The discovery of hand bone fossils of 140 million years of age suggests that the ability of modern humans to make and use complex tools may have originated much earlier than scientists had previously believed, the researchers said. One of the keys to the distinction between modern humans and all other living species is the ability to make complex tools. This is not only in the brains of very powerful people, but also in human hands, which gives this unique ability to human beings. On the contrary, humanoids, the relatives of humans' most intimate lives, lack the ability to grasp and create complex tools.
Continuous annealing furnace with furnace roll
Make various types of roller from small diameter (60mm) to large diameter (1600mm). In particular, the large diameter Furnace Roller used in continuous annealing production line with higher reliability is highly appraising. In addition, it also produces special roller for measuring temperature and equalizing temperature.
High speed wire rod mill at home, at the wire rolling mill, rod line and use of roller slit rolling mill ring, due to the work under the roll ring in relatively poor thermal conditions, therefore must be able to withstand the wear and corrosion of cooling water and the big rolling torque and so on, at present a lot of manufacturers adopt tungsten carbide tungsten carbide roll rings, but because the cost of tungsten carbide roll ring manufacturing high, caused the enterprise production costs rise, and in view of the actual situation, our factory successfully developed special wear-resistant alloy MSW66552 series, nearly half of the manufacturing cost is tungsten carbide, the effect of using basic tungsten carbide. The e product has been confirmed by the user, MSW66552 alloy product hardness 88HS, roll surface hardness difference less than 2HS, 6000C red hardness more than 82HS, roll body radial 30mm hardness difference less than 3HS, impact toughness more than 15J/CM2, fracture toughness more than 60Mpa. M1 /2.
Mill Roller,Hot Roll Steel,Stainless Steel Roller,Tungsten Carbide Roller Jiangsu Huaye Special Steel Manufacturing Co., Ltd. , https://www.huayecasting.com
The key feature of modern human hands is the third metacarpal bone, which is the middle finger connected to the bone of the wrist. "There is a small projection on the third metacarpal called the styloid process, that is what we need to use the tool." Roller Ward, an anatomist and paleoanthropologist at the University of Missouri, said, "This tiny bit of bone The palm helps to lock the metacarpal bones to the wrist, helping the thumb and the palm of the hand to exert a greater amount of pressure on the thumb and other fingers. Its overall characteristics are complex, and this dexterity and strength also make it part of our ability to make and use complex tools." Until now, this styloid process has only been found in ancient humans such as modern humans and Neanderthals. Scientists cannot determine when this bone first appeared in the process of human evolution. (Human descendants, sage, first evolved into about 25,000 years ago in Africa.)
The hand bone fossils have a history of approximately 1.42 million years. The researchers suspect that it belongs to humans who are exterminating humans and is indisputably the earliest predecessor of modern humans. The researchers hope to find an older hand bone to verify when this functional evolution has occurred.