Species history of brachiosaurus

1900, Elmer S. Riggs and others discovered the first brachiosaurus specimen in grand canyon west, Colorado, USA. Type species, published and named by Elmer Riggs in 1903. Fossil consists of two bones, found in Morrison Formation (2nd to 4th and 6th floors) in Colorado and Utah, USA. The fossil period can be traced back to 65.438+0.5 billion years ago to 65.438+0.45 billion years ago, which is equivalent to Kaimolian period to Teton period. Compared with the long-necked dragon, brachiosaurus had shorter limbs and longer body.

A complete sauropod dinosaur skull found in Colorado, USA, which used to be classified as Pterosaur and Camarasaurus, was found to belong to Brachiosaurus in recent years. Brachiosaurus may be more primitive than other brachiosaurus, and it is a transitional species between primitive big-nosed dinosaurs and long-necked dinosaurs. B. nougaredi: 1960 was published and named by Albert Raber. The fossil contains some sacrum of forelimbs and buttocks, which was found in Valgra, Algeria, Africa. The survival period is estimated to be 654.38+ 1 100 million years ago, which is equivalent to the early Albian period of Cretaceous. Because the fossils are too scattered, the current state is in doubt. B. nougaredi lived behind brachiosaurus and long-necked dragon, so he probably didn't belong to brachiosaurus.

B. sp .: 1998, Kenneth Carpenter and others reconstructed the skull of beautiful Lei Long with othniel charles marsh, and identified it as the skull of Brachiosaurus sp. in North America. , may belong to brachiosaurus. This skull is more like a Camarasaurus than a long-necked dragon.

Long-necked dragon

1909, German paleontologist Werner Janensch discovered the specimens of sauropods near the call of East Africa (present-day Tanzania) in Germany, including five pairs of partial bones, including at least three skulls and some limbs. In 19 14, Werner Janis classified these specimens as new species of brachiosaurus and named them B. brancai. Brachiosaurus and Brachiosaurus brucei are estimated to have lived in similar times in the late Jurassic. They are similar in appearance, but brachiosaurus is primitive, with short limbs, high skull and short nose and mouth.

1988, Gregory S. Paul found that there were obvious differences between African brachiosaurus and North American brachiosaurus, especially the proportion of the body spine and the slender figure of brachiosaurus. Paul then established African brachiosaurus as a subgenus, brachiosaurus "B. (Giraffatitan) brancai". 199 1 year, George orshevsky thought these differences were enough to establish a new genus, so he turned brachiosaurus into an independent dragon with a long neck.

Since the long-necked dragon was named, the view that brachiosaurus and long-necked dragon belong to two genera has not been generally accepted by paleontologists. Apart from the research by Paul and Olshevski, it rarely appears in the scientific literature. In 2009, Michael Taylor published a detailed comparative study of Brachiosaurus and plesiosaur, and found that there were significant differences in their body shape, shape, body proportion and skull shape, so plesiosaur was an effective independent genus and did not belong to Brachiosaurus.

Luso Titan

1957, some Portuguese fossils were named B. attalla Brachiosaurus by Albert de Lapprand and g z Byszewski. Fossils are bones of some vertebrae, parts of pelvis and limbs, which were found in Estremadura. The fossil period can be traced back to the special period of late Jurassic. It was established as a new genus, Portuguese dragon, in 2003. The traditional feature of Brachiosaurus is a protruding skull, but now many scientists think this should be the feature of Brachiosaurus (long-necked dragon).

Brachiosaurus's skull has a strange shape, and there is a tall and curved bone column at the back of the head to separate the nostrils. The mouth is long and low, the jaw structure is firm, and the teeth are large and spoon-shaped. The ventricle is very small. This skull is more like Camarasaurus than brandti Brachiosaurus, so it is evidence of another genus that this skull has become a long-necked dragon. Brachiosaurus is one of the large dinosaurs in Jurassic. It lives on a grassland full of ferns, cycads and equisetum, and passes through a large number of forests of Pinaceae, Cycadaceae, tree ferns and ginkgo biloba. Dinosaurs living in the same area as Brachiosaurus included Stegosaurus, Oak Dragon, Puzzled Dragon and Liang Long. Some studies have speculated that small brachiosaurus would move in groups, while fully grown brachiosaurus was not too afraid of the largest hunting animals at that time, such as Allosaurus and Tyrannosaurus rex, because of its huge size.

For a long time, the nostril of Brachiosaurus was thought to be above its head, because it had corresponding nostril on its skull. In the past few decades, scientists thought that brachiosaurus's nostrils were like breathing tubes for diving, and it would dive into the water to support its weight most of the time. But recent studies have pointed out that brachiosaurus is actually a land animal, and water pressure will hinder their breathing. Their four feet are too narrow to move in the water. Furthermore, some scholars believe that the nostril of brachiosaurus is above the head of the eye, but the nostril is still at the front end of the nose and mouth. In the same study, it was also proposed that brachiosaurus's head bulged to accommodate some kind of fleshy cavity. Brachiosaurus liked to live in groups. They often went out in groups. Brachiosaurus's mother never built a nest when she gave birth to the next generation, but gave birth while walking, and her parents never cared. After the brachiosaurus baby is born, it can only grow up on its own.