PULAKRANJAN Chakraborty
Once upon a time, gigantic dinosaurs roamed the earth. Scientists believe that about 230 million years ago, during the Triassic period, these reptiles lived on a single supercontinent called Pangaea.
During the 165 million years that dinosaurs existed, this supercontinent gradually broke apart, giving rise to several continents. As Pangaea split and new continents formed, dinosaurs spread to different regions of the world.
It is believed that about sixty-five million years ago, they all died out as a result of a catastrophic event. Today, dinosaurs exist only through their fossils.
Researchers say that a massive asteroid struck the Earth, causing a tremendous explosion and major environmental changes. These changes wiped out the dinosaurs from the planet. However, scientists from the University of Reading in the United Kingdom, after analyzing dinosaur fossils, claim that the extinction process had actually begun long before the asteroid impact, the asteroid only marked its end. They believe that dinosaurs began to die out because they could not adapt to the changing Earth, and that this extinction process started around 1.2 million years earlier.
From the fossils of these colossal creatures scattered across the globe, scientists have gathered various pieces of information over time. The search for knowledge about dinosaurs continues, as does the excavation of their fossils.
Recently, scientists discovered a fossil of a two-headed dinosaur that is more than 120 million years old. This dinosaur, named Hyphalosaurus, did not have a long neck like many others, but it was quite large in size. The Hyphalosaurus lived during the early Cretaceous period of the prehistoric era. It was a carnivorous and powerful creature, agile enough to catch small prey.
In the history of dinosaurs, the Cretaceous period was the longest, lasting from about 145 million years ago until roughly 65 million years ago.
Since the fossil sample shows signs of two heads, scientists have identified it as a rare developmental anomaly. Such a condition occurs when the process of embryo division into twins fails, resulting in a creature with two heads. It is believed that this dinosaur was born in a similar way.
The fossil was discovered in the Yixian Formation region of northeastern China. After detailed analysis, scientists reported that although two-headed reptiles like snakes, lizards, and turtles can still be found today, no such defect had ever been found in ancient species. Therefore, this fossil is considered the oldest example of a vertebrate with such a deformity. The discovery has opened new avenues for studying the biology and evolution of early reptiles.
When the animal’s spinal column began to divide longitudinally, an error caused two parallel necks to form, leading to the development of two separate skulls. This was an incomplete twin process, where a genetic defect caused the formation of connected heads. Such abnormalities are extremely rare among reptiles and other vertebrates. The two-headed Hyphalosaurus fossil, measuring about 70 millimeters in length, is believed to have been that of a newborn dinosaur which did not survive long after hatching. Due to its short lifespan, many developmental details are missing in the fossil. Still, scientists believe that this ancient evidence of a congenital defect will provide valuable new insights.
Eric Buffetaut, lead researcher at the National Center for Scientific Research in Paris, said, “This is a discovery you could never have imagined before. The chances of such an unusual fossil surviving are extremely low.”
The discovery of this fossil has given scientists a new opportunity to learn about the biological traits and evolutionary history of ancient reptiles.