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Dinosaurs developed on a planet where there was only one supercontinent, called Pangaea, and only one ocean, called Panthalassa. Instead of the Atlantic Ocean, which was united to North America over a large portion of what would be today’s Atlantic coast, Africa was joined to that continent, creating the supercontinent’s desert and hostile interior.
The present-day Pacific coast was not yet present to the west. Instead, the region that would eventually become the states along the Pacific Ocean was either not yet a part of North America or submerged. There were no Rocky Mountains or the Colorado Plateau; instead, there were huge plains close to sea level. Volcanoes encircled the western edge of the continent.
South America provides the most substantial support for the earliest dinosaur forebears. Early in the Late Triassic, about 233 million years ago (Mya), actual dinosaurs began to form and disperse over the linked continents.
Dinosaurs were a minor component of the Late Triassic faunas, including a vast range of amphibians, reptiles, and relatives of mammals. Almost all of these other groupings would become extinct at the end of the Triassic, 201 Mya. Pterosaurs, marine reptiles, dinosaurs, relatives of modern mammals, and amphibians and reptiles all survived.
More Info on The Triassic Age
The Mesozoic Era‘s Triassic epoch was its initial stage. The earliest dinosaurs started to emerge in the Triassic era. Most were tiny, agile creatures who moved on only two legs. They weren’t all that different from their reptile forebears and were still preparing to take over as the preeminent terrestrial creatures throughout the Triassic Period.
Instead, a genus of reptiles called pseudosuchians that resembled crocodiles served as the primary predators. The class of reptiles classified as archosaurs included both the pseudosuchians and the dinosaurs. The dinosaurs wouldn’t surpass their archosaurian cousins in supremacy until the start of the Jurassic era, which came after the Triassic epoch.
The archosaurs maintained the evolutionary advantage for still-unknown reasons, outmuscling their “mammal-like” cousins and developing by the middle of the Triassic into the first real dinosaurs like Eoraptor and Herrerasaurus. On the other hand, some archosaurs took a different path, diverging to give rise to the earliest pterosaurs and a variety of ancestor crocodiles, some of which were two-legged vegetarians.
In the meantime, the size of therapsids decreased with time. Small, mouse-sized species like Eozostrodon and Sinoconodon served as the prototypes for the first mammals during the late Triassic epoch. Early marine reptiles flourished during the Triassic epoch due to the Permian Extinction’s depopulation of the world’s seas.
These contained the earliest plesiosaurs as well as a thriving species of “fish lizards,” the ichthyosaurs, in addition to unclassifiable, singular taxa like Placodus and Nothosaurus. In little time, the massive Panthalassa Ocean had been replenished with new varieties of extinct fish and elemental creatures like corals and cephalopods.
Despite not being quite as lush and green as the later Jurassic and Cretaceous periods, the Triassic saw an enormous increase in the number of different land-dwelling plants. There just wasn’t enough vegetation to support their growth, which is one of the reasons why there weren’t any large Triassic herbivores.
Triassic dinosaurs
Let’s look at some of the dinosaurs that graced the Triassic era with their presence. They are arranged in alphabetical order for easy scrolling.
Alwalkeria
- Dinosaur species type: Saurischian
- When it existed: Approx 228 Mya
- Where it was found: India
- Approximated average size: 1.6 feet
Alwalkeria was initially called Walkeria in 1986. However, it was subsequently discovered that the name of the genus was already used by a bryozoan, a type of microscopic aquatic invertebrate. Since the first creature to be called is usually given priority in naming, this required a name change, which is why Alwalkeria was changed in 1994.
It possessed a long tail that it utilized to sprint quickly and ambush its prey. Not much is known about the dinosaur Alwalkeria because of how incomplete and fragmented the holotype is. Alwalkeria was initially given the name Walkeria in 1986. However, the genus name Walkeria was subsequently discovered to be already used by the name of a bryozoan, a type of microscopic aquatic creature.
This required a name change since the first creature to be named is usually given priority in naming, which is why Alwalkeria was changed in 1994. Its long tail was useful for running quickly and ambushing its victim. Not much is known for sure about this dinosaur because of how fragmented and lacking the Alwalkeria holotype is.
Asylosaurus
- Dinosaur species type: Saurischian
- When it existed: Approx 201.3 to 208.5 Mya
- Where it was found: the United Kingdom, England
- Approximated average size: 6 feet 7 inches
A species of dinosaur from the Late Triassic of England is called Asylosaurus. The bones were first found in a Bristol cave fill from the Rhaetian era. An incomplete skeleton of the torso serves as the basis for Asylosaurus. Asylosaurus was also referred to by more bones that could be the same person.
After a reassessment by Peter Galton, the holotype remains of Asylosaurus were no longer assigned to the genus Thecodontosaurus and were instead assigned to a new genus. The genus name refers to how this collection of remains was transported from England to the United States and means “unharmed or sanctuary lizard.”
They would have been lost during World War Two when the museum section where they were being held was bombed if they had remained in England with the other Thecodontosaurus specimens. A genus of sauropodomorph dinosaurs known as Asylosaurus is the ancestor of the more sophisticated sauropods that would become widespread throughout the Jurassic period.
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Camposaurus
- Dinosaur species type: Theropod
- When it existed: Approx 220 Mya
- Where it was found: New Mexico and the USA
- Approximated average size: Unreliable estimates of length and weight exist
A Coelophysoid dinosaur from the late Triassic, Camposaurus is named after the reptile discovered by American paleontologist Charles Lewis and was thought to belong to the Herrerasauridae or the Coelophysoidae. In fact, for a little over ten years after the genus was described, there was a lot of conjecture that the genus was likely synonymous with the much more well-known Coelophysis because of how similar the Camposaurus looks to that species.
However, after research by Martin Ezcurra and Stephen Brusatte clearly revealed autapomorphies in the leg, which are not observed in Coelophysis, this idea was put to rest in 2011. The result is that Camposaurus is nevertheless different enough to be considered a separate genus despite having some superficial similarities to Coelophysis.
The first neotheropod dinosaurs, a subgroup of the Theropoda that would later give rise to all of the more complex theropod dinosaurs, are thought to include Camposaurus. Camposaurus would have been a tiny, lightweight predator that was likely focused on catching lizards and perhaps young dinosaurs in addition to smaller prey.
However, due to its diminutive size, Camposaurus would have had to avoid collisions with any potential larger dinosaurian predators, and most definitely with giant Rauisuchian that were hunting in the same areas and around the same time as Camposaurus.
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Chindesaurus
- Dinosaur species type: Saurischian
- When it existed: Approx 210 to 235 Mya
- Where it was found: the USA
- Approximated average size: 6.6 to 7.5 feet
The name Chindesaurus, which translates to “Lizard from Chinde Point,” comes from Chinde Point, which is close to the location in Arizona where Bryan Small found the original holotype specimen, or half skeleton, in 1985. It was first believed to be a sort of unidentified sauropodomorph dinosaur.
However, it wasn’t until much later that it was discovered that Chindesaurus truly constituted an early theropod dinosaur. It has been a little more difficult to determine exactly what sort of early theropod dinosaur Chindesaurus was. However, most scientists believe it was a relative of the more well-known Herrerasaurus.
During its time, Chindesaurus is believed to have been a tiny predator that preyed mostly on smaller creatures, maybe even smaller dinosaurs. Chindesaurus would have been among the quicker and more agile hunters compared to other predators of the period, which would have also been its greatest protection against them.
It has been suggested that Caseosaurus, a different early dinosaur genus described in 1998 (from specimens earlier ascribed to Chindesaurus), is really interchangeable with Chindesaurus.
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Coelophysis
- Dinosaur species type: Theropod
- When it existed: Approx 190 to 225 Mya
- Where it was found: South Africa and the USA
- Approximated average size: 9.8 feet
The earliest dinosaur discovered in North America is called Coelophysis. It was a meat-eater and possessed several traits that theropods that came after it lost. Although the fourth digit was fairly little, it possessed four fingers. Coelophysis possessed numerous tiny, sharp teeth, just like other early carnivores.
It’s clear that early dinosaurs demonstrated social behavior to the point of gathering in big herds. Although the precise reason for this massive convocation is unknown, some experts speculate that it could have been related to the mating season or the region’s plentiful food supplies.
A large number of dinosaurs, including all dilophosaurs, oviraptors, ornithomimids, and the well-known “Raptor” family, which includes Velociraptor, Utahraptor, and Deinonychus, are descended from Coelophysis. The Coelophysis skull was also the first dinosaur fossil to travel into orbit on the Space Shuttle “Endeavor” in January 1998.
Its short arms, head mounted on an “S-curved” flexible neck, and two legs that support its body from below rather than projecting out to the sides give it the unique theropod appearance. Additionally, some paleontologists believe that the later dinosaur Megapnosaurus was actually a Coelophysis that survived much later.
Support for this is provided by the two dinosaurs’ startling resemblance. The temporal range of Coelophysis would go beyond the Norian and well into the early Jurassic if it is established that Megapnosaurus is a synonym.
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Coloradisaurus
- Dinosaur species type: Sauropod
- When it existed: Approx 210 to 227 Mya
- Where it was found: Argentina
- Approximated average size: 13.1 feet
Sauropodomorph dinosaurs of the Massospondylidae family belong to the genus Coloradisaurus, which means “Colorado’s lizard.” It existed in what is now La Rioja Province, Argentina, during the Late Triassic era (Norian to Rhaetian stages). It may be identified because of a substantially complete skull holotype. It came from the top part of the Los Colorados Formation, where it was found and gathered.
Jose F. Bonaparte first gave the animal the name Coloradia in 1978, but this name had already been given to a moth. Thus the animal was given a new name. David Lambert initially gave the genus its name in 1983, and Coloradisaurus brevis is the type species. It could actually be a mature Mussaurus specimen.
Although it was a huge animal, Supersaurus and other sauropods were larger. Its neck and tail were quite lengthy. It had the ability to walk on all fours as well as its two hind legs. Due to its long neck, this herbivorous dinosaur mostly consumed the leaves of towering trees.
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Daemonosaurus
- Dinosaur species type: Theropod
- When it existed: Approx 201 to 208 Mya
- Where it was found: New Mexico
- Approximated average size: 5 to 7 feet
Fossils of the Daemonosaurus have been discovered in the Chinle Formation, which dates from the latest Triassic. Daemonosaurus is a basic theropod that exists outside the clade Neotheropoda, despite the fact that theropods had already diverged into multiple specialized families at this point.
A small skull and large, projecting teeth make Daemonosaurus unique among early theropods. Daemonosaurus has only been identified from a single specimen, which includes parts of its head, mandibles, atlas, axis, additional neck vertebrae, and ribs.
The Greek words “daimon,” which means “devil,” and “sauros,” which means “reptile,” are combined to form the generic name Daemonosaurus. The particular name is derived from the Greek word “chauliodus,” which refers to its procumbent front teeth and means “prominent toothed.”
All other Triassic theropods’ skulls differ greatly from that of Daemonosaurus. Large premaxillary and maxillary teeth are present in the upper jaw and are located on the short snout. From the points of the upper and lower jaws, procumbent teeth protrude forward.
Daemonosaurus features a kink in its upper jaws between the maxilla and the premaxilla, similar to the coelophysoids. Along with South American species like Eoraptor and Herrerasaurus, Daemonosaurus is part of a lineage that dates back to the Middle Triassic and the first dinosaur radiation.
In its original description, a phylogenetic study revealed that Daemonosaurus chauliodus was closely linked to the Neotheropoda and Tawa hallae. The first ornithischian, Daemonosaurus, was discovered to have numerous theropod-like traits.
Though only known from the postcranial skeleton, another dinosaur called Chindesaurus has been discovered in the same strata as Daemonosaurus. The intriguing topic of whether or not Chindesaurus and Daemonosaurus are the same has arisen as a result. The solution cannot be determined without more data from more comprehensive specimens.
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Eocursor
- Dinosaur species type: Ornithischian
- When it existed: Approx 201.3 to 237 Mya
- Where it was found: South Africa
- Approximated average size: 3 feet
An ornithischian dinosaur is called Eocursor. Eocursor was a bipedal dinosaur with a slim build. Its enormous hands resembled those of a group of early ornithischians called the Heterodontosauridae. Eocursor is not just one of the oldest ornithischian dinosaurs that are known, but it is also one of the best preserved.
Because of this, the genus has evolved into a sort of standard for researching early ornithischian dinosaurs. The shape of the triangular teeth, which resemble iguana teeth, indicates partial herbivory. It was a fast runner because the tibia was much longer than the femur.
The name Eocursor Parvus, which combines the Latin terms cursor (meaning “runner”) and parvus with the Greek word eos (meaning “dawn”), was given to the fossils (meaning “little”). Eocursor was one of the earliest dinosaurs with what are known as “bird hips,” a group that later gave rise to species including Stegosaurus, Triceratops, and Iguanodon.
Despite the fact that the ornithischian dinosaurs were largely herbivorous, there is some doubt regarding the Eocursor. The lower jaw’s teeth and the maxilla are arranged in closely spaced rows, making them ideal for digesting plants.
However, because the premaxilla’s teeth are pointed and conical, like those of a dinosaur that ate meat, it has been hypothesized that the animal may have been an omnivore. Even if Eocursor occasionally consumed meat, it was not an apex predator since it obtained its meal from a variety of sources, such as grabbing insects and tiny lizards as well as scavenging carcasses.
The back legs of the Eocursor are a solid indicator that it was a dinosaur that made it a point to avoid being eaten by predators. The lower leg bones are proportionally bigger than the upper leg bones, indicating that Eocursor was a bipedal dinosaur and had legs that were suitable for sprinting quickly. The name was partially inspired by this running adaptation.
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Eoraptor
- Dinosaur species type: Theropod
- When it existed: Approx 228 to 231 Mya
- Where it was found: Argentina
- Approximated average size: 3.25 feet
Eoraptor means “dawn thief” in Latin. Despite not having any connections to the Velociraptor or any other dromaeosaurids, the Eoraptor was given the name “raptor.” Compared to dinosaurs from later times, it had a very tiny body, like many early dinosaurs.
The Eoraptor was a biped that ran erect on its hind legs with forelimbs that were only half as long as its hind legs. Three of the five fingers on each of the forelimbs’ hands, which were thought to be employed to grasp and manage prey, terminated in huge claws. Similar to Herrerasaurus, Eoraptor had 18 teeth total, including 4 in the maxilla and 4 in the premaxilla.
Because of its bipedal stance and slim physique, Eoraptor was first categorized as a theropod. However, the sauropodomorphs also had a similar body plan when they were first evolving. This explains why Eoraptor had previously been classified as a theropod and a sauropodomorph.
In 2011 it was once again classified as a eusaurischid, putting it in the middle of these two families. The Eoraptor was thought to have devoured tiny animals owing to its quickness and keen claws, but it also had both herbivorous and carnivorous teeth, raising the possibility that it was omnivorous.
It was a quick sprinter, and once it caught its victim, it would tear it apart with its jaws and claws. It lacked a sliding joint at the articulation of the lower jaw, which would have allowed it to grasp huge prey, unlike later carnivorous dinosaurs. Paleontologists can’t agree on where to locate Eoraptor in relation to other dinosaurs, which makes it stand apart.
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Gojirasaurus
- Dinosaur species type: Theropod
- When it existed: Approx 210 Mya
- Where it was found: New Mexico and the USA
- Approximated average size: 18 feet
The name of the enormous Japanese movie monster “Gojira” (Godzilla) and the Greek word “sauros” were combined to get the phrase “Gojirasaurus” (lizard). The name “Gojira” was chosen to reflect the enormous size of this theropod, which was larger than its Triassic contemporaries.
One of the largest meat-eating dinosaurs from the Triassic Period is Gojirasaurus, which is almost as big as its relative, the enormous coelophysoid, Dilophosaurus. Its tibia was 469 mm, which is greater than those of Liliensternus and Dilophosaurus and indicates that the dinosaur was larger.
The jaws were packed with curved, serrated, blade-like teeth that were capable of slicing through both flesh and scaly skin. The stronger tibia of the Gojirasaurus allows it to be separated from its cousin, Coelophysis. The Coelophysoidea classification of Gojirasaurus would imply that it was a bipedal, terrestrial, actively mobile carnivore.
The phytosaur Rutiodon and the pseudosuchian Shuvosaurus were both Gojirasaurus’ contemporaries.
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Herrerasaurus
- Dinosaur species type: Early theropod
- When it existed: Approx 228 Mya
- Where it was found: Argentina
- Approximated average size: 9.8 feet
For the discoverer Don Victorino Herrera, the name Herrerasaurus translates to “Herrera’s Lizard.” It was the largest predatory dinosaur of its day. Herrerasaurus stood on its hind legs as opposed to the other enormous predators. It was an extremely vicious predator.
The flexible jaws of the Herrerasaurus allowed it to extend its mouth widely and ingest large pieces of meat. It has saw-like, perfectly serrated teeth. It has long hands but small arm bones as well. Some people believe that Herrerasaurus, with its bipedal posture and distinctive skull traits, is a primitive theropod.
Others in the field of paleontology believe Herrerasaurus to be a primitive saurischian. Additionally, some paleontologists believe that Herrerasaurus was an even more primitive dinosaur that existed before the first significant break between the saurischian and ornithischian dinosaur families.
The fact that Herrerasaurus possesses a variety of traits that are distributed across all dinosaur groups, despite the fact that the individual features are not present in each group, makes it difficult to make a precise identification. With the majority of other species, such as Eoraptor, Herrerasaurus was really one of the bigger dinosaurs that are presently known.
Although larger than other early dinosaurs, Suchosaurus was also active in the same region, suggesting that Herrerasaurus was not the dominant predator in its environment. With a similar dental configuration, Herrerasaurus already exhibits the fundamental theropod skull morphology.
In addition to smaller dinosaurs, Herrerasaurus most likely concentrated its hunts on tiny reptiles. Because of its large legs, Herrerasaurus would have been able to keep up with the smaller dinosaurs with ease, making it one of the few predators capable of catching them.
A sliding lower jaw is a cranial characteristic of the Herrerasaurus that is unusually absent in other dinosaurs. This sliding motion may have made it easier for Herrerasaurus to hold onto small prey while it fought in its jaws and may have also let it comb through larger prey.
Hunting tactics used by Herrerasaurus appear to have relied heavily on speed and agility. The legs, which have a proportionally small femur (the upper leg bone) and unusually lengthy lower leg bones, are the first indications of this.
The fact that Herrerasaurus walked on its toes and used its metatarsal foot bones to expand the length of its leg also contributed to its digitigrade gait, which lengthened its stride and raised its peak speed. The feet also demonstrate the evolution towards a three-toed foot since only one of the first and fifth toes had a claw, indicating that the other two were not utilized for additional traction.
Additionally, the pubis of Herrerasaurus points backward, a trait shared by birds and dromaeosaurid dinosaurs like Deinonychus that further hints at the need for agility. The arms are also fairly lengthy, suggesting that they may have been employed to grasp prey.
Liliensternus
- Dinosaur species type: Theropod
- When it existed: Approx 210 Mya
- Where it was found: Germany
- Approximated average size: 16.9 feet
Liliensternus was a bipedal, medium-sized carnivore that lived on the ground. The fragmented and partial skeletons of at least two individuals, including parts of the skull, lower jaws, vertebrae, and appendicular skeleton, make up the remains of two Liliensternus specimens that collectively make up a syntype series.
Unlike coelophysid taxa like Coelophysis, the tibia in both Dilophosaurus and Liliensternus is shorter than the femur. Liliensternus could be viewed as a transitional species between Coelophysis and Dilophosaurus based on its outward appearance.
Despite the fact that the skull is unknown, numerous reconstructions show Liliensternus to have a crest resembling that of Dilophosaurus. Like its contemporaries, Liliensternus possesses five fingers, but the fourth and fifth digits are smaller than the others.
This suggests that it may have existed between the five-fingered Triassic theropods and the three-fingered Jurassic theropods. A Liliensternus can be identified by the following characteristics:
- one pair of pleurocoels in the cervical vertebrae
- a less developed infradiapophyseal fossa
- the absence of a horizontal ridge at the base of the cervical neural spines
- the absence of a lateral bulge on the ilium.
The cervical vertebrae also have a broad, rounded ridge that extends from the posterior end of the diapophyses to the posteroventral. According to this interpretation, Liliensternus was an aggressive bipedal carnivore with the potential to hunt down bigger herbivores like Plateosaurus that were present in its paleoenvironment.
In order to stop prosauropods, Liliensternus employed its array of slicing teeth. It also used its speed to capture nimble ornithischians. Liliensternus, a huge theropod dinosaur from the late Triassic, measured more than five meters in length.
Because of its size, it is most likely that Liliensternus hunted sauropodomorph dinosaurs like Plateosaurus, yet it’s also possible that it also took smaller theropod dinosaurs. Typically, images of Liliensternus have a crested snout resembling that of the later Jurassic Dilophosaurus.
Lycorhinus
- Dinosaur species type: Ornithischian
- When it existed: Approx 195 to 205 Mya
- Where it was found: South Africa
- Approximated average size: 3.94 feet
Lycorhinus was once believed to be a cynodont, and it wasn’t until Alfred Walter Crompton analyzed the holotype in 1962 that it was determined to be a dinosaur. Many remnants were once ascribed to Lycorhinus, but the majority of them have now been assigned to other species in several genera.
One genus, Lanasaurus, identified by Christopher Gow in 1975, is now thought to be a synonym of Lycorhinus angustidens by paleontologists. Unfortunately, as Lanasaurus was based solely on a fragmentary maxilla, this has not significantly increased the number of Lycorhinus fossils known.
The term “wolf snout” refers to the fossilized dentaries and maxillae that make up the fossil material. Because it was initially mistaken for a cynodont and because of the precise description meaning “constricted tooth.”
Lycorhinus has three further species that have been named. Lycorhinus consors, Lycorhinus parvidens, and Lycorhinus tucki (formerly known as Heterodontosaurus tucki). The first two haven’t gained much notoriety, but James Hopson dubbed the last one Abrictosaurus in 1975.
It is believed that Lycorhinus angustidens was Heterodontosaurus’s companion. Alfred Walter Crompton didn’t realize it was an ornithischian dinosaur until 1962.
Melanorosaurus
- Dinosaur species type: Sauropodomorph
- When it existed: Approx 221 to 227 Mya
- Where it was found: South Africa
- Approximated average size: 26 feet
The name Melanorosaurus translates to “Black Mountain lizard.” Strong limbs indicate that it was moving on all fours. The group of dinosaurs known as Sauropodomorphs, sometimes known as “Prosauropods,” contains Sauropods and their near cousins. Melanorosaurus was a later Sauropodomorph.
Though technically not a Sauropod, Melanorosaurus shows how these quadrupedal behemoths developed from simpler dinosaur ancestors. Since Melanorosaurus possessed the omnivorous teeth of its ancestors, it is possible that it occasionally consumed small animals to augment its diet.
It was quadrupedal, yet its ungainly front feet still resembled its ancestors’ hands. The stronger hindlimbs and often pillar-like dimensions of the limbs helped support the animal’s enormous weight. In its habitat, it was likely one of the heaviest mammals.
Instead of having teeth like true Sauropods, it possessed a sharp, triangular snout and teeth like early Prosauropods. It had an extremely large trunk, a lengthy tail, and a small neck. It was big enough to have shed its fluff in an effort to be cool, yet it was also little enough to have some still.
It makes sense that some, if not all, of the warm fluff of its forebears may have been shed off, given that it lived in such a hot area. However, because it also resided in the south, it’s probable that Elliot had a colder climate than other Late Triassic locations.
Overall, as most renditions of Melanorosaurus are scaly, its position as fluff is up for debate. The term “sauropodomorph” is typically used to describe Melanorosaurus, while other sources place it in a different location.
However, Melanorosaurus represents a form that lies in between the later, larger quadrupedal forms and the bipedal sauropod ancestors. M. Thabanensis, a previous species of Melanorosaurus, has been transferred to the Meroktenos genus.
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Mussaurus
- Dinosaur species type: Sauropodomorph
- When it existed: Approx 203 to 215 Mya
- Where it was found: Argentina
- Approximated average size: 10 feet
The prosauropod dinosaur genus Mussaurus was a herbivorous species. The diminutive size of the skeletons that have been found so far gives it its name. Although it is somewhat misleading, Mussaurus is only known from fossilized juvenile and newborn skeletons.
Anatomical characteristics of Mussaurus point to a close, maybe transitional evolutionary link with real sauropods. Mussaurus is a noteworthy discovery because of its evolutionary importance and the insight it provides on prosauropod reproduction.
An excursion to the El Tranquilo Formation in the 1970s is when the fossils were initially found. The scientists discovered fossilized eggs and hatchlings there, which provided new information on Mussaurus and other prosauropod dinosaurs’ reproductive methods.
Despite having dimensions that would be exceedingly unusual for an adult prosauropod due to their early biological age, it was simple to determine that the specimens were prosauropods by looking at their limbs and pelvic bones.
Specimens of Mussaurus have been discovered near nests that are thought to hold many eggs each. Infant Mussaurus skeletons were tiny, resembling a medium-sized lizard in size. Adults and children have different proportions of size and mass. Young Mussaurus had towering heads, short snouts, and huge eyes, as was typical of dinosaurs.
Adults are anticipated to have longer snouts and necks and to resemble prosauropods more. Only juvenile animals were known of Mussaurus when it was initially described in 1979. However, when the adult was first reported in 1980, it was only categorized as a member of the Plateosaurus genus.
In 2013, they were re-evaluated, and Mussaurus is now also known from adult remains. Prior to this finding, the genus Coloradisaurus was hypothesized to be the likely adult form. It is believed that Mussaurus was predominantly, if not entirely, a plant eater. Sauropodomorphs and sauropods may have evolved together in the form of Mussaurus.
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Pantydraco
- Dinosaur species type: Sauropodomorph
- When it existed: Approx 2013 to 237 Mya
- Where it was found: the United Kingdom, Wales
- Approximated average size: 10 feet
The dinosaur genus Pantydraco, which means “Pant-y-ffynnon dragon,” belonged to the ancestral sauropodomorph family. Pantydraco gets its name from the words “pant” and “draco” in the Pant-y-ffynnon quarry, which both refer to arid valleys (a dragon or mythical dragon-like creature in Latin).
It is based on a fragment of a juvenile skeleton that was formerly believed to be a Thecodontosaurus’. Pantydraco is only recognized as having one legitimate species, P. caducus. Pantydraco had a medium frame and stood about the same height as an adult male.
The creature had a large hip joint and a lengthy tail that tapered off at the end. Its head was formed like a dragon and had a powerful jaw. The dinosaur’s forelimbs were designed for catching prey, while the rear limbs supported the weight of the animal.
The species was indeed bipedal since the center of mass is close to the pelvic bone. Shorter forelimbs than hind limbs were seen. Three of the hands’ digits could move, but the fourth was implanted. Its claws were well-developed.
It preyed on smaller creatures that could be taken down easily by the suppleness and agility of this dinosaur. The animal was quite graceful. The teeth had a healthy development. The bipedal Pantydraco moved by using its hindlimbs. Strong limbs supported the body well.
As a member of the sauropodomorph lineage, Pantydraco is thought to have most likely transitioned from carnivory to omnivory. Previously known as Thecodontosaurus caducus, Pantydraco. However, after a second look, several of the species were thought to be new or synonyms, as is the case with Pantydraco.
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Pisanosaurus
- Dinosaur species type: Ornithischian
- When it existed: Approx 216.5 to 228 Mya
- Where it was found: South America
- Approximated average size: 3.3 feet
The bipedal herbivore Pisanosaurus was a tiny, light-built creature that lived on the ground. Based on a skeleton found in Argentina’s Ischigualasto Formation, one species—the type, Pisanosaurus mertii—is recognized. For many years, experts have disagreed on the precise categorization of Pisanosaurus.
The tail of Pisanosaurus has been rebuilt as being as long as the rest of the body, based on early ornithischians. However, as a tail has not been recovered, this is speculative. It was only partially bipedal and most likely a herbivore.
There are various remarkable traits of Pisanosaurus. The hip joint, or acetabulum, is open. The ilium’s small pedicels contribute to the acetabulum’s modest axial length. In comparison to the pubic bone, the ischium’s top section is wider. The hand’s metacarpals, which are around fifteen millimeters long, appear to be extended.
The name Pisanosaurus, which translates to “Pisano’s lizard,” honors Argentine paleontologist Juan Arnaldo Pisano of the La Plata Museum, by combining the Greek word for “lizard” with the Latin suffix “saurus.” The type and only legitimate species known today is Pisanosaurus mertii.
Pisanosaurus has undergone several classifications throughout the years, including heterodontosaurid, fabrosaurid, hypsilophodont, and oldest known ornithischian. Eocursor, Trimucrodon, and maybe Fabrosaurus are some more early ornithischians. The idea that Pisanosaurus was a silesaurid resurfaced in 2017.
Pisanosaurus could have been a meal for the huge predator Herrerasaurus. One of the earliest ornithischian dinosaurs now known to science is Pisanosaurus. Unfortunately, because of how fragmented the holotype specimen is, characteristics like the pubic bone’s position are still a mystery.
Pisanosaurus is an excellent sign for a kind of dinosaur that would grow prevalent and widespread all the way through the Mesozoic because, despite this, the fundamental orithopod body form can still be readily visible.
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Plateosaurus
- Dinosaur species type: Sauropodomorph
- When it existed: Approx 204 to 214 Mya
- Where it was found: Europe
- Approximated average size: 16.4 to 33 feet
One of the final prosauropod dinosaurs to walk only on its hind legs was the Plateosaurus. It consumed plants, much like other prosauropods. However, it may have also consumed tiny invertebrates. A bipedal herbivorous dinosaur with a characteristic body form was Plateosaurus.
Even when compared to most other “prosauropods,” the arms were very short. They had strong hands that were designed for hard grabbing, nevertheless, and they were well-built. As in other basic sauropodomorphs, the shoulder girdle was narrow, with the clavicles meeting near the midline of the body.
The foot was digitigrade, which means it walked on its toes, and the hind limbs were held beneath the torso with slightly flexed knees and ankles. Plateosaurus was able to run swiftly, as evidenced by its relatively large lower limb and metatarsus.
The tail of Plateosaurus was strong and highly mobile, as was typical of dinosaurs. The skull was slender and rectangular from the side. Its length was almost three times as great as its height. Plant material might be crushed by the jaws’ many thin, leaf-shaped, socketed teeth with broad, sharply serrated tooth crowns.
Plateosaurus could administer a forceful bite thanks to the high leverage the chewing muscles had due to the low location of the jaw joint. Instead of looking in the front, its eyes were pointed to the sides, giving it 360-degree visibility to watch for predators.
Some scientists disagree with the notion that sauropods were directly descended from Plateosaurus. Almost every possible stance for Plateosaurus has been proposed at some time in the scholarly literature. Plateosaurus apparently did not employ gaits with airborne, unsupported periods, in contrast to running mammals.
They must have improved speed instead by using longer strides, which were produced by quick, forceful limb retractions. For non-avian dinosaurs, reliance on limb retraction rather than extension is characteristic. One of the earliest dinosaur genera, Plateosaurus is perhaps the best-understood sauropodomorph currently known.
The fact that Plateosaurus appears to have possessed an avian-like (or “bird-like”) respiratory system is one of the most shocking discoveries about it. This was initially suggested by an examination of the bone development patterns.
However, recent research on the front part of the postcranial skeleton shows that Plateosaurus would have possessed an air sac system resembling that of modern birds. Although there isn’t a strong argument that Plateosaurus lived in herds, there is also no evidence that they didn’t.
It has been hypothesized that large groups of Plateosaurus that were found in what were formerly muddy bogs were herds that got caught in a mudflow. Alternative theories state that since Plateosaurus was a herbivore, it’s possible that it traveled in loose herds, or at the very least, gathered in groups due to the availability of food.
Riojasaurus
- Dinosaur species type: Sauropodomorph
- When it existed: Approx 210 to 221 Mya
- Where it was found: Argentina
- Approximated average size: 33 feet
The herbivorous sauropodomorph dinosaur Riojasaurus, sometimes known as the “Rioja lizard,” was named for the La Rioja Province in Argentina. The only known riojasaurid to reside in South America is Riojasaurus. Riojasaurus had a long neck and tail, a massive body, and broad legs.
For an early sauropodomorph, its leg bones were huge and thick. In contrast, the hollow holes in their vertebrae made them lighter. Riojasaurus, in contrast to other early sauropodomorphs, possessed four sacral vertebrae as opposed to three.
It was believed that because it couldn’t rear up on its hind legs, it most likely walked slowly on all fours. A mandatory quadrupedal gait has been suggested by the approximately similar length of the fore and hindlimbs.
But in 2016, Scott Hartman discovered that Riojasaurus’s hand morphology, somewhat straight back, and essentially inflexible shoulder girdle supported its bipedal status. Riojasaurus has serrated teeth that were fashioned like leaves. The upper jaw had five front teeth and 24 more back teeth that stopped under the eyes.
The teeth suggest a preference for lush foliage in terms of diet. Riojasaurus’ scleral rings can be compared to those of contemporary birds and reptiles, indicating that it may have been cathemeral. This indicates that it was awake briefly both during the day and at night.
Riojasaurus was and still is frequently attributed as being related to Melanorosaurus, despite the fact that a thorough examination of the two taxa reveals important distinctions.
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Saturnalia
- Dinosaur species type: Sauropodomorph
- When it existed: Approx 233.23 Mya
- Where it was found: Brazil and Zimbabwe
- Approximated average size: 5 feet
It has been challenging to categorize Saturnalia due to its rudimentary nature and blend of sauropodomorph and theropod traits. Recent cladistic analysis, however, revealed that it was a very primitive sauropodomorph, perhaps a guaibasaurid, since the family was discovered to nest in a basal place within Sauropodomorpha.
The members of the sauropodomorpha would steadily evolve into the “true” sauropods, which would become one of the largest and most dominant types of plant-eating dinosaurs by the middle Jurassic. The theropods would remain one of the key groups throughout the history of the dinosaurs.
Sauropodomorph necks had already begun to lengthen in support of evolution. Additionally, although still being shorter than the hind limbs, the forelimbs appear to have been able to support their weight. Saturnalia was more likely to be quadrupedal in a regular resting posture, given the length of the real body and the combination of the two.
However, Saturnalia may have still been able to run on just two legs when evading predators and rear up on just its hind legs to extend its reach when feeding. Due to Saturnalia’s basal position within the Sauropodomorpha, the precise diet of this species is a little hazy.
Future sauropods will only consume plants, yet they were descended from carnivorous forebears. Saturnalia’s hands and head have more typical theropod characteristics, and the great majority of the taxa that belong to this group, particularly during the Triassic, are unquestionably carnivorous.
It’s not completely inconceivable that Saturnalia may have eaten tiny creatures or even scavenged meat, but it’s also feasible that it may have already converted to a diet that was primarily plant-based.
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Staurikosaurus
- Dinosaur species type: Saurischian
- When it existed: Approx 233.23 Mya
- Where it was found: Brazil
- Approximated average size: 7 feet 5 in
The name Staurikosaurus princei, which refers to both the dinosaur’s discoverer Llewellyn Ivor Prince and the constellation “The Southern Cross,” means “Prince’s Southern Cross Lizard.” Staurikosaurus and its much bigger relative Herrerasaurus shared a lot of characteristics.
These characteristics include a large, somewhat thin head with many pointed teeth and strong jaws to rip through the flesh it consumed. Staurikosaurus didn’t have forward-facing eyes, therefore it wasn’t able to observe its surroundings in great detail, despite the fact that it was probably able to see well.
Its comparatively long, thin body and neck were built to let it move swiftly, either to keep up with the small, swift prey it hunted or to outrun more powerful, deadly predators like the terrifying prestosuchus.
Long arms with grasping hands with five fingers and claws that resembled hooks allowed it to snare tiny prey. Staurikosaurus was a fast-moving dinosaur, as evidenced by its large hind legs. The legs of the staurikosaurus were likewise rather lengthy and had three toes with pointed talons on each one.
It possessed a long tail with more than 40 vertices that would have helped this sleek theropod balance while sprinting. Its tail was also elongated. This particular bipedal species would serve as the “blueprint” for dinosaurian predators over the following 128 million years, up to the end of the Mesozoic.
Staurikosaurus is a member of a group of dinosaurs that were extremely closely related to those that were ancestral, which does not imply that it was the progenitor of all subsequent theropod species.
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Thecodontosaurus
- Dinosaur species type: Sauropodomorph
- When it existed: Approx 201.3 to 203.6 Mya
- Where it was found: the United Kingdom, England
- Approximated average size: 6.5 feet
Small, bipedal Thecodontosaurus was an animal. It’s among the earliest dinosaurs ever found and the most ancient. Only one species, Thecodontosaurus antiquus, is still regarded as genuine today, despite the genus having seventeen further species identified in addition to the original type species.
The term comes from the Greek words thekè, meaning “socket,” and odous, meaning “tooth,” and refers to the fact that, unlike modern lizards, the roots of the teeth were located in distinct tooth sockets rather than being merged with the jaw bone. The particular epithet, “antiquus,” is Latin for “ancient.”
The Bristol Blitz in November 1940 destroyed a lot of this dinosaur’s remains and other related items. The majority of the bones were saved, nevertheless, and 184 of them are now in the Bristol City Museum and Art Gallery’s collection.
A rather short neck supported a fairly massive head with enormous eyes on the thecodontosaurus. Many tiny to medium-sized, leaf-shaped, serrated teeth were present in its jaws. The feet and hands of this dinosaur had five digits apiece, and the hands featured an extended claw on each.
This dinosaur’s tail was considerably longer than its head, neck, and body combined, and its front limbs were noticeably shorter than its legs. Thecodontosaurus is commonly regarded as the most primitive sauropodomorph dinosaur, despite not being the group’s first member.
Formerly classified as a member of the Prosauropoda, current research suggests that Thecodontosaurus and its relatives lived before the prosauropod-sauropod divide. According to recent reconstructions, its neck is proportionately shorter than that of earlier, more developed sauropodomorphs.
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That’s a Wrap!
Despite not being the period when dinosaurs were considered the dominating terrestrial animals, dinosaurs were nonetheless widespread throughout the Triassic. They also had a variety of functions, from the early Triassic small animal and mammal predators to the late Triassic enormous herbivores.
We really hope you’ve enjoyed reading about the incredible dinosaurs that existed during the Triassic Era. Please reach out if you have questions or ideas on things you’d like us to write more about. You can also discover even more about the different periods, the dinosaurs that lived in them, and the world beyond dinosaurs on our other pages:
- Find more on the Triassic Period https://ancientbeasts.com/dinosaur-history/triassic-period/
- Find more on the Jurassic Period https://ancientbeasts.com/dinosaur-history/jurassic-period/
- Find more on the Cretaceous Period https://ancientbeasts.com/dinosaur-history/cretaceous-period/
- Find more on the creatures Beyond Dinosaurs https://ancientbeasts.com/dinosaur-history/beyond-dinosaurs/
- Find more on Dinosaur Myths and facts https://ancientbeasts.com/dinosaur-history/dinosaur-myths/
