Dinosaurs Max's Random Ramblings

Venomous Dinosaurs: Fact or Fiction?

Jurassic Park introduced the world to Dilophosaurus, a predatory dinosaur that could spit venom. But was it capable of this? And have any other dinosaurs been revealed as venomous?

If you really think about it, Jurassic Park is a horror movie. I will stand by that statement so long as I breathe. This is clearly presented through the venom spitting Dilophosaurus.

At the start of the film’s second act, the villainous Dennis Nedry tries to flee Jurassic Park after sabotaging the island’s protection systems. Unfortunately for Nedry, he stumbles into the enclosure of Dilophosaurus. Dilophosaurus is portrayed as wolf sized and in possession of an interesting physiological mechanism: the ability to shoot venom. For poor Nedry, this means a viscous and gruesome end. This does however raise a question: was Dilophosaurus, or any other dinosaur, venomous?

Jurassic Park Dilophosaurus

Let’s start with Dilophosaurus. As many people are aware, Jurassic Parks’ depictions of dinosaurs are often inaccurate. Dilophosaurus was no exception. The real Dilophosaurus was almost triple the size, had a very different frill ornamentation, and unfortunately, didn’t spit venom. The structure of their teeth and jaws show no indication of any glands where venom may have been stored or ejected, so a venomous Dilophosaurus would have been impossible. Like most predatory dinosaurs, it’s teeth would have made for formidable weapons, thus neglecting the need for a venomous bite.

The Potentially Poisonous Raptor

The skull and proposed fangs of Sinornithosaurus

In 2009, a controversial paper hypothesized that Sinornithosaurus, a small dromaeosaurid from Cretaceous China, was venomous. The paper cited three anatomical features as evidence of venom production. The first feature was elongated teeth of the upper jaw, which were deemed similar in length and shape to the fangs of modern venomous animals such as snakes. Second, the teeth of Sinornithosaurus possessed grooves alongside the edges that were interpreted to be venom channels. Lastly, a hollow cavity within the upper jaw seemed to be the perfect place to store venom. Seems conclusive, right?

Unfortunately, most paleontologists did not see it this way. Instead of seeing specialized adaptations associated with venom production, they saw basic features of raptor dinosaurs. The elongated teeth that were perfect for delivering venom? Turns out they slipped out of the jaw socket after death and were normal length for raptors. The venom grooves along the teeth were unlike any other venomous animal and don’t differ from other dinosaurs enough to justify them being venomous. Lastly, the venom cavity wasn’t a unique characteristic to Sinornithosaurus as most raptors had similar structures in the upper jaw. While some still maintain hope that Sinornithosaurus may have been venomous, due in part to its appearance on the 2012 documentary Planet Dinosaur, it seems highly unlikely that this was the case.

Toxins…of a Different Kind.

It has been theorized that large carnivorous dinosaurs possessed a septic bite. In this theory, the bacteria transferred from the predators’ bite would induce septicemia, a blood infection that poisons the blood and often leads to death. The notion of septic bites originates from the Komodo Dragon, a reptile that hunts comparatively large prey like deer and Water Buffalo due to its infamous bite. The likely candidates for this adaptation were the Allosaurids, as members of this family hunted giant sauropods the size of whales.

Komodo Dragon

There is one problem with this theory, however: the Komodo Dragon doesn’t have a septic bite. Recent studies have unveiled that the Komodo Dragon is in fact venomous and doesn’t kill prey through infection. At present, no other animal is theorized to have a septic bite. So, could theropods like Allosaurus and kin had such an adaptation? It’s possible. Having said this, possessing a mouth teeming with deadly bacteria would be dangerous, right? Bacteria doesn’t differentiate predator and prey, meaning that the sepsis meant for prey could just spread to the predator itself. Or maybe just cause a bad cavity.

Where does all this leave us? It seems unlikely that a venomous dinosaur will be discovered, as no bird species in the present is venomous. There are two things I should note, however. First, though birds are the descendants of dinosaurs, this does not mean that it would be impossible to find a venomous dinosaur; just unlikely. As the technology used in paleontology advances and new, complex specimens continue to be discovered, finding a venomous dinosaur may be in the cards. The second thing is that while there are no venomous birds, there are poisonous birds. These birds consume toxic food that in turn makes them toxic to predators, an effective form of defense. While it would be almost impossible to prove this adaptation in a dinosaur, it’s always fun to speculate.


I do not take credit for any images found in this article.

Dilophosaurus courtesy of Universal Picture’s Jurassic Park

Sinornithosaurus found here

Komodo Dragon found here

“10 Top Poisonous Birds: Toxic Birds: Birds Adaptations: Bioexplorer.” Bio Explorer, 13 June 2021,

Barry, Carolyn. “Research Finds That Komodo Dragons Kill with Venom.” Animals, National Geographic, 3 May 2021,,and%20ultimately%20kill%20their%20prey.&text=Komodo%20dragons%20kill%20using%20a,confirmed%20for%20the%20first%20time.

Black, Riley. “Sinornithosaurus Probably Wasn’t Venomous after All.”, Smithsonian Institution, 9 July 2010,

Madrigal, Alexis. “T. Rex Bite Marks Actually Festering Infections.” Wired, Conde Nast, 29 Sept. 2009,,Rex%20Bite%20Marks%20Actually%20Festering%20Infections,off%20Sue%2C%20the%20famous%20T.

Pickrell, John. “’Jurassic Park’ Got Almost Everything Wrong about This Iconic Dinosaur.” Science, National Geographic, 3 May 2021,

One reply on “Venomous Dinosaurs: Fact or Fiction?”

As far as I understand, Humans have a septic bite, kind of. At least it’s dangerous to other humans.

Our mouth is full of bacteria. As long as they stay in the mouth cavity and don’t enter the blood stream, it’s fine, we are protected by our mucosa. But an untreated human bite can be worse than a dog bite since it can lead to sepsis caused by some of the more unusual bacteria. Cat bites can be similarly dangerous to humans.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s