Six cervical vertebrae are articulated with each other, with a total length of 165 cm. The width of each vertebral body greatly exceeds its height. Finally, 1 The cervical vertebra is quite long, reaching 30 cm. All vertebral bodies are flat and concave, and the posterior end is thicker than the anterior end. The cervical ribs are particularly short. The average length of each cervical vertebra is roughly smaller than that of the spine. Vertebra has two vertebrae representing two individuals, namely, 9, 6 and 4 hinged to each other. Nine of the joints are well preserved. The vertebral body is flat and sunken, with strong contraction in the middle, no lateral depression and dense internal structure. The nerve spine is upright, rectangular, wide, longer than the width, and located in the middle and posterior part above the vertebral body. It suddenly reaches horizontally, extends horizontally to both sides, and the accessory process is small and oval.
The spine of Gongxian dragon in the stone tablet
(a) Vertebra and dorsal rib of 9 joints, ×113.8; (b) The vertebra with 6 joints, x116.2, is rich in dorsal ribs and abdominal ribs, which can be preserved in two ways: one is the joint with the vertebra, such as the joint with 9 vertebrae (Figure 3); The second is dispersion, without certain directionality. However, in both cases, most individuals' dorsal ribs are well preserved and have two heads. The middle dorsal rib is the longest and the maximum curve length can reach 150 cm. Abdominal ribs are smaller than dorsal ribs and are not preserved with spinal joints. The sacrum remains between the left and right intestinal bones, and there are three * * *, which heal each other and are biplanar, and the middle part contracts. Nerve prick. That is, the front three coccygeal vertebrae, the front 12, and the middle and back eight. The first three vertebral bodies contract in the middle, thicker and shorter, which is similar to the recommended vertebrae. Both nerve spines and transverse processes are broad plates. The whole vertebral body is poorly preserved. 12 coccyx is well preserved. The specimen is buried on the side, with the right side facing up, double concave shape and strong contraction in the middle. There is no obvious grid structure. The nerve spines are wide and plate-shaped, slightly backward, with thin sides. Transverse process is also very developed, wide plate-shaped, extending outward and upward. The pulsed arc is very long and does not diverge. The total height of the second and third pulse arcs is 72 cm respectively.
The shoulder strap includes the scapula, coracoid and sternum (Figure 5). It's well preserved. The entire scapula is very thin. The proximal and distal ends are obviously expanded, and the middle part is narrowed and folded back into a regular arc. The outline of coracoid bone is nearly semi-circular, in flat contact with scapula, and there is no coracoid hole. There are 3 pairs of sternum * * *, each pair is different in size, but its left and right sternum are symmetrically arranged in a nearly round diamond shape.
The forelimb has four humerus, three of which are well developed with scapula and triangular crest, and the length is about 80% of femur. The flexor and ulna specimens are worse than the humerus, and the length is 54% ~ 65% of the humerus, and the ulna (not mature individuals) is 60% of the humerus.
Forefoot, including wrist, metacarpal and phalanx, has not been preserved. The belt has only one left and right intestine bone, pubic bone and ischium (only the proximal end), which is not well preserved due to severe weathering. The rear end of the left intestine is blunt, and the rear end of the right intestine is round. The pubic bone is wide and the left and right pubic bones are in complete contact. The intact hind limbs, including femur, tibia, fibula and hind foot, are well preserved. The femur is the left femur, as above. There is no obvious dividing line between the femoral head and the shaft. Length115cm. The tibia and fibula only remain in the left hind limb, which is not obviously different from other sauropods. The fibula is 66% of the femur length, and the tibia is 665438+ 0.7% of the femur length. The tibia is strong and the distal ankle is well developed. Except for the first leg, the rear foot material has a left rear foot that is engaged with the rear leg. Other bone parts are intact. The right hind foot was buried alone, and the talus and calcaneus were missing. Its toe type is 2,3,4,5, 1. 1, 2, 3 and 4 toes all have claws, that is, the hind foot has four claws, and there are no lateral grooves on both sides of the trailing edge of the claws. 3. After preliminary research, identification and discussion, the proportion of forelimbs of General (II) in Liao Dynasty increased obviously, accounting for 70% ~ 75% of the length of hind limbs, belonging to the proportion range of sauropods; (3) The phalanx is thick and short, with no lateral fossa on both sides of the front end, thick claw bone and no longitudinal groove on both sides of the back; (Ⅳ) According to the anatomical principle, its total individual length is about 14 m (Figure 6), which is longer than the known protosauropods. However, there are significant similarities between the male Xianlong and the protosauropod: (1) the premolars have developed kyphosis; (2) The internal structure of the anterior vertebral body is firm, and there is no reticular structure and lateral concavity; (iii) The pulsed arc is not bifurcated; (Ⅳ) Abdominal ribs; (ⅴ) Three sacrums, which are mutually healed; (6) The toe type is 2, 3, 4, 5, 1. In addition, there are short neck ribs, nearly rectangular upright neck with simple structure, dorsal spine, and so on.
In a word, Gongxianlong not only has some characteristics of sauropods, but also has many similarities with primitive sauropods, and is a transitional type of evolution from primitive sauropods to sauropods.