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(CNN) – A massive, extinct reptile that once looked for dinosaurs had a wide snout like an alligator, but it owed his success to a feature that lacks modern alligators: tolerance to salt water.
Deinosuchus was one of the largest crocodile that have ever lived, with a body almost as long as bus and teeth the size of bananas. From around 82 million to 75 million years, the top predator swam in rivers and river mouths in North America. The skull was wide and long, tilting with a lump of tubers, which was seen in other crocodiles, among other things. Dental markings on chalk bones indicate that Deinosuchus hunted dinosaurs or removed.
Despite his scientific name, which means “terroric crocodile”, Deinosuchus was generally referred to as the “larger alligator”, and earlier assessments of his evolutionary relationships grouped it with alligators and their old relatives. A new analysis of fossils together with DNA of living crocodiles such as alligators and crocodiles indicates that Deinosuchus belongs to another part of the crocodile trunk tree.
In contrast to alligatoroids, Deinosuchus kept the salt glands of ancestral crocodiles, so that it tolerated salt water, reported on Wednesday in the Journal Communications Biology. Modern crocodiles have these glands that collect and release excess sodium chloride.
Salt tolerance would have contributed to navigating the western interior, which once shared North America during a greenhouse phase, which was characterized by the global increase in sea level. Deinosuchus could then have spread over the continent in order to live on both sides of the old inland sea and along the North America’s Atlantic coast coastal sammer.
The revised family tree of the new study for crocodiles offers new insights into climate silence in the group and indicates how some types adapted to environmental cooling while others were extinct.
With salt glands that enable Deinosuchus to travel where his alligatoroid cousins could not be able to, the terroric crocodile settled in habitats. Deinosuchus developed into an enormous and widespread predator that dominated swampy ecosystems, where it dealt with pretty much everything it wanted.
“Nobody was safe in these wetlands when Deinosuchus was nearby,” said Senior Study author Dr. Márton Rabi, lecturer at the Institute for Geosciences at the University of Tübingen in Germany. “We are talking about an absolutely monstrous animal,” Rabi told CNN. “Definitely about 8 meters (26 feet) or more body length.”
Research authors (from left) Jules D. Walter and Dr. Máron Rabi from the University of Tübingen in Germany examine the skulls of the existing crocodiles, including those of people in the institute’s zoology. – Márton Rab/University of Tübingen
An outlier among alligators
Since the middle of the 19th century, fossils of Deinosuchus have been found on both sides of the old sea and at least two species. The biggest of Deinosuchus Riograndensis lived on the west side on the east coast of an island called Laramidia. Laramidia on the west of the Pacific Ocean was less than a third of the land mass of North America. The other island section of the continent was known as Appalachia.
While Deinosuchus had been classified as an alligator for a long time, his distribution on both sides of this huge sea was an unsolved puzzle. If it were an alligatoroid – a group that only lives in fresh water today – how could Deinosuchus cross a sea that crosses more than 620 miles (1,000 kilometers)? A hypothesis indicated that early alligators were salt water tolerant and later lost the characteristic. However, this interpretation did not have many evidence to secure it. It only depended on that Deinosuchus was included in the Alligatoroid group, explained Rabi.
Another possible explanation was that Deinosuchus distributed itself to North America before the western domestic traffic formed and shared western and eastern population. However, the fossil stock does not support this. The Seaway performed about 100 million years ago and made it about 20 million years older than the earliest known Deinosuchus fossils.
“The picture was not very coherent,” said Rabi.
For the new analysis, the researchers recorded data from extinct crocodiles that were not questioned for the group’s former family trees. These “missing connections” helped the team to connect species that were not previously related and re -assemble the order in which certain characteristics were created in the group.
“Our analysis showed that salt water tolerance is a fairly old feature of many crocodiles and secondly was lost in the alligatoroids,” said Rabi. A moderate tolerance of salt would have benefited the old crocodile relative because the climate redesigned its habitats, said Dr. Evon Hekkala, professor and chairman of the Ministry of Biosciences at Fordham University in New York City.
“In the past, this ecological feature would have enabled the lines of crocodiles in times when drastic environmental changes, such as the sea level, were opportunistic, were enabled in less tolerant species,” said Hekkala, who was not involved in the study.
No “larger alligator”
The researchers also constructed a new crocodile stem tree using molecular data from modern crocodiles in order to clarify the characteristics shared by all alligatoroids. The earliest alligators were far smaller than other crocodiles who lived at the same time, the team found. Alligators began to develop the larger body sizes that were seen today about 34 million years ago after the climate had cooled down and their competition had died out. But as an alligatoroid for the first time, Deinosuchus would have been an outlier due to its massive mass, according to the new study.
The dwarf change in early alligatoroids was another indication that the giant Deinosuchus was not a “larger alligator” and probably deviates to another branch of the family tree before alligatoroids developed, Rabi said.
The study of the study, which combines a new molecular tree with morphology or analysis of body and skull shapes in crocodiles – paints a clearer picture of how Deinosuchus has developed, said Hekkala. Deinosuchus to push away from alligatoroids, “” much better suits our current understanding of ecological flexibility among the extinct and living crocodiles, “she added. “This new paper applies to both the evolutionary and the ecological role of this amazing animal.”
While Deinosuchus was one of the biggest crocodiles, it was not the only giant. Massive crocodiles have developed over the past 120 million years in all types of global climate phases – including ice ages, in the past 120 million years, according to the study, more than a dozen in the aquatic environments. Even with living species, there was reports of people who measure 23 feet (7 meters) or more up to the 19th century, which indicates that an enormous Deinosuchus was more the rule than the exception.
“Giant Crocs are more of the norm – at a time,” said Rabi.
Mindy Weisberger is a scientific author and media producer whose work has been published in Live Science, Scientific American and How IT Works Magazine.
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