Psittacosaurus is a genus of psittacosaurid ceratopsian dinosaur from the Early Cretaceous Period of what is now Asia, about 130 to 100Â million years ago. It is notable for being the most species-rich dinosaur genus. Nine to eleven species are recognized from fossils found in different regions of modern-day China, Mongolia and Russia, with a possible additional species from Thailand. All species of Psittacosaurus were gazelle-sized bipedal herbivores characterized by a high, powerful beak on the upper jaw. At least one species had long, quill-like structures on its tail and lower back, possibly serving a display function. Psittacosaurus is not as familiar to the general public as its distant relative Triceratops but it is one of the most completely known dinosaur genera. Fossils of over 400 individuals have been collected so far, including many complete skeletons. Most different age classes are represented, from hatchling through to adult, which has allowed several detailed studies of Psittacosaurus growth rates and reproductive biology. The abundance of this dinosaur in the fossil record has led to its use as an index fossil for Early Cretaceous sediments of central Asia.
Read more: https://en.wikipedia.org/wiki/Psittacosaurus
_______________________________ Today's selected anniversaries:
1558:
Francis, Duke of Guise (pictured), retook Calais, England's last continental possession, for France. https://en.wikipedia.org/wiki/Calais
1785:
Frenchman Jean-Pierre Blanchard and American John Jeffries became the first to cross the English Channel by air, in a balloon. https://en.wikipedia.org/wiki/English_Channel
1948:
Air National Guard pilot Thomas Mantell fatally crashed his P-51 Mustang while in pursuit of a UFO near Fort Knox, Kentucky. https://en.wikipedia.org/wiki/Mantell_UFO_incident
1993:
The Fourth Republic of Ghana was inaugurated with Jerry Rawlings as its president. https://en.wikipedia.org/wiki/History_of_Ghana
2007:
Newly appointed Archbishop of Warsaw Stanisław Wielgus resigned amid allegations that he collaborated with the Polish communist government's secret police. https://en.wikipedia.org/wiki/Stanis%C5%82aw_Wielgus
_____________________________ Wiktionary's word of the day:
burgess: 1. An inhabitant of a borough with full rights; a citizen. 2. (historical) A town magistrate. https://en.wiktionary.org/wiki/burgess
___________________________ Wikiquote quote of the day:
The whole country is full of enterprise. Our common schools are diffusing intelligence among the people and our industry is fast accumulating the comforts and luxuries of life. ... It is not strange, however much it may be regretted, that such an exuberance of enterprise should cause some individuals to mistake change for progress and the invasion of the rights of others for national prowess and glory. --Millard Fillmore https://en.wikiquote.org/wiki/Millard_Fillmore