Study uncovers secret to their longevity

Most people think of crocodiles as living fossils – unchanged, prehistoric relics that have ruled the fearless corners of the world for millions of years. But his evolutionary history tells a different story, according to new research led by Central Oklahoma University and Utah University.

Crocodilians survive members of a 230 million-year dynasty, called crocodilomorphs, a group that includes living crocodiles (ie crocodiles, crocodiles and households) and many of his extinct relatives. Crocodilian ancestors remained through two large -scale extinction incidence, an achievement that requires evolutionary agility to adapt to the rapidly changed world.

The authors of the study found that a mystery for the longevity of crocodiles is their remarkable flexible lifestyle, both in both of them and the habitat in which they receive it.

“Many groups belonging to crocodiles were more diverse, more abundant, and demonstrated separate ecology, yet they all disappeared leaving some of these generalist crocodiles,” said the prominent writer and assistant professor of UCO Keagan Melstrom, who started research as a doctoral student at the university.

“Extracting and survival are two sides of the same coin. Through all mass extinction, some groups manage to bring firmness and diversity. What can we learn by studying the deep evolutionary patterns provided by these events?”

Prithvi has experienced five large -scale extinction in its history. Experts argue that we are living through a sixth, the habitat is inspired by destruction, aggressive species and changing climate. Identifying the symptoms promoting survival during the upheaval of the planets can help scientists and protectionists in better protection of weak species today.

Historically, the region has considered the posters as children to understand the existence of mass extinction of mammals, appreciating their common diet and the ability to flourish in various ecosystems. Despite their flexibility, research has largely ignored crocodilomorf clades.

The paper, published in the journal FossilismThe diet of crocodiles to identify the characteristics is the first to re-organize the ecosystem, which helps some groups to stay and flourish through two mass extinct-an end-shat, about 201.4 million years ago (MA), and end-current, about 66 mA.

“There is a danger of trying to conclude from millions of years in advance and has been applied to direct protection. We have to be cautious,” said Randy Ermis, the curator of peliyontology in the Natural History Museum of Utah and Randy Ermis, co-writer of Professor in the Department of Curator and U-Geology.

“If people study mammals and reptiles and get the same pattern in relation to the existence of extinction, we can guess that species with a common diet can improve. This information helps us to make predictions, but it is unlikely that we will never choose which personal species will survive.”

A hidden past of alternative lifestyle

Living crocodilians are famous for being a semi-semi-generalist, which flourish in the environment such as lakes, rivers or marshes, waiting for the unheard prey to ambush. Pick eaters, they are not.

Young people will snack anything from tadpol, insects or crustaceouses before graduating from large fare, fish, baby deer, or even fellow crocodiles. Nevertheless, in the uniform lifestyle of today’s crocodiles, there is a large variety of diet ecology in which previous crocodilomorphs thrive.

During the late trichic period (237–201.4 mA), a comprehensive evolutionary group, pseudosuchia, which includes early crocodilomorf and many other extinct linearies ruled the land. The first crocodilomorfs were small-to-middle-shaped creatures that were rare in their ecosystem, and carnivorous that were mostly eaten by small animals.

In contrast, other Pseudosuchian groups dominated the land, captured a wide range of ecological roles and demonstrated a dizzy variety of body shapes and sizes.

Despite their dominance, once the end-trix was extinct, no non-crocodileomorf pseudosuchian survived. While the hyper-carnivor Crocodilomorf also appeared to die by terrestrial generalists. The writers envisage that almost this ability to eat anything allowed him to survive, while many other groups became extinct.

“After that, it goes to the banana,” Melstrom said. “Aquatic Hyperakainivorus, terrestrial generalist, terrestrial hyperranivorus, terrestrial vegetarian – Crocodlomorfs developed a large number of ecological roles during dinosaur time.”

Something happened during the late Creteseous period that sets crocodilomorphs on a decline. Specific genealogies for diverse ecology began to disappear, even terrestrial generalist.

Most of the people survived are a group of semicircular and aquatic carnivores, by the occurrence of extinction (puncture by meteor killing non-avyon dinosaurs), an end-consorteus mass. Today’s 26 species species of crocodiles are almost all semi -generalist.

Beyond the smile of a crocodile

How did scientists cross the food on the multi-military-year menu? They analyze fossil teeth and skull -shaped to brighten the base of an animal’s diet. A jaw is likely to stand with a small knife and was puncturing the meat.

A mortar-and-mellet-like grill probably broke the tissue of the plant. The size of the skull determines how an animal takes his mouth, which provides a clue of his food habits. Understanding ancient animal foods shows where it will be victims, which the author is called diet ecology.

It was a huge venture. The authors visited Zoological and Peliantological Museum Collections in seven countries and four continents, so that they could achieve fossil samples. He examined the skulls of 99 extinct crocodile species and 20 living crocodile species, making a fossil dataset in evolutionary history of 230 million years.

Researchers had earlier created one Database Including 89 mammals and 47 lizard species, to live with non-cocodilians to compare with. The samples represented a series of diet ecology, ranging from strict carnivorous to herbs, and different types of skulls.

As semi -ambush predators, today’s crocodiles have occupied the same ecological roles in most various environments. They continue remarkably flexible diets, perhaps a remnant of their deep diverse evolutionary past.

For severely endangered crocodiles like Cuban’s crocodile crocodiles of the Himalayas foothills or the country’s Japata swamp, dietary flexibility can give them a chance to remain through our current sixth mass. The biggest challenges in front of these species are housing loss and human prey.

“When we look at living crocodiles and crocodiles, instead of thinking about cruel animals or expensive handbags, I hope that people appreciate their amazing 200+ million years of development, and how they have survived so many events in the history of Earth,” said Irris.

“Crocodiles are equipped to avoid many future changes – if we are ready to help preserve their houses.”