As the strongest hunter in history, the Tyrannosaurus rex seemed to be perfect in everything: blood basin mouth, curved cone-like teeth, thick neck, developed hind limbs... However, there is only one thing that looks a little disappointing, and that is the tiny forelimbs that are disproportionate to their massive body shape. The nearly 13-meter-long body is equipped with only a pair of 1-meter-long forelimbs — only the length of an adult's arm, and it is not even possible to reach its own mouth. It was once thought that this was a degenerate structure that had no practical use anymore. Is this really the case?
Scientists have found that the forelimb bones of Tyrannosaurus rex are strong and have large muscle attachment areas, indicating that the pair of small forelimbs are stronger than they look, and should not be a structure that has been eliminated. There are several hypotheses about the function of the forelimbs of Tyrannosaurus rex:
(1) When the Tyrannosaurus rex is lying on the ground, it needs to use its forelimbs to prop up the front half of the body to stand up;
(2) Use the forelimbs to control the struggling prey when hunting;
(3) Grasp your spouse firmly when mating. Although it is not possible to directly observe how the Tyrannosaurus rex used its forelimbs, people still excavate the significance of the existence of these tiny forelimbs through detailed research and reasonable speculation.
In addition to the short forelimbs of Tyrannosaurus rex, a major feature is that they only have 2 toes, which is different from most carnivorous dinosaurs in that they have 3 toes. At first glance, this is a bit strange, but if you look closely at the other animals, it's really nothing. Quadruped "hands" usually have 5 toes, but many quadrupeds have degenerated or even disappeared "fingers", so there are 5-toed, 4-toed, 3-toed, and even 2-toed like T. rex in the quadruped family.
Riverside clawed dragon
In the dinosaur family, very primitive dinosaurs like Areera had 5 toes, but more progressive dinosaurs began to reduce the number of "fingers". Tyrannosaurus rex relatives generally retain 3 toes, but for some reason, the forelimbs of tyrannosaurus rex are only 2 toes. Some people speculate that this may be that the "hand" of the Tyrannosaurus rex has lost its hunting function and no longer needs to be grasped, so it is even more degraded.
However, Tyrannosaurus rex is not yet the dinosaur with the fewest "fingers". The forelimbs of the River-clawed dragon found in the Riverside region of Inner Mongolia, China, retain only 1 toe. Scientists speculate that the river-clawed dragon used its 1-toe "hand" to dig up ant nests and obtain nutrient-rich ants to feed itself. In this way, although the forelimb of the river clawed dragon has only 1 toe, this "finger" has a great role and has become a powerful tool for it to feed.