Chinese scientists have discovered a new Jurassic nonavian theropod dinosaur from 163 million-year-old fossil deposits in northeastern China that provides new information regarding the incredible richness of evolutionary experimentation that characterized the origin of flight in the Dinosauria.
Published in Nature, Dr Wang Min of the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences in Beijing describes and analyzes the well-preserved skeleton of a new species of Jurassic scansoriopterygid dinosaur with associated feathers and membranous tissues.
The new species, named Ambopteryx longibrachium, belongs to the enigmatic clade the Scansoriopterygidae, one of the most bizarre groups of nonavian theropods.
The Scansoriopterygidae differ from other theropods in the proportions of their body plan, particularly in the proportions of the forelimb, which supports a bizarre wing structure first recognized in a close relative of Ambopteryx, Yi qi.
Unlike other flying dinosaurs, namely birds, these two species have membranous wings supported by a rodlike wrist bone (termed the styliform element) that is not found in any other dinosaur, but is present in pterosaurs and flying squirrels.
Until the discovery of Yi qi in 2015, such a flight apparatus was completely unknown among theropod dinosaurs – and its discovery in Yi qi was completely unexpected. Due to incomplete preservation in the holotype and only known specimen of Yi qi, the veracity of these structures and their exact function remained hotly debated.