A new species of giant crocodile, known as Machimosaurus rex, has been discovered by researchers in Tunisia, with the individual said to have weighed around 3,000 kg and measuring 10 metres in length. The finding, published in the journal Cretaceous Research, serves to shed light on crocodilian evolution about 112 million years ago, during the Late Cretaceous Period, and highlights the diversity of the species. Research in the area is set to continue, as scientists aim to answer further questions on how crocodiles disperse and evolve through different continents, among other data points.
Giant Prehistoric Crocodile Discovered in Africa
A new species of giant crocodile that lived millions of years ago in what is now Tunisia has been identified by an international team of researchers led by Federico Fanti of the University of Bologna. Dubbed Machimosaurus rex, or “king of the seas,” the massive reptile measured up to 10 meters (33 feet) long and weighed as much as 3,000 kilograms (6,600 pounds), making it one of the largest crocodiles ever known. The discovery, described in a paper published in the journal Cretaceous Research, sheds light on the evolution of crocodilians during the Late Cretaceous period, around 112 million years ago, when many marine reptiles and dinosaurs still roamed the planet.
Discovery and analysis
The first fragmentary remains of Machimosaurus rex were found in 2014 by a team of Italian and Tunisian paleontologists in the phosphate mines of Oum El Khangua, near the coastal city of Gabès. At the time, the researchers thought they had discovered a new species of the genus Machimosaurus, which included several other crocodiles that lived in the same area during the Cretaceous, but they could not confirm the identity of the animal due to the limited fossils available. In 2019, the team returned to the site and collected more bones, including skull fragments, teeth, limb bones, and some vertebrae, for a more detailed study.
Using computed tomography (CT) scans, digital reconstruction, and phylogenetic analysis, the researchers were able to reconstruct the anatomy of Machimosaurus rex and compare it to other crocodiles from different periods and regions. They found that the new species had several features that distinguish it from other Machimosaurus, such as a triangular snout, large teeth, and a distinct pattern of cranial sutures. They also estimated that Machimosaurus rex had a longer and more streamlined body than its relatives, suggesting that it was a fast swimmer that hunted in open seas, unlike most crocodiles today that prefer freshwater habitats.
Implications and questions
The discovery of Machimosaurus rex adds to the diversity of crocodilians that existed during the Late Cretaceous and highlights the adaptability and ecological diversity of this group of archosaurs that has survived for about 230 million years. The finding also raises some questions about the paleobiology and biogeography of Machimosaurus and its relatives. For example, how did these crocodiles disperse and evolve across different continents, from Europe to Africa to South America, during the middle and late Jurassic and Cretaceous? What were the environmental factors that influenced their range and adaptation? What were the interactions of these crocodiles with other marine predators, such as mosasaurs and plesiosaurs? How did they cope with the sea level changes and global climate variations that occurred during their long history? These and other puzzles are still waiting to be solved by future research.
Q: What is a crocodilian?
A: A crocodilian is a group of reptiles that includes crocodiles, alligators, caimans, and gharials. They are characterized by a long snout, a powerful tail, and a semi-aquatic lifestyle.
Q: How long have crocodilians existed?
A: Crocodilians appeared in the fossil record in the Late Triassic, around 230 million years ago. They lived alongside and diversified with dinosaurs and other archosaurs during the Mesozoic era.
Q: Are crocodiles considered dinosaurs?
A: No, crocodiles are not considered dinosaurs, although they are closely related to them. Dinosaurs belong to a different group of archosaurs that are more diverse and varied in their body forms and behaviors.
Q: How rare is the discovery of a new crocodile species?
A: It depends on the area and the time period. Some parts of the world have more known species of crocodiles than others. Also, some epochs have more fossil evidence than others. However, most recent crocodile discoveries tend to be variations or subspecies of known genera, rather than entirely new lineages.
Q: How are crocodile fossils preserved?
A: Crocodile fossils are often found in sedimentary rocks, such as sandstone and limestone, that were deposited in or near bodies of water. The bones are usually disarticulated and scattered, but sometimes they are preserved in more complete skeletons or even soft tissues, such as skin imprints or teeth marks on bones. The quality and extent of preservation depend on various factors, such as the depositional environment, the age of the fossils, and the interaction with other organisms and physical processes.