Once the Ocean's Dominant Predator, Suppressing Sharks for Millions of Years!
Sharks are top predatory animals in the ocean, and they have existed for hundreds of millions of years. Learning about the evolutionary history of sharks reveals that they are the result of years of a wife's diligent efforts in transforming into a mother-in-law. When sharks first appeared on Earth, they were once threatened by other species.
The earliest animals that threatened sharks were the Cambrian fish, known as Dunkleosteus!
Dunkleosteus lived during the Ordovician period from 3.8 million to 3.6 million years ago. There are currently 10 known species, the largest Dunkleosteus measuring 6 meters long and weighing approximately 1 ton. They were once the dominant predators in the ocean, found in almost every corner of the sea.
Dunkleosteus belongs to the group of placoderms. The placoderms were a huge family during the early Paleozoic Era, and they went extinct around 3.6 million years ago during the Late Ordovician period. These fish are characterized by bony plates on their heads and chests, connected to the skin surface with muscles and joints, allowing for great flexibility.
During the Ordovician period, as a cartilaginous fish, sharks began to evolve and take shape. Although they were also very fierce, they were often killed in combat and became food for Dunkleosteus. This is because cartilaginous fish, aside from teeth, have bones composed entirely of cartilage, and they lack armor protection. When fighting with placoderms, they were like a lightly armed infantry challenging a heavily armored samurai.
Dunkleosteus's most formidable feature is its huge mouth, with a biting force of over 5000 pounds. In that era, no animal could withstand such powerful bite strength. In addition, Dunkleosteus's head was covered by a 5-centimeter-thick bony plate, protecting its head during combat.
It also has a flexible head joint, and its mouth can close in 0.2 seconds, making it difficult for prey to escape. The only disadvantage is that it cannot chew food; it can only swallow it whole.
Furthermore, Dunkleosteus's digestive system is not very good, and it cannot digest the bones of its prey, so it will regurgitate the undigested parts instead of excreting them.
Regarding the skin color of Dunkleosteus, recent excavations have found that their skin contains red and white pigment cells, indicating that they also have the ability to perceive color.
The image below shows a reconstruction of Dunkleosteus, with a more diverse color.
Although Dunkleosteus is formidable, its huge body and thick armor limit its flexibility, and it went extinct in the late Ordovician period. Soon, sharks occupied the space left by Dunkleosteus, and after enduring millions of years, sharks finally became the new dominant predators of the ocean.
