Falcatus | 3D Dinopedia

Falcatus

Period of life:

324 million years ago

Period:

Carboniferous period

Habitat:

Marine environment

Taxonomy:

Sharks and rays

Height:

0.08 m

Countries:

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Carboniferous period Falcatus | 3D Dinopedia

Falcatus (324 million years ago)

Meaning of the name: Falcatus comes from Latin, meaning “armed with sickles.”

Falcatus was a remarkable cartilaginous fish that lived about 324 million years ago, during the late Carboniferous period, in what is now Montana, USA. This small predator, only 25–30 centimeters long, was a distant relative of modern sharks, but it stood out for one truly unusual feature — a long, curved spine protruding from its back.

The body of Falcatus had a streamlined, torpedo-like shape, making it a fast and agile swimmer. This design reduced water resistance, allowing it to dart quickly after prey or evade larger predators. Its tail fin was forked — a typical heterocercal tail where the upper lobe is larger and supported by the spine. This provided extra lift and allowed Falcatus to maneuver with ease.

The fish had pairs of pectoral and pelvic fins that helped it maintain balance and perform precise movements. Its head was relatively large, with big eyes — a sign that it could see well even in dim light. Its teeth, with multiple sharp points (known as cladodont teeth), were perfectly suited for tearing the flesh of small animals.

But the most mysterious part of Falcatus’ anatomy was its long, curved dorsal spine. Smooth and sharp, it likely served an important biological function. Scientists still debate its purpose. One hypothesis suggests that the spine helped males hold onto females during mating — similar to how modern sharks use specialized organs on their fins, called pterygopodia.

In all respects, Falcatus appears to have been an active and swift predator, well adapted to life in the ancient seas. Its unusual dorsal spine may have served not only for reproduction but also for defense or display. Whatever its purpose, Falcatus remains one of the most intriguing examples of evolutionary experimentation in the prehistoric oceans.

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