00:00A fragment of a whale's rib has recently been discovered in a mine in North Carolina.
00:04This may seem anecdotal.
00:06Why a whale could not be a bottom miner, after all?
00:09However, this piece provides scientists with a rare opportunity
00:13to study the interactions between prehistoric sharks and whales dating from 3 to 4 million years.
00:19This fragment of rib has three teeth marks,
00:21revealing that this whale has been bitten by an animal with extremely powerful jaws.
00:26According to the spacing of the marks, which reaches nearly 6.3 cm,
00:30it is possible that it is a large-toothed shark, such as the megalodon,
00:34or another species of shark that lived at that time.
00:37The curvature of the shark's jaw indicates that the animal was relatively small,
00:42with an estimated size between 4 and 6 meters.
00:45As for the whale, it seems to have been the ancestor of a blue whale, or a bass.
00:49Researchers are amazed.
00:51It is rare to find traces of interaction and animal behavior
00:55so well preserved in fossil form.
00:57After analyzing the sample,
00:59they concluded that this shark had to leave with a consequent bite,
01:03but that the whale had survived.
01:05Because most of the fossil fragment was covered with metaplastic bones.
01:09This bone material quickly forms in response to a localized infection.
01:14It is not particularly robust and is subsequently remodeled by the body into a compact bone tissue,
01:20a process that takes time.
01:22The presence of this bone indicates that the healing was incomplete,
01:25and the whale died 2 to 6 weeks after this unfortunate encounter.
01:29However, it is also possible that its death is not directly related to the infection and the wound.
01:35Only a few fossils testify to such interactions between ancient animals.
01:39There are often bite marks on the fossils,
01:42indicating where the animal died and where its carcass was devoured.
01:46But this vestige is one of the few to illustrate not only an injury inflicted by another animal,
01:51but also to demonstrate that the prey survived.
01:54All fossils arouse the enthusiasm of paleontologists.
01:57And yes, these people may have to leave their homes more often.
02:01But some fossils may seem terrifying to the general public.
02:04Take for example this image showing tentacle arms and octagonal heads.
02:09During its first appearance in the media,
02:11many netizens have advanced that it was an ancient organism from space.
02:17Others have estimated that the whole story was just an imposture.
02:20However, the image is as authentic as the fossil.
02:23This fossil is known as the Plague of Mortality,
02:27a fossilized representation of a massive extinction event affecting one or more species.
02:32In reality, this fossil contains more than a dozen specimens of a type of marine organism called crinoids.
02:38Contrary to their appearance, crinoids were not plants but marine animals.
02:43This particular species lived deeply underwater, on the ocean floor.
02:47The crinoids were related to sea stars, bears and dolphins.
02:52These creatures could anchor themselves to the seabed
02:54thanks to rods made of flexible and porous discs connected by soft fabrics.
02:59These rods were hollow and sheltered the nervous system of the animal.
03:03The crinoids absorbed oxygen through tubular feet on thin walls.
03:08Generally, these animals were more than 20 cm long
03:12and had five arms decorated with structures similar to feathered tentacles.
03:16They fed on plankton and organic matter when drifting.
03:19Although these fossil discoveries are quite fascinating,
03:23few creatures whose fossils we have
03:25have intrigued scientists as much as the monster of Thule.
03:28This strange marine creature had a toothed muzzle resembling a trunk
03:33and eyes spread out along a rigid stem.
03:36But the strangest thing is that it remains impossible to classify.
03:39Since the discovery of the monster in 1966,
03:43researchers have considered various hypotheses concerning its identity,
03:47such as segmented worms, swimming lemmas,
03:50or primitive creatures resembling eels.
03:53More recently, some have tried to link it to species of fish without jaws
03:58and with a structure similar to a spine.
04:02A team of Japanese scientists used high-resolution laser scanners
04:06to analyze in three dimensions the anatomy of the Thule monster fossils.
04:10They concluded that this enigmatic fossil could ultimately be that of an invertebrate.
04:15However, the true identity of this creature is still undetermined.
04:20In the 1950s, an amateur fossil hunter named Francis Thule
04:25discovered the strange footprint of a torpedo-shaped organism
04:28with a huge caudal jaw in the fossil deposits of Mason Creek, Illinois.
04:33Having never observed a similar creature,
04:36Thule brought his discovery to the Chicago Museum of Natural History.
04:40The institute's paleontologists were also disconcerted.
04:43Since then, scientists have still failed to locate this creature on the phylogenetic tree.
04:50In 1741, explorer and captain Vitus Jonas Bering
04:54led an expedition to map the Alaska coast.
04:58The ship he was on sank on what became the island of Bering.
05:03Half of the crew survived thanks to the discovery of a huge sea cow,
05:08or Hydrodamalis gigas.
05:10With the meat of these animals to give them strength,
05:13the sailors managed to build a small raft from debris and return home.
05:18During the return trip,
05:20a scientist in the crew devoted his time to documenting the animals and discovery plans.
05:25The sea cow was particularly remarkable because without it, the crew would not have survived.
05:31These animals were more than 8 meters long and weighed about 10 tons.
05:34All sea cows belonged to the order of the Sirenias,
05:37sea mammals closer to elephants than cows.
05:41The scientist described them as having black skin, a small head and ragged anterior limbs.
05:46These sea cows floated on the surface of the water feeding on algae.
05:49Once the existence of these animals was made public,
05:52fur trade expeditions began to exploit this very practical depot on the way.
05:57The sea cows, being very docile and easy to hunt,
06:01were exterminated barely 27 years after the scientist had spoken of them.
06:05However, this is not the saddest part.
06:08Fossil archives reveal a much darker story.
06:11Fossils have thus been found around the world, from Japan to Mexico.
06:16This indicates that these animals once prospered in the vast fields of Varek,
06:20which surrounded the entire North Pacific Basin.
06:23The reduced population discovered by the expedition
06:26was probably the last remains of a much larger population and in much better health.
06:31It is highly likely that the hunting practiced by aboriginal populations
06:34had already reduced the number of these animals to a level close to extinction.
06:38The fatal blow was carried out by Western hunters.
06:42Today, the close relatives still alive of these ancient sea cows are rarely hunted.
06:47But they themselves are threatened with extinction.
06:50For some, this amazing fossil may seem somewhat disturbing.
06:53Numulites are the fossil of animals whose name means small piece in Latin.
06:59These creatures lived and prospered in a warm and shallow sea
07:03that covered part of Egypt about 40 million years ago.
07:08The name Numulites suggests that the largest specimens
07:12were particularly popular throughout history.
07:15And in Egyptian folklore, they are even nicknamed the Angels' Coins.
07:19These creatures have a simple and unicellular structure
07:23that contrasts with their extremely complex skeletons.
07:26Observe this series of superimposed spirals.
07:29Each spiral is divided into innumerable tiny chambers
07:33and Numulites can reach up to 10 cm in diameter.
07:37However, they are fossils of unicellular animals related to amoebas.
07:41So how could they reach such a size?
07:44The reason could be in their symbiotic relationship with other smaller organisms.
07:49For modern species, these symbiotes are golden unicellular algae called diatomaceae.
07:55The shells of Numulites being relatively transparent and flat,
07:58they offer a large surface for the light necessary for the photosynthesis of diatomaceae.
08:03For reasons still debated by scientists,
08:05the presence of plant symbiotes in marine animals
08:08favors the growth of a limestone skeleton in others.
08:11Thus, the colossal size of Numulites in Egypt
08:14could be attributed to their close relationship with symbiotic diatomaceae.
08:18Does this seem plausible to you?
08:20Interestingly, Numulite species have evolved very quickly
08:24and their fossils have altered from one layer of sediment to the other.
08:27Thus, the limestone used for the pyramids of Giza
08:31is so rich in these fossils that it is designated under the name of Numulitic limestone.
08:35This limestone also contains two types of Numulite,
08:38the small lenses of slaves and the large coins of angels.
08:42However, these are not different species,
08:45but rather different stages of the life cycle of the same creature.
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