Psittacosaurus Research Papers
Psittacosaurus
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Anthony DeNike
The Natural History of Dinosaurs (Eart 65)
UC Santa Cruz
5/23/11
Psittacosaurus is a genus of the psittacosaurid ceratopsian dinosaur from the Early Cretaceous Period, and represents one of the most primitive conditions of the ceratopsians (Fastovsky and Weishampel, 2009). Psittacosaur is Greek for ‘parrot lizard’, and receives such a name due to its skull being ‘parrot-beaked’, and is characterized by its short, deep snout and ventrolaterally projecting cheek horns (Sereno, 2010). It is a small bipedal dinosaur, with a very broad geographical distribution throughout Asia, and one species found in Russia. Psittacosaurs date back approximately 100 to 130 million years ago. They are recognized …show more content…
On October 19, 1923, he published a paper on the dinosaur, naming the first of many psittacosaur species: Psittacosaurus mongoliensis. The remains of this dinosaur were first discovered the year before, on the third American Museum of Natural History expedition to the Gobi Desert of Mongolia (Osborn, 1923). Since this discovery, approximately 18 more species have been assigned to the ceratopsian genus Psittacosaurus, although only twelve to fourteen are considered valid (Zhao et al., 2007). This is the highest number of valid species currently assigned to any single dinosaur genus (not including birds). This fact makes psittacosaurus very unique, compared to other dinosaur genera, many of which are monospecific, containing only a single known species (Sereno, 2000). With such a large amount of psittacosaur remains discovered, the diversity of the dinosaur can be viewed in a more complete fashion compared to that of many other dinosaur genera, which would be the reason for so many species being recognized. Fossil remains of over 75 psittacosaur individuals have been recovered, including nearly 20 complete skeletons with skulls (Lucas, 2006). Although there are up to fourteen named species, some paleontologists such as Zhae et al. (2006) believe taxonomic revision of the psittacosaur genus is overdue and it is probable …show more content…
Evidence which supports this is that they had self-sharpening teeth, appearing to have been useful for slicing tough plant material. While their teeth were sharp enough to slice, they were not capable of grinding or chewing food efficiently, unlike their later ceratopsian decendents. In place of chewing the plant material, they used gastroliths which would wear down food as it passed through the digestive system. There have been cases in which more than fifty gastroliths are found in the abdominal cavities of psittacosaurs, and may have been stored in a gizzard, as in modern birds (Peter and You,
[pic]
Anthony DeNike
The Natural History of Dinosaurs (Eart 65)
UC Santa Cruz
5/23/11
Psittacosaurus is a genus of the psittacosaurid ceratopsian dinosaur from the Early Cretaceous Period, and represents one of the most primitive conditions of the ceratopsians (Fastovsky and Weishampel, 2009). Psittacosaur is Greek for ‘parrot lizard’, and receives such a name due to its skull being ‘parrot-beaked’, and is characterized by its short, deep snout and ventrolaterally projecting cheek horns (Sereno, 2010). It is a small bipedal dinosaur, with a very broad geographical distribution throughout Asia, and one species found in Russia. Psittacosaurs date back approximately 100 to 130 million years ago. They are recognized …show more content…
On October 19, 1923, he published a paper on the dinosaur, naming the first of many psittacosaur species: Psittacosaurus mongoliensis. The remains of this dinosaur were first discovered the year before, on the third American Museum of Natural History expedition to the Gobi Desert of Mongolia (Osborn, 1923). Since this discovery, approximately 18 more species have been assigned to the ceratopsian genus Psittacosaurus, although only twelve to fourteen are considered valid (Zhao et al., 2007). This is the highest number of valid species currently assigned to any single dinosaur genus (not including birds). This fact makes psittacosaurus very unique, compared to other dinosaur genera, many of which are monospecific, containing only a single known species (Sereno, 2000). With such a large amount of psittacosaur remains discovered, the diversity of the dinosaur can be viewed in a more complete fashion compared to that of many other dinosaur genera, which would be the reason for so many species being recognized. Fossil remains of over 75 psittacosaur individuals have been recovered, including nearly 20 complete skeletons with skulls (Lucas, 2006). Although there are up to fourteen named species, some paleontologists such as Zhae et al. (2006) believe taxonomic revision of the psittacosaur genus is overdue and it is probable …show more content…
Evidence which supports this is that they had self-sharpening teeth, appearing to have been useful for slicing tough plant material. While their teeth were sharp enough to slice, they were not capable of grinding or chewing food efficiently, unlike their later ceratopsian decendents. In place of chewing the plant material, they used gastroliths which would wear down food as it passed through the digestive system. There have been cases in which more than fifty gastroliths are found in the abdominal cavities of psittacosaurs, and may have been stored in a gizzard, as in modern birds (Peter and You,