4 This fossil shows the unique tooth whorl of Helicoprion, a distant relative of modern sharks. Now extinct, this genus of holocephalid eugeneodontid fish had a buzz saw mouth.

Helicoprion, a prehistoric and extinct species of fish, is the only animal to ever exist with a buzz saw like tooth whorl. Thought to be the distant relative of modern sharks, the Helicoprion lived some 270 million years in the past. It grew up to 25-feet long and was native to the oceans that covered present-day eastern Idaho.

The most striking feature of this species was, of course, it’s lower jaw that was covered in the oddest of teeth formations ever seen in the animal kingdom. Experts say that when attacking its prey, the fish would rotate its sharp tooth whorl backward almost like a buzz saw. It would slash through the prey in a deadly motion.

This particular fossil was uncovered during operations at Soda Springs mines, owned by American agrochemical company, Mosanto. However, Helicoprion fossils have a long history. Alexander Petrovich Karpinsky, a Russian geologist came up with the name in 1899. Even though he realized that the coiled fossil was part of a shark-like fish, he was not certain about where it fit or how it was used.

The breakthrough came in 1950, when Svend Erik Bendix-Almgreen, a Danish palaeontologist, discovered Helicoprion whorl in Idaho’s Waterloo Mine. The fossil was called IMNH 37899 and donated to the Idaho Museum of Natural History. While describing the fossil in 1966, 16 years after it was first discovered, Bendix-Almgreen revealed that 117 visible serrated teeth sit on a 23cm spiral. The fossil also showed some cranial cartilage, proving for the very first time that the specimen came from the Helicoprion’s mouth.

After conducting a careful analysis of the fossil, scientists determined that the tooth whorl served two main functions. The outermost part would act as an anchor when biting. The inner spiral would house the previously used, old teeth from when the fish was younger. The fossil did not bear any signs of wear and tear. That confirmed that the fish mainly hunted soft and chewy marine creatures like squid. (1, 2, 3)

5 Approximately 4,000 fossil specimens have been uncovered in the ancient “Texas Serengeti.” The diverse collection is comprised of over 50 animal species including alligators, rhinos, elephant-like mammals, and more that are said to have existed in the Texas Gulf Coast some 11 to 12 million years back.

During the 1929 Great Depression, a few unemployed Texans found work as fossil hunters, and they were able to discover thousands of fossil specimens. These prehistoric remnants have been kept and studied at the University of Texas for the last 80 years. After spending decades carefully examining these fossils, researchers have identified a large collection to be from the dig sites close to Beeville. The diverse collection of fauna led them to dub the area as the “Texas Serengeti.”

The extensive collection includes fossilized remains of over 50 animal species including several different types of carnivores, 12 species of horses, camels, antelopes, alligators, rhinos, and elephant-like mammals. The elephant-like animal is said to be an extinct relative of modern elephants, and its lower jaw also resembled a shovel. Researchers have identified it as a new gomphothere genus. The discovery has helped scientists to put together a picture of the ecosystem of ancient Texas.

Though astounding, the fossil collection does not fully represent the biodiversity of the Texas Coastal Plains. These were excavated by amateur fossil hunters who did not have the necessary training in paleontology. That is why most of the specimens are of large mammals since big bones, large skulls, teeth, and tusks are more easily spotted, and they are also more exciting. The fossils of the smaller species may have been left behind. (1, 2)

6 This half-billion-year old fossil discovered in China shows the intricate brain structures of a strange sea creature that was once one of the top predators.

The near-perfect fossilized remains of a strange group of sea creatures were uncovered in China. Named Lyrarapax unguispinusis, the ancient creature existed over half a billion years ago in the Cambrian Period. This time period is most notable for being a pivotal juncture when many of the major animal groups were first said to have appeared, setting the course for Earth’s evolutionary history of life. The fossil shows the complex brain structures in minute details, helping researchers to understand more about this life form.

The creature was part of a group called anomalocaridids which were the primitive ancestors of arthropods including spiders, insects, and crustaceans. They are famous for hunting prey with two claw-like appendages located in front of their eyes. All forms of anomalocaridids have gone extinct, and they do not have any direct descendants. However, the fossilized brain structure has revealed similarities with Onychophora, commonly known as “velvet worm.”

Upon carefully studying the fossil, researchers have concluded that the velvet worm may be a distant cousin of this ancient creature that lived over 520 million years in the past. The scientific name, Lyrarapax, refers to these lyre-shaped, spiny-clawed predators. It was said to be small, only measuring up to 15 centimeters long. A fully preserved Anomalocaridids, especially one with the brain structure still intact, is a rare find. That is why this fossil is so unique and special. (1, 2)

7 Megalosaurus bucklandii, also dubbed as the first-named dinosaur, is yet to be fully understood. This 200-year-old, lower-jaw fossil of this species is one of the oldest and most crucial discoveries that continues to baffle scientists.

Megalosaurus bucklandii is the very first scientifically described species of dinosaur in the world. The carnivore roamed the Earth approximately 167 million years ago, sometime during the Middle Jurassic period. Known as the top predator in its habitat, the Megalosaurus bucklandii grew up to be 30-feet-tall and weighed around 1,400 kg.

This world-famous fossil of the Megalosaurus jawbone was discovered more than 200 years ago. Excavated from a quarry near Stonesfield, Oxfordshire, the fossil now rests at the Oxford University Museum of Natural History. The most remarkable thing about this fossil is that despite being over two centuries old, it continues to reveal fascinating secrets about this ancient beast.

Mark Williams, a professor of the Warwick University, along with other researchers in the field have recently used specialized 3D analysis software and XCT (X-Ray Computed Tomography) to capture over 3,000 images of the jawbone. These x-ray images helped them to create a 3D version which allowed them to see inside of the jawbone for the first time.

Upon examining and analyzing, they were able to trace the roots of the Megalosaurus’ teeth along with the degree of the various repairs that have taken place over the years. Being as old as it is, the fossil has suffered some damage, possibly from when it was extracted from the rocks.
The XCT images have also revealed teeth that were previously unnoticed. The new teeth were found deep inside the jaw, which means the teeth were still growing when the animal died. The remnants of old, decayed teeth were also found alongside the newly growing ones. Scientists are hopeful that the fossil will continue to tell us more about the Megalosaurus bucklandii. (1, 2)