A new anurognathid pterosaur specimen from the Middle Jurassic Tiaojishan Formation of Qinglong, northern Hebie Province is described. The new specimen is referred to Dendrorhynchoides, based on the general morphology...A new anurognathid pterosaur specimen from the Middle Jurassic Tiaojishan Formation of Qinglong, northern Hebie Province is described. The new specimen is referred to Dendrorhynchoides, based on the general morphology of the skeleton, but it represents a new species, named here as Dendrorhynchoides mutoudengensis sp. nov.. It is characterized by the presence of short, robust and straight teeth, and bearing wing metacarpal approximately 40% of the length of humerus. The new specimen provides further osteological information for anurognathid pterosaurs, especially the presence of a relatively elongate tail.展开更多
Tapejara wellnhoferi, a small azhdarchoid pterodactyloid from the Early Cretaceous Santana Formation of Brazil, provides critical information about the aerodynamic function of its spectacular head crest. The cranial c...Tapejara wellnhoferi, a small azhdarchoid pterodactyloid from the Early Cretaceous Santana Formation of Brazil, provides critical information about the aerodynamic function of its spectacular head crest. The cranial crests in pterodactyloids were sexually dimorphic and are thought to have evolved in adult males in response to female mate choice. However, the location of cranial crests in front of the center of gravity would create instability in the yaw axis during flight and may seem like a handicap. Vertically aligned webbed feet probably suppressed the yawing rotations and instability from the crest. Here we show that the crest functioned as a front rudder to make agile turn and mediate flight control. A computer simulation model suggests that Tapejara had a large excess of muscle power available above the power required for continuous flapping flight. It could easily takeoff from a perch, ground, or water surface and land safely on the ground. It was an excellent glider with a gliding angle close to 4~ and a cruising speed of 27 km/h. Tapejara could soar efficiently on the windward side of cliffs or circle on rising thermals over tropical waters for efficient long-distance flight. Various control surfaces in the wings of Tapejara analogous to the slat, aileron, elevator, fin, rudder, and horizontal stabilizer of an aircraft made pterodactyloids versatile flyers.展开更多
基金supported by grants from the Natural Science Foundation of China (9091400340872017)the Basic Outlay of Scientific Research Work from the Ministry of Science and Technology (2011-SYS-02)
文摘A new anurognathid pterosaur specimen from the Middle Jurassic Tiaojishan Formation of Qinglong, northern Hebie Province is described. The new specimen is referred to Dendrorhynchoides, based on the general morphology of the skeleton, but it represents a new species, named here as Dendrorhynchoides mutoudengensis sp. nov.. It is characterized by the presence of short, robust and straight teeth, and bearing wing metacarpal approximately 40% of the length of humerus. The new specimen provides further osteological information for anurognathid pterosaurs, especially the presence of a relatively elongate tail.
文摘Tapejara wellnhoferi, a small azhdarchoid pterodactyloid from the Early Cretaceous Santana Formation of Brazil, provides critical information about the aerodynamic function of its spectacular head crest. The cranial crests in pterodactyloids were sexually dimorphic and are thought to have evolved in adult males in response to female mate choice. However, the location of cranial crests in front of the center of gravity would create instability in the yaw axis during flight and may seem like a handicap. Vertically aligned webbed feet probably suppressed the yawing rotations and instability from the crest. Here we show that the crest functioned as a front rudder to make agile turn and mediate flight control. A computer simulation model suggests that Tapejara had a large excess of muscle power available above the power required for continuous flapping flight. It could easily takeoff from a perch, ground, or water surface and land safely on the ground. It was an excellent glider with a gliding angle close to 4~ and a cruising speed of 27 km/h. Tapejara could soar efficiently on the windward side of cliffs or circle on rising thermals over tropical waters for efficient long-distance flight. Various control surfaces in the wings of Tapejara analogous to the slat, aileron, elevator, fin, rudder, and horizontal stabilizer of an aircraft made pterodactyloids versatile flyers.
