A new member of the carcharodontosaur family suddenly appeared in the southern hemisphere, with a body length of more than 10 meters! The southern hemisphere during the Cretaceous was once dominated by carcharodontosaurs, so they were also called "shark kings." Paleontologists re

A new member of the carcharodontosaur family appears in the southern hemisphere, with a body length of more than 10 meters!

The southern hemisphere of the Cretaceous was once dominated by carcharodontosaurs, so they were also called the "shark kings". Paleontologists recently named a carcharodontosaurian dinosaur from South America. How is it different from other carcharodontosaurs?

Carcharodontosaurs of Campanas

South America's Argentina is the country of giant dragons. Not only are giant sauropods found here, including Argentinosaurus and Patagosaurus , large-scale carnivorous dinosaurs such as Giganotosaurus and Maposaurus were also discovered.

Note: Maposaurus preying on Argentinosaurus, pictures from the Internet

In 2012, paleontologists discovered new carcharodontosaurian fossils in the Huincul Formation (Huincul Formation) where Maposaurus was discovered, which was initially considered Called "Campanas carcharodontosaurid" (Campanas carcharodontosaurid), this fossil is numbered MMCh-PV 65. It includes a fairly complete skull, belt, limb bones and some vertebrae. This completeness It also makes it the most complete fossil of the carcharodontosaurid family in South America.

Caption: Fossil sites located in the interior of Argentina, pictures from the Internet

Caption: The dinosaur fossils discovered, pictures from the Internet

On July 7, 2022, paleontologists published a paper titled "New Discovery" in "Current Biology" The research paper "New giant carnivorous dinosaur reveals convergent evolutionary trends in theropod arm reduction" (New giant carnivorous dinosaur reveals convergent evolutionary trends in theropod arm reduction) named this dinosaur Meraxes (Meraxes). It comes from the dragon "Meraxes" in "A Song of Ice and Fire ", but it did not appear in the American TV series "A Song of Ice and Fire". The type species of Meraxes is Meraxes gigas ( Meraxes gigas). The species name comes from Latin , which represents its huge size.

Note: The giant dragon in "A Song of Ice and Fire", the picture comes from the Internet

The guy with wrinkles on his head

The name of the Meraxes dragon species is "giant" because it really has a huge body shape, its length Between 9.7 and 11 meters, the weight is about 4.2 tons . Among the carcharodontosaurs, Melasisaurus surpassed Acrocanthosaurus in size and became the fifth largest carcharodontosaur in . At the same time, all the top five carcharodontosaurs were produced in Southern Hemisphere.

Note: Comparison of the size of Meraxesaurus and humans, the picture comes from the Internet

The huge Meraxesaurus only has a head length of 1.3 meters. Since most of the skull fossils have been preserved, it not only shows the huge head of Melasisaurus, but also can see two protrusions on the top of its head and a structure full of folds . This structure extends from the top of the nostrils to the top of the eyes. It makes its head look very domineering. Paleontologist Juan Canale believes these structures likely appeared on adult dinosaurs to attract mates. In addition to the fold structure, the most eye-catching thing on the head of Meraxesaurus is its bloody mouth full of sharp teeth, which is also its most important killing weapon.

Note: The gray part is the found part of the skull of Mirasesaurus. The picture comes from the Internet.

. Note: Comparison of the skull of Mirasesaurus with humans. The picture comes from the Internet.

. Behind the big head of Mirasesaurus is a thick neck. It has a wide body and a long tail for balance. Melasisaurus walked on two legs, so its hind limbs were quite strong and were particularly short compared to its previous forelimbs.In fact, the forelimbs of Melasisaurus are shorter than those of other carcharodontosaurs, and can even compete with Tyrannosaurus rex. However, compared with Tyrannosaurus rex, Melasisaurus has three long forelimbs. Instead of two fingers, the appearance of short hands is also to balance the change in the center of gravity of the body as the head becomes larger.

Note: Milasisaurus walking upright on two legs, the picture comes from the Internet

The long-lived emperor

Milasisaurus lived in the early Late Cretaceous period between 595 million and 94 million years ago, and its fossils were discovered Other famous dinosaurs have also been discovered in the Winkur Formation, including the sauropods Argentinosaurus and Choconosaurus, and the theropods Guarijoosaurus, Scorpionvenator, Thunderosaurus, and Muscle dragon and so on. In addition to these dinosaurs, there are also Melasisaurus and Maposaurus, which belong to the Carcharodontidae family. Maposaurus is larger and more ferocious than Melasisaurus.

Note: The dinosaurs of the Winkur Formation, the pictures are from the Internet

Judging from the stratum where the fossils were found, Melasisaurus may have lived earlier than Maposaurus, so they may not have had the chance to meet, m In this way, Lacisosaurus became the top predator of its time.

Note: The huge and powerful Mirasisosaurus, the picture comes from the Internet

Another feature of Mirasisosaurus is its age. Analysis of its bone tissue shows that it was 53 years old when it died. This is also The longest-lived non-avian theropod dinosaur at present is really an old king. The reason why Melasisaurus is so long-lived is partly due to its good luck, and partly because its development is slower than we thought. It only reached maturity between 30 and 40 years old, which is really a late maturity.

The discovery of Milasisaurus has enriched our understanding of the Carcharodontosauridae. This family once firmly controlled South America, but some of them had smaller forelimbs and enlarged heads similar to Tyrannosaurus rex. wait.

Paper: Canale, J.I.; Apesteguía, S.; Gallina, P.A.; Mitchell, J.; Smith, N.D.; Cullen, T.M.; ). "New giant carnivorous dinosaur reveals convergent evolutionary trends in theropod arm reduction". Current Biology.

Picture/From the Internet, infringement and deletion of

text/Microraptor Jiangshi (Jiang Hong)

Typesetting/Microraptor Jiangshi