The largest crocodile that lived in prehistoric dinosaurs: the alligator

U.S. researchers say that as fecal fossils and evidence of bone bite marks surfaced, the image of one of the largest crocodiles in prehistory, the crocodile, became more flesh-and-blood. The crocodile is a terrible member of the crocodile family, with the length of an extended luxury car. There is evidence that they may have lurked in shallow waters and waited for an opportunity to kill dinosaurs of their size.

The largest crocodile that lived in prehistoric dinosaurs: the alligator

The fossil feces found by the researchers are 79 million years old, the first known fossil of alligator feces. After analyzing the fossils, paleontologists announced their conclusions last week. The discovery of fossils of crocodile droppings has helped paleontologists understand the life of this giant crocodile. The areas where crocodiles once lived were what is now the United States and northern Mexico.

Fossils of crocodile droppings were found a few years ago in a river in Georgia. The researchers say the sand and shell fragments in the feces suggest that crocodiles prefer to live in estuaries — at least in Georgia, and the remains of crocodiles found by researchers are concentrated in estuarine areas — possibly feeding mainly on sea turtles.

Samantha Harel, a student at Columbus State University in Georgia, said the crocodiles in Georgia are relatively docile and "we're sure they're predators at the top of the food chain in this region." At a meeting of the Geological Society of America in Baltimore on March 17, Harel unveiled her findings.

In addition, the team found a shark tooth outside the fossil of crocodile feces. Since no traces of digestion were found on the teeth, the team believes the shark left the tooth when it was looking for food in crocodile feces. The researchers did not find bones or other indigested animal remains in the feces. Harrell said: "This is a welcome discovery. Because both modern and ancient crocodiles secrete digestive juices that can digest almost everything, including bones, horns and teeth. This finding just shows that the feces came from a crocodile. ”

Based on older evidence of bite marks, crocodiles clearly encounter more difficult prey outside of Georgia. At the Geological Society of America meeting, David Schweimer, a paleontologist at Columbus State University, presented this evidence. The bite marks left by the crocodile's teeth on the bones of its prey tell a story of a fierce contest of life and death. At the time, a 29-foot-long crocodile attacked dinosaurs of comparable size, including T. rex's close relatives, Monty Python's Apalachian and Alberosaurus. Schweimer said: "The bone healing signs we found show that the dinosaurs survived after being violently attacked by alligators. That is, it is clearly the predatory behavior rather than the scavenging behavior associated with this specimen. ”

Schweimer saw this strange, sunken egg-like trace for the first time on a georgia turtle fossil. Later, he saw similar traces on dinosaur skeleton fossils in Great Bend National Park in Texas and the National Museum in New Jersey. He said: "I realise these bite marks come from a really strong jaw and a lot of teeth. It is clear that this large blunt-toothed crocodile is the possible culprit. I haven't seen other animals leave tooth marks like this. ”

However, stephanie Drumhele, an expert on ancient crocodile bite marks, says tooth marks don't tell the whole story. "Modern crocodiles — crocodiles, American crocodiles, and related extinct crocodiles — are better at swallowing their prey whole and dividing large animals into lumps suitable for eating," he said. Evidence of bite marks is rarely left. So, we infer that behemoths like crocodiles may have even more destructive eating habits. ”

Although there is evidence of bite marks, it also raises the question: Why do crocodiles that can eat large dinosaurs waste energy on turtles? Two words: location. Modern crocodiles hunt a wide range and will eat any food they hunt in their own territory. The same factors may determine that individual crocodiles basically feed on turtles, or on dinosaurs or even other prey.

Paul Sereno, a paleontologist at the University of Chicago who discovered the 110 million-year-old emperor crocodile, also known as the Super Crocodile in Niger, points out that crocodiles native to North America also indicate that large crocodiles appear in different places and periods. Sereno, a resident explorer at the International Geographical Society, said: "Crocodiles and independent emperor crocodiles are two families, one older than the other, which proves that crocodiles can grow as large as dinosaurs. "Crocodiles lived only before the end of the Cretaceous Period, closer to modern crocodiles than emperor crocodiles, but they still can't escape extinction.

Sereno explains that an adult male crocodile may need to dominate miles of rivers in search of enough prey to survive. As a result, space constraints may have left crocodiles in small numbers, which also makes these large crocodiles more likely to become extinct in difficult times. Sereno said: "It seems that the right conditions for the survival of large crocodiles occasionally appear, but usually do not last long. "

Webmaster's Comments: In 1954, Edwin Harris Colbert and Roland T. Bird estimated the crocodile's jaw length at 1.85 meters, and compared it with other large crocodiles, proposed that the crocodile's body length was 15 meters. The 1997 ANMH 3073 specimen should have been disassembled for reasons such as misconstitution and needed to be recycled for research, and the original fossil was sent to the research area and no longer exhibited. According to the reconstructed versions from 1979 and 1997, the actual size of the skull of ANMH 3073 was 151-155 cm. The body length is more than 11 meters. Estimated 5500-7500kg.