Many people fear sharks for their huge sharp teeth, powerful “knives” that became popular from the movies, giving these fish a bad reputation, as if they were fearsome man-eating monsters.
However, what few know is that it is actually not entirely true. Even today, sharks don’t have a particular fixation on including humans in their diet, and they haven’t always had those sharp teeth.
And as strange as it sounds, millions of years ago there were also sharks with flat teeth. Its fossil traces were even found by scientists in African and European countries, and now, for the first time, there is a confirmed record in Colombia, in the municipality of Zapatoca, in Santander, by paleontologists Edwin Cadena, from the Faculty of Natural Sciences from the Universidad del Rosario, and Jorge Carrillo, from the University of Zurich, in Switzerland.
“During the almost 400 million years of evolution of sharks on planet Earth, there have been forms that for many would be unthinkable, including species with completely flat teeth, similar to small dominoes that were used to crush the food, rather than to cut and tear, as in the case of the sharp teeth of most living sharks, ”said Cadena.
Now, what is relevant about this fossil species is that “it constitutes the first record of a family of extinct flat-toothed sharks in the entire American continent,” highlighted the Colombian paleontologist, explaining that this new species has been baptized Strophodus rebecae.
“This species of fossil shark inhabited part of the sea that covered what is now Colombia approximately 135 million years ago, during the geological period known as the early Cretaceous,” said the researcher.
His description was made thanks to the many teeth that Cadena had collected over the years during his fieldwork in Zapatoca. Once he and Carrillo felt they had enough similar pieces, they decided to “put their teeth” into the case, Cadena specifically says.
“The advantage was that we had many pieces, an interesting statistical population where we could see the variation in the characteristics of the teeth and say if they were consistent or not. We had teeth that were even broken and allowed us to see inside naturally, how the dentin (the tissue that is immediately below the tooth enamel), the enamel or the root varied, “explains the paleontologist.
It should be noted that Cadena has also been involved in important discoveries in the Colombian territorysuch as Titanoboa cerrejonensis, which is considered the largest snake in the world, and the Desmatochelys Padillai, the oldest sea turtle ever recorded.
“We started to realize that, just like with humans, we don’t need to have a skeleton to be able to tell if it’s a new species or not. We had hominid species defined only with jaws and teeth, our dental chart is unique in a certain way and the same happens with certain groups of animals, such as these sharks, whose teeth are very particular”, adds Dr. Cadena.
On the other hand, the expert states that sharks were not always a threatening species. “Not everyone was like that. Sharks over time have had different evolutionary and ecological adaptations, and this is one of them.”
“These sharks that we found were not adapted to tear, but to crush and that is why their teeth are flat. What they did was that when the prey arrived, they closed their jaws and instead of generating this tearcaused a crushing, ”says Cadena.
This work that is published today in the international journal of public access PeerJ, once again positioning the country with the paleontologists of the world, in the face of the contributions that Colombia has made in recent years to science.
In addition, this discovery shows the continuous and active process that Colombian paleontologists are leading and, in turn, adds to recent discoveries: insects, pterosaurs and giant tortoises that he leads the Neotropical Traditional and Molecular Paleontology Research Group (PaleoNeo), directed by the Professor Edwin Cadena.