Young Science Student Brian Dahlberg of Hillsborough County Discovers Missing Link

Brian Dahlberg, a young science student and 'fossil hunter' from Hillsborough County, FL, has been involved in what can be considered as a major discovery. A 36 million year old fossil was found in Peru, belonging to the Mystacodon selenensis. This prehistoric animal is the closest cousin to the modern baleen whale. According to Brian Dahlberg, it is also a key missing link, providing fantastic insights from an evolutionary perspective.

Brian Dahlberg says: "When we found the fossil and I started studying it, I was amazed. This truly is the missing link we have been looking for in terms of how baleen whales have evolved after millions of years. That 36 million year old fossil is providing a wealth of knowledge in evolution!"

The fossil belongs to the family of mysticeti. What was uncovered was a large number of baleens, which are plates shaped almost like a sieve. These baleens are used to filter water, while leaving food behind. The family of mysticeti includes the humpback whale, the gray whale, and the enormous blue whale. It has long been known that baleen whales and toothed whales had a common ancestor. The toothed whale is the second family of whales that still exists today. What hasn't been known, however, is why some whales kept the baleen, whereas others developed teeth. The uncovered fossil is now believed to be the oldest cousin of both, potentially showing exactly how this evolution took place.

"Around 39 million years ago, the mysteciti family split into two," adds Brian Dahlberg. "The fossil we have discovered is some 36.4 million years old, meaning it is only around three million years younger than the mysticeti that is the common ancestor. In terms of evolution, that is just a blink of an eye."

The fossil was found at Playa Media Luna, in Peru. The paleontologists who found it named it 'Mystacodon selenensis', which is a combination of the Greek words for 'tooth' and 'mustache'. Additionally, there is a slight reference to the Greek moon goddess in there as well. The question for Brian Dahlberg, however, was how the whale evolved into having a 'mustache' in the first place.

"From the remains, we can see that the animal was around four meters long," he adds. "However, it didn't have baleen but rather vestigial hind limbs and a mouthful of teeth. When I analyzed the skull, teeth, and jaw, I came to the conclusion that the whale basically sucked up other marine creatures, lowering the pressure in its mouth with its tongue, expelling the water once it had its prey."

He adds: "If I am right, then it stands to reason that its prey was quite small, since it had to be swallowed whole. So this would mean small squid and medium fish." What makes this discovery so interesting is that both toothed and baleen whales, in the past, grabbed prey with their teeth. Today, only toothed whales do this."

The body form and presumed feeding method of the discovered whale shows that scientists have been right about their expectations in terms of the features an animal would have to be the predecessor of the modern whale. This information has gathered a lot of interest, not in the least because it has confirmed these predictions.

At the same time, Brian Dahlberg found some really big surprises. "The creature actually had hind limbs, which must have been pretty much useless! They stick out from the body. We really didn't see this coming. No modern whale has hind limbs and since fossils have all shown vestigial limbs, we always believed that the common ancestor of the baleen and toothed whales didn't have hind limbs anymore. Clearly, we were wrong."

It seems, therefore, that both the toothed whale and the baleen whale evolved further and, independently of each other, and then lost the hind limbs. While this is incredibly interesting, the suction feeding element is what has really gotten other scientists interested. In fact, paleobiologists from Tampa have contacted Brian Dahlberg to ask if they could become involved in future research. The fossil is an opportunity for them to learn more about evolution, and about the whale family. Particularly, they aim to find out whether recent theories are true, which focus on terrestrial animals going back into the water, which eventually created the whale we know today.

Brian Dahlberg ends: "This fossil is really interesting, and I'm happy to see that other scientists in the Tampa are also wondering just like me whether the whale was once a terrestrial animal. I can't wait to see what else we will uncover in terms of their evolution and feeding habits."

Source: Brian Dahlberg