Within a few million years, the old miraculous dolphins slid through the seas, which were in many respects similar to today's toothed whales, emphasizing extreme long innings. These odd bastards had relatively longer blondes than any other water mammal or reptile that lives or is extinct; some nose-like supplements have prolonged more than 500 percent longer than their brain. Even Matthew McCurry, a curator of palaeontology in the Australian Museum, who studied the evolution of long insects in the predominant species, notes that their skulls are "very strange".
In 2015, McCurry, as the predecessor in the Smithsonian's Natural History Museum, decided to look more closely at these extinct marine mammals. Scientists have known them for over 100 years, but nobody left the function of their rich insects. The hypotheses were "to a great extent high-quality and restless", says Nicholas Pyenson, curator of fossil marine mammals at the Natural History Museum. "People said," Oh, a long moss is probably used to mix the prey in the sediment … [W]I would say that the hat would be an adjustment hypothesis, but nothing really was tested. "
So McCurry and Pyenson did exactly that. And in the new paper published in Paleobiology, the researchers uncovered an unusual example of a dolphin dolphin: the creatures that they found could flood the avalanches with water in order to hit and stun prey, as much as the swordfish today.
In their efforts to analyze the unique skulls of long-standing Chinese, McCurry and Pyenson turned to Smithsonian's huge source of whale fossils. "We have so many people who have not been studied that I can not really tell the whole range of fossil whale records we have," says Pyenson, but estimates that there are as many as 15,000 in the collection.
The researchers performed a computer tomography (CT) scanning the quarry of the three extinct species (Pomatodelphis inaequalis, Xiphiacetus bossi in Zarhachis flagellator) and castings of two other ancient whales (Parapontoporia sternbergi in Zarhinocetus errabundus). To compare these creatures to the animals that were inhabited today, McCurry and Pyenson examined two species of river dolphins, which have considerably longer fins than their oceanic settlements, although not nearly as long as their prehistoric precursors. The researchers also studied two species of long fish that they named: blue Atlantic blue and swordfish.
McCurry and Pyenson then analyzed the digital skull models using the calculations relied on by engineers to evaluate the carrying capacity of the rays. According to Pyenson, "beam theory" is useful in the study of the insect because "it talks about these objects, as they are built to respond to forces: how rigid it is, what tensions are applied." And the researchers found that the dolphins of the former general would have no difficulty in moving their impressive sponges through the water to destroy their prey.
Because the types of puppies have changed into shape, they have moved their handy accessories in different ways. Some were pulled from one side to the other, the other up and down, and others were able to move the nose in several directions.
"Imagine a ray like a skis," says Pyenson as an example. "Ski bends well up and down, but not on the side. The pole, which has the same shape, can bend up and down [and] from side to side, there is no problem. "
The researchers were particularly affected by the fact that these animals were not closely related to each other. It seems that some species have independently developed extremely long insects, indicating that something in their environment was accompanied by a change. But what, exactly?
Long-term dolphins appeared in the Middle Miocene, a ranging from 11.6 to 16 million years ago, when the climate was warmer than it is today. The ocean temperature has risen and the sea level has increased and created more seabed along the sea, which is "a really big habitat for fish and other dolphin diapers," says Pyenson. But the response of an emergency fish becomes faster in warmer waters, making it harder to catch. Researchers can theorize that dolphins developed hyper long insects in this period to give them an added advantage during hunting.
For millions of years, the global temperature remained stable, and dolphins were cut into warm water with extremely elongated avalanches.
"Maybe this is the result of what happens if you have such an environment stable for millions of years," Pyenson teaches. "These properties are exaggerated."
But with the advent of Pliocene, the climate has become more irregular and the abundance of moderate coastal areas on the shores fluctuates. With these changes, dolphin dolphins disappeared. And this raises interesting questions about whether the evolutionary move of the extinct dolphins can tell us something about how dolphins may come in the current era of climate change.
The story of these ancient beings highlights how the environment of an organism changes its appearance and clearly shows what we lose in terms of biodiversity when changing the environment, the zoologist Karina Amaral from the federal university in Rio Grande do Sulu, who did not participate in the study, tells Ed Yong from Atlantic. And this is important to take into account, in particular, "[at] a time when many insist on ignoring our changing climate, "says Amaral.
What can the evolutionary action of the extinct dolphins tell us about how dolphins may come in the current era of climate change? McCurry concludes that it is difficult to draw definitive conclusions because today temperature fluctuations are "unprecedented in their causes and speeds." However, he sees the study as a "warning story", and Pyenson adds that they can look more closely at ancient whales. An insight into the future of the Earth's ocean systems.
"High levels of sea level, acidified oceans, warmer oceans – these are all properties of past whales," he says. "Looking at the fossil record that looks at the biological response of these past worlds, this will really be a major advance."