long tail was present and mistook grooves in the jaw bones for small degenerated teeth. Skull The skull morphology of Confuciusornis has been difficult to determine, due to the crushed and deformed nature of the fossils. The skull was near triangular in side view, and the toothless beak was robust and pointed. The front of the jaws had deep neurovascular foramina and grooves, associated with the keratinous rhamphotheca (horn-covered beak). The skull was rather robust, with deep jaws, especially the mandible. The tomial crest of the upper jaw (a bony support for the jaw's cutting edge) was straight for its entire length. The premaxillae (front bones of the upper jaw) were fused together for most of the front half of the snout, but were separated at the tip by a V-shaped notch. The frontal processes that projected hindwards from the premaxillae were thin and extended above the orbits (eye openings) like in modern birds, but unlike Archaeopteryx and other primitive birds without pygostyles, where these processes end in front of the orbits. The maxilla (the second large bone of the upper jaw) and premaxilla articulated by an oblique suture, and the maxilla had an extensive palatal shelf. The nasal bone was smaller than in most birds, and had a slender process that directed down towards the maxilla. The orbit was large, round, and contained sclerotic plates (the bony support inside the eye). A crescent-shaped element that formed the front wall of the orbit may be an ethmoidolacrimal complex similar to that of pigeons, but the identity of these bones is unclear due to bad preservation, and the fact that this region is very variable in modern birds. The external nares (bony nostrils) were near triangular and positioned far from the tip of the snout. The borders of the nostrils were formed by the premaxillae above, the maxilla below, and the nasal wall at the back. Few specimens preserve the sutures of the braincase, but one specimen shows that the frontoparietal suture crossed the skull just behind the postorbital process and the hindmost wall of the orbit. This was similar to Archaeopteryx and Enaliornis, whereas it curves back and crosses the skull roof much farther behind in modern birds, making the frontal bone of Confuciusornis small compared to those of modern birds. A prominent supraorbital flange formed the upper border of the orbit, and continued as the postorbital process, which had