| Name | Lystrosaurus | Diet | Herbivorous |
| Name Meaning | “Shovel Lizard” | Height | 1 meters (3.2 feet) |
| Pronunciation | Liss-tro-sore-us | Length | 0.6-2.5 meters (2-8 feet) |
| Era | Paleozoic/Mesozoic – Late Permian – Early Triassic | Weight | 0.05-0.1 short tons (100-200 lbs) |
| Classification | Synapsida, Therapsida, & Anomodontia | Location | Africa, China, India, Mongolia, European Russia, Antarctica |
Lystrosaurus Pictures
The Lystrosaurus
Lystrosaurus is a type of therapsid that lived during the late Permian and Early Triassic periods around 250 million years ago.
In their time period, Lystrosaurus was one of the most common terrestrial vertebrates before going extinct and even managed to survive one of Earth’s most severe mass extinction events.
As a member of the Theraspida clade, Lystrosaurus shared many traits seen in modern mammals and early mammalian ancestors.
These animals were not dinosaurs but were classified into the Dicynodontia clade and were a type of mammalian reptile.
Discovered in 1969, Lystrosaurus have been found spread across late Permian and Early Triassic fossil beds and were one of the many fossils that helped support the theory of the supercontinent Pangea.
These animals have been found around the globe in places like Africa, China, Russia, India, and Antarctica.
Here you will learn about the pig-like herbivores that lived millions of years ago and the amazing things paleontologists have learned about Lystrosaurus through the fossils they left behind.
Physical Characteristics
Lystrosaurus size varied depending on the species, but overall these animals had a length ranging from the size of a small dog to up to 8 ft.
Today there are only around 4 to 6 Lystrosaurus species recognized, and the largest and most evolved of them is L. maccaigi.
The size of Lystrosaurus ranged between 0.6 to 2.5 meters (2 to 8 feet.)in length, and on average, these animals grew to around 0.9 meters (3 feet).
The weight of Lystrosaurus also varied, and they typically weighed between 50 to 90 kilograms (100 to 200 lbs).
These creatures walked on all fours, and their leg position gave them a semi-sprawling gait as they walked.
Lystrosaurus had a robust body, with a barrel chest and eyes positioned high on their heads due to their short jaws.
Compared to other therapsids, Lystrosaurus did not have any teeth but two tusks that were on the sides of their mouth.
The mouths of Lystrosaurus were beaked, similar to turtles or birds.
Fossil evidence and their overall abundance in their time periods have allowed paleontologists to make constant discoveries about how this genus looked and what traits possibly contributed to their survival during Earth’s greatest extinction event.
One of the most recent discoveries in 2022 showed that Lystrosaurus had leathery skin that was dimpled and hairless.
Habitat and Distribution
Lystrosaurus lived at the very end of the Permian age, until the beginning of the Triassic, and was the dominant species of its time on Pangea.
Pangea is a supercontinent made up of all of earth’s landmasses, which was formed at the start of the Permian age around 299 million years ago, and only started to break apart in the Early Jurassic period around 200 to 174 million years ago.
While the continents were all considered one during the time of Lystrosaurus, fossils from this animal have been found around the globe in modern-day Russia, Mongolia, India, China, and Antarctica.
Fossil sites of Lystrosaurus help support the theory of Pangea, and Africa is where Lystrosaurus have been found most, and their discoveries become more scattered in Asia.
Southern Pangea, also called Gondwana, is where Lystrosuarus was most abundant.
In Pangea during the Triassic period, the interior regions of the landmass were mostly desert due to the elevated land masses and lack of mountains.
In places with higher latitudes, coniferous forests began to dominate, and mosses and ferns could be found near the coastal regions.
Northern and southern regions of Pangea are thought to have a wetter, tropical rainforest environment.
Behavior and Diet
Lystrosaurus was a herbivore that fed on small low, lying plant life.
Since Lystrosaurus did not have teeth, they relied on their beak to chew their food.
The jaws of Lystrosaurus were very weak and moved back and forth in a shearing motion to help them cut through their food.
Since Lystrosaurus lived all across Pangea, they were adapted to feed on the various plants that were around, which could have contributed to their survival during the mass extinction event at the end of the Permian Epoch.
Dicroidium, Thinnfeldia, horsetails, and seeds from trees like ferns are some of the plants this herbivore ate, and they grazed around looking for food to eat.
The face and tusks of Lystrosaurus helped them dig out food from the ground and also supported the theory of their burrowing lifestyle.
Studies suggest Lystrosaurus hibernated in periods of extreme weather, which also could have helped them survive after the Great Dying occurred.
The ability to hibernate is why some scientists think Lystrosaurus was able to survive the great extinction even at the end of the Permian period since they could have remained inactive in times of little food and still survived.
Life Cycle
Lystrosaurus are dated to the Middle Permian period and went extinct during the Middle Triassic period.
The life cycle of Lystrosaurus became expedited, and fossil evidence suggests they reached sexual maturity quicker, helping them more efficiently populate the earth.
Before the Great Dying occurred, Lystrosaurus had a life expectancy of around a decade, but after it occurred, their life expectancy shortened to only a couple of years.
Fossils of Lystrosaurus after the Permian event had fewer growth lines, and more disorganized blood vessels and tissues, suggesting they grew very quickly and died young.
Lystrosaurus was one of the few tetrapods to survive the devastating event the earth underwent long ago, and some of the theories as to why they survived are their ability to hibernate, feed on various plant materials, and have large lungs.
The barrel chests and burrowing nature could have made it possible for them to breathe in and tolerate toxic air better than most animals, but other species that died off also had this trait.
Fossil evidence has been essential in learning the secrets of the Lystrosaurus, but there is still a lot to be learned about these animals, as it seems there was nothing special about them when compared with other animals of their time.
Evolution and History
The discovery of Lystrosaurus specimen was a skull discovered by Dr. Elias Root Beadle, and in the 1870s, he wrote to other paleontologists to discuss his findings.
During its discovery, its name was born, which is derived from the Ancient Greek words “listorn” meaning shovel, and “sauros”, which means lizard, referencing the animal’s shove-like face.
Lystrosaurus is known from a few species which include L. murrayi, L. declivis, L curvatus, and L. maccaigi.
Lystrosaurus is a member of the Dicynodonts family, which has been studied since the 1800s.
There are around 70 different genera within the Dicynodonts family, and they became extremely successful and were also diverse, as some were very small, while others were the size of elephants.
The clade of Theraspida includes Lystrosaurus and other Dicynodonts, and these animals roamed the earth from the Triassic to the Cretaceous periods.
It would be other Theraspids that would evolve into mammals, which would occur later in the Triassic after the demise of Lystrosaurus.
The extinction of Lystrosaurus is relatively unknown, but there are several theories which include overpopulation, other animals evolving to out-compete them, and a change in climate.
In the later Triassic period, volcanic eruptions occurred, and the overall climate shifted as Pangaea began to break apart.
The adaptability is what made Lystrosaurus able to survive, but with a reset of the world, other animals that also survived would adapt quicker once the earth began to stabilize.
Interactions with Other Species
Lystrosaurus lived in a unique time period since they survived the Permian-Triassic extinction and, at one point, accounted for up to 95% of life on Earth.
In the late Permian, Lystrosaurus lived alongside animals like Pelycosaurs and Cynodonts.
Cynodonts, Proterosuchus, and Gorgonopsids are the animals that preyed on Lystrosaurus before going extinct.
The mass extinction event that occurred killed nearly all animals and made it so that Lystrosaurus had very few natural predators, so the species began to grow.
After becoming one of the most common types of animals on earth, their demise would be brought on by climate change and other animals evolving to take their place.
Being such a larger percentage of earth’s animals, the extinction of Lystrosaurus likely made it possible for animals to fill the void they left.
Cultural Significance
Lystrosaurus is an important species, as they are one of the few animals to survive a mass extinction event.
Unlike birds, who are one the only dinosaurs to survive the asteroid extinction event and are still alive today, Lystrosaurus was not fortunate enough to maintain their populations.
There have been several discoveries made thanks to Lystrosaurus, as they better helped paleontologists understand Pangea and how animals can evolve to better survive extreme environments.
Lystrosaurus represents the early Triassic period and are featured animals in games showcasing prehistoric animals like Ark Survival, and can also be seen in museums.
There have been over 100 fossil specimens discovered of Lystrosaurus that give insight into how these animals could have survived such a destructive event and what the earth’s landscape looked like in the late Permian and early Triassic period.
Conclusion
Lystrosaurus is described as a mammal-like reptile and was one of the many therapsids that roamed the earth before reptiles; then, mammals took over.
What makes Lystrosaurus so unique is that they are not superpredators and dominate the world passively compared to other animals like dinosaurs and even humans.
Looking at the traits of Lystrosaurus, there was no real advantage that made them superior to other species, and their survival is overall attributed to luck and the power of evolution.
Lystrosaurus extinction is also interesting to study since they were one of the few animals to survive the Permian-Triassic extinction event, which killed an estimated 90% of life.
Going extinct so early in the Triassic period is surprising since, at one point, Lystrosaurus accounted for nearly 95% of life on Earth.
Lystrosaurus represents one of the many transition periods that Earth went through, and fossil evidence has been abundant, and found for hundreds of years.
With more fossils discovered and research done on ancient animals and the ecosystems they lived in over time, there will be a better understanding of the life that inhabited Earth millions of years ago.
FAQS
Did Lystrosaurus live in groups?
Evidence suggests that Lystrosaurus lived in herds, similar to modern animals today, like gazelles.
Fossils of many Lystorsaurus found together suggested they had herding behavior, and early Triassic beds in Africa are where they have been found in abundance.
After the extinction event of the Permian period there were a lot less Lystrosaurus roaming the earth, and living in herds helped them reproduce quicker.
Are there any descendants of the Lystrosaurus alive today?
While Lystrosaurus is closer related to mammals than reptiles, they are not ancestors to any modern animal today.
Lystrosaurus is a member of the Theraspid clade, and other members of this clade would later evolve into mammals.
Did Lystrosaurus have any defenses against predators?
Lystrosaurus did not have any traits that were solely for protecting itself from predators, but some of their behavior could have helped them survive attacks.
Lystrosaurus’s burrowing nature and ability to hibernate helped defend them from mass extinction events and also could have helped them escape attacks.
The main reason Lystrosaurus lacks any predatory defenses is they were the dominant species on earth when they lived, and lacked predators overall throughout most of their reign.
Sources:
- https://www.idunn.no/doi/full/10.1111/j.1502-3931.2007.00011.x
- https://pubs.geoscienceworld.org/sepm/palaios/article-abstract/32/6/349/506733/PALEONTOLOGY-OF-THE-BLAAUWATER-67-AND-65-FARMS
- https://peerj.com/articles/10408/?fbclid=IwAR26h3MPDiFlpbv-0qDijs4UiwL8r3NB3iSiVUkYHoINdOUJiuQ5FzMTgaM
- https://www.washington.edu/news/2020/08/27/faq-torpor-lystrosaurus/
- https://link.springer.com/article/10.1007/s12052-011-0349-y
- https://www.tandfonline.com/doi/abs/10.1080/02724634.2017.1365080
- https://earth.stanford.edu/news/what-caused-earths-biggest-mass-extinction
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