Meet Brontoscorpio. His kind may look like modern scorpions, but he's a meter long monster scorpion with gills, a superior armory to Anomalocaris, and a stinger the size of a light-bulb.
— Allen, about Brontoscorpio

Brontoscorpio (name meaning, "Thunder Scorpion") was a genus of eurypterid arthropod that originated during the Early Silurian era in what is now Europe. A large prehistoric sea scorpion measuring a meter long, it is notable for being one of the first animals to walk onto land. While this creature hunted ancient fish and other smaller sea creatures, larger predators in the waters in which it lived with would have in turn preyed on Brontoscorpio - including Giant Orthocones and even other sea scorpions larger than Brontoscorpio, especially Pterygotus.

In the episode entitled "Arthropods Round II", nearly a dozen Brontoscorpio were brought back to the park from 430 million years ago. They reside in an enclosure that is similar to the one the group of Anomalocaris live in.


Era & Discovery

Brontoscorpio lived during the Silurian period from 440 – 417 million years ago alongside Cameroceras, Cephalaspis, and Pterygotus. As a species of sea scorpions, Brontoscorpio was one of the top predators in the Silurian seas. Brontoscorpio was first discovered in 1972.

Physical Attributes

Brontoscorpio was a large, black-colored sea scorpion with large pincers. It resembled a modern scorpion, except measuring 3 feet (1 m) long, that it was far larger, had body armor stronger than Anomalocaris, possessed gills as well as primitive lungs and a bulbous tail with a stinger approximately the size of a light bulb. Its body was covered in a hard exoskeleton. The only soft spot Brontoscorpio had in its exoskeleton which could be exploited as a 'chink in its armor' was its open mouth.

Brontoscorpio also had 2 pairs of pincers, with the larger pair used for grasping prey and the smaller used for tearing it apart. Brontoscorpio had evolved strong jaws for crushing and tearing apart the tough armored body of its prey. Not only could it breathe underwater with gills, but Brontoscorpio could also come onto dry land and absorb air it with its primitive book lungs, which were made up of hundreds of thin layers of tissue. Being unable to breathe in and out as humans do, Brontoscorpio could only absorb oxygen into their bloodstream. 

Like some modern arthropods, Brontoscorpio had to molt if it grew too large for its exoskeleton. The process of escaping its body would take approximately a day to complete and afterward, Brontoscorpio would be vulnerable to attack as its skin would be soft. 

Equipped to maximize oxygen, and with their armor to protect them from the sun, these sea scorpions often patrolled the shorelines, scavenging on whatever the seas washed up. However, there were times where some Brontoscorpio couldn't feed because they often became prisoners in their own skin. Their rigid skeletons became a handicap and thus, it couldn't grow with their bodies. They needed to shed their hard skin and then grow another, expanding while the new one is still soft. For such a large creature, this was a long process.


Brontoscorpio's large stinger on its tail would inject deadly venom into other animals with one sting, which could weaken and paralyze stung prey and then kill them through causing heart failure. The symptoms of Brontoscorpio poisoning and the speed at which the venom took effect depended very much upon the dosage injected: a direct sting, such as a stab, would bring the victim down instantly and kill it within seconds, whereas an indirect sting, such as a shallow scratch, would gradually weaken, numb and then kill the stung victim over the course of a matter of hours.

Behavior & Traits

A species of sea scorpion and one of the apex predators of the Silurian, Brontoscorpio was a carnivorous predator and prey was plentiful in their seabed hunting ground. Their style of hunting was to stab its prey with its huge stinger and to inject it with highly toxic venom. The venom would paralyze the victim and with multiple jabs of the stinger, the prey would be dead within a matter of seconds.

Mainly a solitary animal, Brontoscorpio spent most of its time hunting small marine animals, such as trilobites and jawless fish like Cephalaspis, individually. However, they occasionally banded together in colonies during the Cephalaspis breeding season to catch Cephalaspis en masse. Although Brontoscorpio was a fierce and lethal predator in its own right, it too was a prey item and therefore it had its own predators. Larger eurypterids, like Pterygotus, and other predators such as Cameroceras included the scorpion on their menu.

Brontoscorpio was among the first animals to walk onto dry land. However, moving onto land for Brontoscorpio was a rare thing as most of its activity was underwater. One of the reasons this scorpion went onto dry land was to feast on Cephalaspis migrating to their spawning grounds. Another is that they came on land to escape predators and molt its shell.

Sometimes in their lives, Brontoscorpio would become prisoners in their own skin. Their rigid skeleton would become a handicap, and as such, it wouldn't have been able to grow with their body. Similar to a snake, Brontoscorpio would shed their hard skin and then grow another, expanding while the new one was still soft. At 3 feet long, it would take hours for a Brontoscorpio to molt its shell. An additional reason they were on land was that Brontoscorpio patrolled the shorelines, scavenging on any carcass that came from the sea.

Surprisingly, Brontoscorpio could also scale walls, ceilings, and other surfaces much like a spider. Brontoscorpio made their home in caves and burrows, and they also made use of hidden sinkholes across the land in their territory as sandtraps to trap unaware animals for the Brontoscorpio to come for, similar to Trap-Door Spiders.

Brotoscorpio would attack victims with its large stinger on its tail to inject and incapacitate them with its deadly venom in just one sting, which could weaken and paralyze stung animals such as humans, and then kill them through causing heart failure. Then, they would drag the attacked prey's body away to suck out and consume their internal organs after the venom killed them.

While Brontoscorpio preferred to attack prey that was either alone or off-guard, it would engage an organized group of other animals in a direct fight if it had to. Brontoscorpio displayed some similar caution and attack strategy to some modern-day scorpions; approaching prey tensed and cautiously, and momentarily backing away slightly at the movement, resistance, and aggression from the victim. 


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