Plague

The unnamed **plague** is a horrific, deadly infection capable of turning those afflicted with it into murderous zombie-like beasts. It is the primary cause of the infected Argentinosaurus's manic state in "Plague of Madness".

## Overview

### Symptoms

The plague causes a wide range of drastic mutations and symptoms in its victims, affecting them both physically and mentally. These effects are shown to take place in stages.

The first sign of the infection is lethargy in the victim, followed by feelings of sickness and/or pain; the skin turns yellow-green and begins to fester, the eyes water, and mucus begins dripping from the nose. As the infection progresses, the skin starts to sag and detach from the muscles, tearing open holes along the body (particularly the vertebrae). This is followed by rapid and severe dehydration, which then leads to violent, bloody vomiting.

In the victim's final stages of lucidity, small pustules and veins begin appearing on their skin and their eyes undergo a characteristic change; the pupil contracts to the point of invisibility as the rest of the eye becomes red with yellow veins floating around the edges, giving a vague resemblance to a red sphere covered in thick yellow cracks. At this point, the plague has taken complete hold of its victim, inducing a state of violent aggression towards any living creature they see.

### Effects

The disease infects and overtakes the host with astronomical speed. The victims of the plague lose almost all sense of rationality, pain responses, and self-preservation, blindly attacking everyone around them while shrugging off any injuries they receive in the process. They also gain an enhanced degree of tenacity, shown when the Argentinosaurus remained determined to kill Spear and Fang until it was completely incinerated. However, they do not appear to have limitless stamina; the infected sauropod was shown visibly panting after massacring its former herd, and twice entered an apparent state of dormancy when no new victims were in reach.

As the victim succumbs to the plague, its body will gradually begin to assimilate its own internal organs, giving it an emaciated appearance; it is possible that most of the organs are liquefied and expelled from the body during the bloody vomiting prior to fully succumbing. Portions of its skin will begin to corrode and tear away, exposing bone; most notably, the victim's lips will completely dissolve away to expose their teeth.

Individuals exposed to the plague appear to emit an unpleasant, unnatural odor, even if they were not directly infected. This was best seen with the massacred Argentinosaurus herd; Fang recoiled and backed off from a potential meal, while flies and other scavengers avoided the carcasses entirely, even if they had no wounds from the infected sauropod itself (such as the one that had been pushed into a spiked tree). It is unclear if active plague carriers emit similar odors, as none of the beings they encounter show reactions to any stench; however, this may contribute to why Spear and Fang immediately flee from the infected Argentinosaurus.

The plague's very nature is peculiar; it is unclear whether the plague can infect more than one victim at a time given how only one creature was shown to be alive and infected in the episode, as the infected Argentinosaurus left no survivors during its slaughter of its herd-mates after killing the infected hadrosaur that bit it.

Although carriers of the plague can function without most of their vital organs and muscles, they seem to require their central nervous system. The infected Parasaurolophus died when its latest victim kicked it into a tree with enough force to break its spine, and the infected Argentinosaurus only seemed to perish when its head (and whatever was left of its brain) was completely burned away.

## History

The exact nature and origins of the disease itself are ambiguous. The plague is first seen when a Hadrosaur approaches a grazing Argentinosaurus, who, although at first confused by its erratic behavior, ignores it until the infected Hadrosaur bites the sauropod's leg, causing the sauropod to throw it against a tree, killing it.

Moments later, the disease completely takes over the Argentinosaurus and turns the sauropod as well, causing it to begin attacking and brutally slaughtering its entire herd. It later pursues Spear and Fang when they come across the carnage, eventually meeting its end when its weight causes it to become trapped and incinerated in a pool of lava. ("Plague of Madness")

## Trivia

* Whether or not the disease is a real-life microorganism, or a fictional entity is unclear, but the symptoms resemble those of real-life infectious diseases such as rabies and necrotizing fasciitis (a.k.a. Flesh-eating disease).
	+ The disease contains similarities to various other sicknesses from fictional media, including Rage from *28 Days Later* and Cabin Fever from the film of the same name.
	+ Another argument can be made that the plague is a supernatural entity instead of a true disease, due to its rapid takeover, inducing an intense, zombie-esque behavior, and ability to function with grievous injuries, all despite being reduced to the point of being only skin over bone.
* It is implied that the disease's transmission requires a living host, given the victims of the infected Argentinosaurus did not rise under the control of the infection, despite being bitten prior to their deaths. According to the pitch animatic for the episode, the Parasaurolophus's transition from bloodshot to normal eyes upon its death visualizes the animal returning to normal. This implies that if the host dies, the disease "dies" with it, or is at least no longer able to affect them.
* Coincidentally, a similar disease to the plague may have existed in real life during the late cretaceous in Brazil. In October 2020, the bones of a titanosaur related to Argentinosaurus were examined after they showed signs of a severe case of the debilitating bone disease called osteomyelitis, caused by what appear to be prehistoric blood worm parasites. Based on the evidence, the infection contributed to the sauropod's death. These blood worms can and possibly did cause similar symptoms to the flesh-rotting plague in Primal.
* The plague also shares similarities with real-life parasitic fungi that hijack an insect host's nervous system in order to spread to other organisms. The fungus *Eryniopsis lampyridarum* is the most similar, including taking over the host's brain and nervous system alive as the rest of the body rots in order to transport itself to more suitable locations and spread its spores.

## References

1. ↑ "Plague of Madness Pitch Animatic". (Video) *Adult Swim*.
2. ↑ "Blood parasites and acute osteomyelitis in a non-avian dinosaur (Sauropoda, Titanosauria) from the Upper Cretaceous Adamantina Formation, Bauru Basin, Southeast Brazil". *ScienceDirect*. Cretaceous Research.