While there were many bizarre animals during the Triassic period, there was nothing else quiet like Lotosaurus.
While it may have looked like a dinosaur, Lotosaurus was instead more closely related to crocodilians,
belonging to the larger clade Pseudosuchia.
A quadruped, Lotosaurus was about two and a half meters long and a little less than one meter tall.
While small, it was not built for speed, with a plumper body than most other Triassic pseudosuchians.
Unlike most of its relatives, its head was small and possessed a toothless beak, giving it a vaguely turtle-like appearance.
But its most prominent feature was its tall neural spines.
They are somewhat reminiscent of those that formed the sails of some early synapsids like Dimetrodon
like Spinosaurus
and Ouranosaurus
Lotosaurus was not the only pseudosuchian that possessed large neural spines.
Ctenosauriscids like Arizonasaurus also had elongated neural spines, which did form a sail.
However, Lotosaurus's neural spines were were shorter and wider than in these species.
This condition is closer to that of mammals that possess humps, like bison.
Therefore, Lotosaurus mmost likely possessed one as well, perhaps to store fat or anchor large muscles.
Assuming Lotosaurus did possess a sail, the primary hypothesis for why it,
and definitively sailed species, had them is that they were for used to attract mates,
like the many other bizarre features seen in both living
and extinct species.
While once thought to be for thermoregulation, more recent research has found that sails
would have been far less efficient in that role than once thought.
With its rotund body, Lotosaurus was ill-suited for catching mobile prey,
leading to it usually being reconstrcued das a herbivore.
This would explain its large abdomen. As plants are more difficult to digest than meant,
herbivores generally require more space for their digestive system.
Its beak seems to have had a strong bite force.
This would be helpful when consuming the tough vegetation common in most parts of the largely arid Triassic.
However, it would be less helpful when consuming the softer plants present in prehistoric wetlands
Lotosaurus’s fossils were preserved in.
This may be result of simple preservation basis, with Lotosaurus potentially being much more widespread.
Alternatively, the beak’s strong bite force may have evolved not to crush hard food items but instead to ward off predators.
Another possibility is that Lotosaurus was instead durophagous‭, a species that consumed hard shelled prey.
Specifically, it may have eaten shellfish, which are common in the same sediments Lotosaurus is found in.
With Lotosaurus's strong bite, opening their shells would not have been a problem.
For now, like so much else about it, the diet of Lotosaurus remains uncertain.
This is largely due to, despite how unique it is and the presence of several complete skeletons,
Lotosaurus remains heavily under-researched.
Despite being named in 1975, Lotosaurus has yet to even receive a full description.
Still, there is some insight into their social lives:
namely that they had social lives.
The only site with confirmed Lotosaurus fossils is a bonebed in the southern Hunan Province in China
China which contains at least thirty-eight Lotosaurus.
When Lotosaurus was alive, this area was subtropical with moderate rainfall and pronounced wet and dry seasons.
Since there are very few fossils of other vertebrates at the site, it seems that the Lotosaurus died, and most likely lived, together.
Unfortunately. the precise age of the site is unclear, which hampers understanding Lotosaurus’s evolutionary history
While most of the major landmasses where already part of the mega continent of Pangea by the start of the Triassic,
Lotosaurus’s home in what is now southern China remained an isolated subcontinent until the Middle Triassic.
The possible age of the Lotosaurus bonebed ranges from just before
to just after Southern China became connected with the rest of the world.
So did Lotosaurus evolve in isolation?
Or did it or its ancestors live elsewhere on Pangea
and only colonize southern China once it became linked with the mainland?
What is known is that Lotosaurus was a member of Poposauroidea.
While Poposauroidea contained many bizarre species, none of them looked very similar to Lotosaurus.
The previously mentioned ctenosauriscids were also poposauroids.
Because of its tail neural spines, Lotosaurus was once thought to be a ctenosauriscid itself,
though it is now seen as a more distant relation.
The closest known relatives of Lotosaurus were instead the nimble shuvosaurids.
Like Lotosaurus they had beaks and may have been herbivorous.
But even they differed considerably from Lotosaurus.
Like Poposaurus, the namesake of Poposauroidea, the shuvosaurids were bipedal.
As Poposaurus was the closest known relative of the clade formed by Lotosaurus and the shuvosaurids
This means that both the species more derived and more basal than Lotosaurus were bipeds.
This either means that Lotosaurus had a bipedal ancestor and later reverted to a quadrupedal stance
or that bipedalism evolved twice in Poposauroidea, once in Poposaurus
and again in the shuvosaurids.
Even among its closest known relatives, Lotosaurus was unique.
While a lot is still not known about it, what is known is certainly impressive.
Hopefully, a full description of Lotosaurus,
along with further discoveries and research will help us to learn even more about this fascinating reptile.
Thank you for watching. I hope you learned something interesting.
So what do you think about Lotosaurus?
Do you think was more likely a herbivore or shellfish eater?
And do you think it had a hump or a sail?
Be sure to leave your answer in the comments below.
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