Құрған динозаврлар туысы - Pelecanimimus

Extinct genus of dinosaurs

Pelecanimimus (meaning "pelican mimic") is an extinct genus of basal ("primitive") ornithomimosaurian dinosaur from the Early Cretaceous of Spain. It is notable for possessing more teeth than any other member of the Ornithomimosauria (or any other theropod), most of which were toothless.

In July 1993 Armando Díaz Romeral discovered a theropod skeleton at the Las Hoyas Unit 3 site. In 1994 this was named and described by Bernardino Pérez Pérez Moreno, José Luis Sanz, Angela Buscalioni, José Moratalla, Francisco Ortega and Diego Rasskin Gutman as a new species: Pelecanimimus polyodon. The generic name is derived from Latin pelecanus, "pelican", and mimus, "mimic", in reference to the long snout and throat pouch. The specific name is a reference to the large number of teeth possessed by this theropod and is derived from Greek πολύς (polys), "many" and ὀδούς (odous) "tooth". The holotype specimen, LH 7777, part of the Las Hoyas Collection presently housed at the Museo de Cuenca, Cuenca, Spain, of Pelecanimimus was recovered at the La Hoyas locality in Cuenca Province, Spain, from lagerstätte beds within the Calizas de La Huérguina Formation dating to the Lower Barremian. The only known specimen consists of the articulated front half of a skeleton and includes the skull, lower jaws, all the neck vertebrae and most of the back vertebrae, ribs, sternum, the pectoral girdle, a complete right forelimb and most of the left forelimb. Remains of the soft parts are visible at the back of the skull, around the neck and around the front limbs. Its skull was unusually long and narrow, with a maximum length of about 4.5 times its maximum height. It was highly unusual among ornithomimosaurs in its large number of teeth: it had about 220 very small teeth in total, with seven premaxillary teeth, about thirty maxillary, and seventy five in the dentary. The teeth were heterodont, showing two different basic forms. The teeth in the front of the upper jaw were broad and D shaped in cross section, while those further back were blade like, and on the whole the teeth in the upper jaw were larger than those in the lower. All of its teeth were unserrated, and had a constricted "waist" between the crown and the root. Interdental plates were lacking. Only one other ornithomimosaur is known to possess teeth, Harpymimus, which had far fewer (eleven total, and only in the lower jaw). The presence of such a large number of teeth in Pelecanimimus, coupled with a lack of interdental space, was interpreted by Pérez Moreno et al. as an adaptation for cutting and ripping, a "functional counterpart of the cutting edge of a beak," as well as an exaptation leading to the toothless cutting edge found in later ornithomimosaurs. Pelecanimimus was also the first ornithomimosaur discovered with a preserved hyoid apparatus (specialized tongue bones in the neck). This is due to the presence of large sternal plates and uncinate processes, which imply flight musculature. These adaptations have been noted years later by the paleontologist Mickey Mortimer.

The Las Hoyas lagerstätte has produced numerous other exquisitely preserved species, including the enantiornithine birds Iberomesornis, Concornis, and Eoalulavis, along with non avian theropod teeth, Concavenator remains, and a few fragmentary sauropod bones. Coarse sediments of the La Hoyas lagerstätte have produced bones of the ornithopod dinosaur Iguanodon. The lagerstätte beds have also yielded remains of lizards and salamanders, as well as of the unique early mammal Spinolestes. Several pterosaurs like Europejara and crocodylomorphs are also known.