosaur’s ecology. It was most likely found in low-lying plains near the coast. This species’ herbivorous diet was facilitated by the presence of enough terrestrial plants in these locations. They most likely ate the range of plants that surrounded them in their native habitat. It’s possible that they were grazing or browsing. Hadrosaurs, notably Nipponosaurus, used their duck-billed heads to nibble off twigs and leaves.

Researchers’ computer models imply that hadrosaurs’ crests were employed to make low-bellowing cries as a type of mating call or possibly to warn each other about predators. Hadrosaurs were generally fast-moving creatures. According to some estimates, certain hadrosaur species might even outrun the enormous Tyrannosaurus rex. Given its herbivorous diet, it’s likely that this dinosaur wasn’t particularly violent. Natural calamities most likely wiped out this dinosaur during the Late Cretaceous period.

Noasaurus

Debivort, CC BY-SA 3.0, via Wikimedia Commons

FURTHER READING AND STUDY

• ‬Bonaparte & ‬Powell (1980). A continental assemblage of tetrapods from the Upper Cretaceous beds of El Brete, ‬northwestern Argentina
• Agnolin & ‬Chiarelli (2010).  ‬The position of the claws in Noasauridae (‬Dinosauria: ‬Abelisauroidea) ‬and its implications
• Paul (1988). Predatory Dinosaurs of the World

Pronunciation and meaning:

The name Noasaurus means “Lizard of Northwestern Argentina” and is pronounced, “noh-ah-sore-us.” The generic name begins with an abbreviation of noroeste Argentina, which means “northwest Argentina.”  Bonaparte and Powell named and found it in 1980. Noasaurus was a carnivorous dinosaur. It existed from the Maastrichtian Age to 66 million years ago and occupied the terrestrial areas of South America during the Cretaceous period. It was a tiny theropod that lived during a period when some of the world’s largest dinosaurs roamed the earth.

The genus Noasaurus is the type genus of the noasauridae, a ceratosaurian theropod dinosaur family. This genus’s type of species is N. leali. Its remains were discovered in a stratum of the Lecho Formation in Salta Province, Argentina, dating from the late Cretaceous period, namely the early Maastrichtian stage, approximately 70 million years ago. A fragmentary skeleton with a cranium makes up the specimen. The maxilla, quadrate bone, two neck vertebrae, two neck ribs, the centrum of a back vertebra, two hand claws, a finger phalanx, and the second right metatarsal bone are all contained inside it. Initially, one of the hand claws was mistaken for a second toe claw. It was identified as a hand claw in 2004. In 1999, an oviraptorosaurian neck vertebra discovered at the site was recognized as belonging to the Noasaurus holotype.

The Noasaurus leali was a tiny dinosaur that lived during the Cretaceous epoch. It was 3 meters long and 3.3 feet tall (1 m). They grew to be twice as long as a wild goat and twice as tall as a Labrador retriever. This dinosaur was smaller than humans, weighing 38 kg and being two times lighter than an adult. This dinosaur jaw from northern Argentina included at least 11 recurved teeth with serrations on the front and back edges. They had a long neck and tail, as well as extended neck vertebrae. Their vertebral and spine structure was a common feature among its relatives. The dinosaur’s foot was discovered to have a sickle-shaped claw at first, and it was then discovered that the claw belonged to a hand. Its claw was sharply curved, with parallel base sides in top view and a large triangular depression at the claw’s base. The bones and skull of the specimen are incomplete. They discovered the dinosaur’s claw, which was a distinguishing trait. They had a distinct breeding season, were oviparous, and lay eggs in the same way that modern birds do.

This dinosaur’s particular environment is unknown, but most dinosaurs lived near ancient rivers or streams, as well as woodlands and deep forests. It is known that they ate carnivorous foods based on teeth discovered in the jaw. Carnivorous dinosaurs ate a wide variety of prey, including smaller dinosaurs, tiny animals, and eggs. They would have killed or held their prey with their claw.

They could communicate with the rest of the herd or warn rivals of their area using closed-mouthed sounds of a lower frequency. Their claw might possibly play a role in mating displays or rivalry. These Theropod dinosaurs were relatively aggressive because they lived a carnivorous lifestyle, yet they were preyed on by other carnivores due to their tiny stature. They went extinct at the end of the Mesozoic epoch during the late Cretaceous–Paleogene mass extinction.

Nodosaurus

Conty, CC BY 3.0, via Wikimedia Commons

Nodosaurus (no-doh-SORE-us) was a genus of ankylosaurian dinosaur that lived in the Albian Age during the Lower Cretaceous period 70 to 110 million years ago in the woodlands of North America.

Nodosaurus measured 13 – 20 feet (4 – 6 metres) in length and weighed around 1 ton. It was a large bulky ornithischian (bird-hipped) dinosaur with bony dermal plates covering the top and sides of its body. It may also have had spikes along its sides. It had 4 short thick legs and 5 toes on each feet. Nodosaurus had a short neck, and a long, stiff tail that was club less. Its head was narrow, with a beak and it had small teeth. It was a quadrupedal dinosaur and moved around on all 4 legs. Nodosaurus had a very small brain and moved around very slowly.

Nodosaurus was a herbivore and would have eaten huge amounts of plants. It ate low-lying plants, like ferns and cycads, with its leaf-shaped teeth.

Nomingia

Smokeybjb at English Wikipedia, Public domain, via Wikimedia Commons

Nomingia (no-MIN-gee-ah) was an oviraptorosaurian theropod dinosaur who lived in the Maastrichtian era during the Late Cretaceous period, around 70 – 65 million years ago years ago in the woodlands of Mongolia, China in Asia. Relatives of Nomingia include Caudipteryx, Oviraptor and Protarchaeopteryx.

Nomingia measured 5 feet (1.6 metres) in length, its weight is unknown. It had long legs with clawed feet and claws on its hands, a beak and was covered in feathers. Nomingia took its birdlike attributes one step further than most other dinosaurs, as it is the only dinosaur that has yet been discovered to have been equipped with a pygostyle which is a fused structure on the end of its tail, a structure all birds have. This is the type of bone that birds have so their tail feathers can attach to their bodies. These pygostyles are used for displaying and attracting mates.

Nomingia was an omnivore and ate both meat and plants.

Nothronychus

Cc-by-3.0, CC BY 3.0, via Wikimedia Commons

FURTHER READING AND STUDY 

• Kirkland & Wolfe (‬2001). First definitive therizinosaurid (‬Dinosauria; ‬Theropoda) ‬from North America
• Zanno et al., (‬2009). A new North American therizinosaurid and the role of herbivory in ‘‬predatory’ ‬dinosaur evolution.
• Hedrick et al., (2015). The Slothful Claw: Osteology and Taphonomy of Nothronychus mckinleyi and N. graffami and Anatomical Considerations

The genus name Nothronychus means “slothful claw” and is pronounced “noh-thron-i-kus.” Palaeontologists named this odd dinosaur in 2001. Nothronychus was a herbivore that lived in North America during the Cretaceous period, from the Cenomanian Age until 89.3 million years ago.

Nothronychus were large theropod dinosaurs belonging to the Coelurosauria, a theropod group dominated by predatory dinosaurs known as therizinosaurs. This genus contains two species: N. mckinleyi and N. graffami. This Late Cretaceous dinosaur was discovered in the Zuni Basin, which is located between Arizona and New Mexico. It was the first confirmed therezinosaur discovery in North America. Nothronychus’ fragmentary skull and postcranium have been discovered. The fossil is also incomplete, with just fragments of the skull, a few vertebrae, and sections of the shoulder joint, hip, and hindlimbs, as well as a few other fossil parts. After its massive, sloth-like claws, it was given the name Nothronychus. The first Nothronychus fossil, however, was called an ischium. The type specimen for Nothronychus graffami was discovered in a marine deposit, which is an intriguing side point. It’s possible that this strange dinosaur evolved from a carnivore to a herbivore.

Nothronychus was nearly the same size, with a length of 4.2 meters and a weight of 900 kilograms. It was a big, ‘pot-bellied’ dinosaur with leaf-shaped teeth, a long neck, a tiny skull, and stocky hindlimbs. Despite the fact that some had feathers, they were nonetheless closely related to the dinosaurs that gave birth to the first birds. Claws up to 30 cm long, curved, and very sharp are seen on the long arms and agile hands and have four slender, tapering digits. The tail was also made shorter yet more flexible. Its inner forearms, chest, and bottom neck were apparently devoid of feathers. They walked on two thick, powerful rear legs, but they were unlikely to travel quickly. It had a short, stocky tail that likely helped it stay balanced on its back legs. They reproduced by depositing eggs and were oviparous. The newborns of these dinosaurs have sharp nails on their fingers but no wings in their skeleton, like their feathered relatives.

Nothronychus ate a range of plants and lived in a tropical rainforest setting. This herbivore spends most of its waking hours plucking and consuming massive amounts of leaves. Their claws appeared to be threatening, but they were actually designed to grab branches and pull them closer to the gluttonous herbivore’s little head. Paleontologists think that their claws would have been employed to hook around trees to ease feeding, similar to how sloths use their long claws to achieve the same thing nowadays.

Their claws may be used as lethal weapons if they were threatened. Given their size and food requirements, living with similar animals would have been extremely difficult, simply because the area’s ecology would have been decimated. Natural calamities are thought to have wiped out Nothronychus around 89 million years ago.

Nqwebasaurus

IJReid, CC BY 4.0, via Wikimedia Commons

FURTHER READING AND STUDY

• Jonah et al., (2012).  New information on Nqwebasaurus thwazi, a coelurosaurian theropod from the Early Cretaceous Kirkwood Formation in South Africa
• Klerk et al., (2000). A new coelurosaurian dinosaur from the Early Cretaceous of South Africa
• Scott Reid (2019).  Nqwebasaurus thwazi

The genus name Nqwebasaurus means “Nqweba lizard” and is pronounced, “n-qu-web-ah-sore-us.” Nqwebasaurus gets its name from the Xhosa term “Nqweba,” which is the local name for the Kirkwood district, and “thwazi,” which means “quick runner” in old Xhosa. Due to its discovery in Kirkwood, Nqwebasaurus has earned the unofficial nickname “Kirky.”

Nqwebasaurus was a meat-eating dinosaur. It inhabited Africa throughout the Cretaceous period and existed from the Berriasian Age until 132.9 million years ago. Nqwebasaurus was discovered in the Eastern Cape, South Africa, in the Upper Kirkwood Formation. The Nqwebasaurus was a theropod or coelurosaur that looked like a bird. It is classified as a member of the Ornithomimosauria clade. In this genus, N. thwazi is the type species.

Nqwebasaurus is one of the most primitive Ornithomimosaurs, demonstrating how the group evolved at the beginning of the Cretaceous period. Its fossils have been discovered in locations like the Eastern Cape (South Africa). Because Nqwebasaurus is only known from a fragmentary skeleton without a skull, the head shape is based on that of other dinosaurs. Because the original specimen was most likely a youngster, it was able to grow larger.

It is one of the oldest known Ornithomimosaurs, a dinosaur group that evolved to resemble extant Ostriches with longer tails. Its size was estimated to be between 2.9-3.3 feet long, and 1 foot tall, and weighed roughly 4.5 kilograms. It possessed lengthy arms with three long fingers on each, at least one of which was opposable. The fact that the first two claws on each foot were bent backward, but the claw on the third toe was not, was an interesting discovery. It also possessed fewer teeth, indicating that it was a relatively basic dinosaur, as well as gastroliths, indicating that the Ornithomimosaur group evolved to support unusual beaks. Nqwebasaurus would have had feathers as well, both fluffy ones for staying warm and longer ones on the arms that resembled wings, allowing Nqwebasaurus to flaunt them. It had a shorter, but not short, neck, and was squatter in general, compared to later members of the group. This dinosaur was bipedal in nature, as its forelegs were shorter than its hind legs. Their fossil revealed that it possessed incredibly light, hollow bird-like bones, as well as feet, specialized for quick running, according to researchers. They were oviparous.

They resided in a low-lying river system that was rich in mud and sand and overrun with plants, creating a wooded environment. Nqwebasaurus was originally thought to be a meat-eater, however, the discovery of gastroliths and a lower tooth count suggest that it was a herbivore. So they were omnivores because they ate both leaves, basic plants, and grass, as well as smaller creatures and fish.

They probably preferred to live in groups. Raising the front legs, stomping, and tail whipping were likely used as visual displays for communication. They were most likely quite aggressive due to their predatory nature. Because of their small size and quickness, it’s likely that these dinosaurs were highly chaotic, regardless of their food, and that they had to be quite aggressive to protect themselves.

They went extinct at the time of the Early Cretaceous period’s Valanginian era (due to natural disasters and extreme climate changes), which ended around 132.9 million years ago.