introduction:
We all know that whales are mammals that live in the ocean, but mammals mostly live on land, so how did whales get into the ocean?
How did the whales in the ocean evolve now?
<h1>Bucky Whale Origin</h1>
In fact, people did not know that whales were mammals until the 18th century, and it was not until the 19th century that people began to understand whales and guess how whales are produced, which is a profound question. At the time, Darwin, the founder of evolution, believed that "the whale's close relatives may be some kind of bear, and the theoretical basis is that black bears can swim in the water for a long time, as long as the environment is suitable, then this possibility is completely existent." And wrote this theoretical view into The Origin of Species. Obviously, this was just Darwin's old man's speculation, or an example of evolutionary theory, but at that time people took it out of context as " Bears are the direct ancestors of whales !" And caused ridicule from all walks of life, and finally Darwin had to delete this passage. However, his view is not all wrong, at least, whales are a class of land mammals that slowly evolved after entering the ocean.
Darwin said: "I'm just making an analogy
With the excavation and study of fossils by paleontologists, there are constantly the discovery of early whale fossils, such as dragon king whales, spear-toothed whales, proto whales, etc., but these whales have evolved into complete marine animals, until the 1970s, people found some tetrapod fossils in India and Pakistan, Philip Kinggridge's bone study of fossils found that this animal is related to whales, which is the protagonist we are going to introduce today - Bucky whale.
<h1>From land to sea</h1>
Bucky whale genus (scientific name: Pakicetus), is an extinct ancient whale, mainly living on land, belongs to the order Bucky whale family, is the predecessor of modern whales, first found in Pakistan, so also known as Pakistani whale. Bucky whale, which lived in the Eocene (52-48 million years ago), needed to hunt in shallow waters, so its fossils are mainly distributed in the coastal part of the Tethys Ocean.
Bucky whale fossils
Bucky whales retain most of the characteristics of land mammals, with a wolf-like body shape, a long conical head, four feet on the ground, a slender tail, and hairs all over the body. The position of their ear bones, the folding of the middle ear, and the arrangement of the small teeth on the molars are similar to those of today's whales. As a result, it is considered a transitional species of extinct land mammals and modern whales.
Although whales, they do not possess the necessary characteristics of aquatic life, so they can only live on land on the shores of shallow seas or large lakes, preying on small animals, fish and some plants.
Bucky whale restoration
Speaking of this, you may have doubts, obviously it is a mammal living on land, but it is going to the sea to hunt prey, and there must be something strange in it. Yes, not forced by life, who wants to leave home. Like bucky whales, they were a type of ancient ungulate, and their development at that time was far less mature than that of the odd-hoofed beasts, and their access to food was very limited. This, combined with the shortage of food caused by environmental changes, has forced them to find food in the shallow sea.
Bucky whale swimming looks more like a "dog planer"
Since then, such ancient beasts have begun to expand their ecological niche in the ocean as if they had discovered a new continent, and slowly some of them began to evolve organs that could adapt to life in the water, such as the wandering whale with a strong tail and long slurry-like hind limbs. Wandering whales, which are cetaceans that have further adapted to the ocean, are about 3 meters long, with a large head, a long snout, and eyes located on the dorsal side of the head. Studies have shown that wandering whales live in shallow seas and are able to drink seawater like modern whales.
Wandering whales swim a lot more powerfully than Bucky whales
In this way, with the continuous excavation and research of fossils, Paleontologists have put together a complete route of whale evolution: Pakicetid - Ambulocetus - Protocetid - Rodhocetus - Basilosaurus - Dorudontid - Aetiocetus - Squalodon - Cetotherium - Manatee Whale (Odobenocetops) - Modern Baleen Whale and Modern Tooth Whale 。
Diagram of the main evolutionary evolution of cetaceans
Now scientists, through the study of genetic sequences, also prove that whales and hippopotamus are the closest relatives in extant animals, and they have a common ancestor more than 50 million years ago; followed by other even-hoofed animals such as ruminants, pigs, and camels.