Two subclasses of cestodes are differentiated on the basis of the numbers of larval hooks, the Cestodaria being decacanth (10 hooks) and the Eucestoda being hexacanth (6 hooks). Collectively, 14 orders of cestodes have been identified according to differences in parasite morphology and developmental cycles.
Most meteorites originate between Mars and Jupiter, where a belt of asteroids has lingered for 4.5 billion years, since the solar system was young. No rock on Earth is as old as a meteoriteâall terrestrial material has been ground, melted, and reformed by plate tectonics. Meteorites have other, less common, origins. Meteor impacts on the moon or Mars can eject surface material into space that ends up on Earth. Last year a 10.5-ounce meteorite that originated on Mars fetched $94,000. A 4-pound lunar meteorite, the most expensive ever auctioned, sold for $330,000 in 2012.
Nearly all meteorites are found in deserts (yes, Antarctica is a desert because the annual precipitation rate is very low). Deserts are places that collect meteorites over thousands of years and nothing much happens to the meteorite.any meteorites have been found in the Sahara Desert of northern Africa, mainly by private collectors. More meteorites have been found in Oman, a desert country about the size of New Mexico, than in all of North America (Canada, Mexico, U.S.).