'Alien' Fish From 360 Million Years Ago Could Have Had One of the Most Extreme Underbite With Its Extremely Elongated Lower Jaw, Study Finds

Scientists think that the ancient fossilized fish could have been one of nature's top contenders for having the most extreme underbite.

Alien Fish With Extreme Underbite

The first known fossil of this ancient fish was unearthed in Poland back in 1957. The researcher who discovered the fish thought that the creature had a long fin spine set, which inspired the alien name of Alienacanthus.

However, new analysis shows that these spines were actually an incredible, long lower jaw filled with teeth. This makes this feature one of the longest and oldest recorded underbites. This was noted in the "Extreme lower jaw elongation in a placoderm reflects high disparity and modularity in early vertebrate evolution" study.

Melina Jobbins, a paleontologist from the University of Zurich and the study's lead author, explains that the new findings regarding Alienacanthus set the record straight regarding the appearance of this creature. Rather than having an odd spine, it actually has a distinct lower jaw.

The creature lived back in the Devonian period, roughly 358.9 to 419 million years ago. Since its initial discovery, several other specimens of the fossil have been spotted in the mountains of present-day Morocco and Poland. The fish's presence across the two ends of the supercontinent suggests that the fish moved through the ocean despite fluctuations in sea levels.

To learn more about the alien fish, the researchers examined two nearly-complete skulls that were found in Morocco's Anti-Atlas mountain range. They soon found that the elongated protrusion was the fish's lower jaw. Interestingly, this lower jaw was twice the size of its skull.

While the fish is a placoderm, which is an armored fish group that includes some of the first vertebrates with daws, the fish's upper jaws were able to move a tad bit independently of its skull. This helped it accommodate its elongated jaw. Jobbins explains that the creature was so unique that its whole jaw mechanism needed to work differently in order to accommodate its lower jaw.

Underbite Function

To know how these creatures could have maximized their underbite, the researcher compared it with modern-day species that have jaws that are mismatched, including swordfish. They were able to come up with three primary hypotheses to determine how the creatures may have maximized this underbite. These theories are to confuse or injure prey, to trap living prey, or to sieve through the ocean basin's sediments.

Jobbins explains that the hypothesis pertaining to trapping living prey is the most compelling explanation, as it is based on its teeth. Jobbins adds that the teeth pointing to the back stop the prey from leaving the mouth once it gets trapped.

Now that this underbite feature has been cleared up, the experts are studying the fish further to know more about the mechanics of its jaw and the appearance of the rest of its body.

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