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.
A meteorite is a rock found on the surface of the planet that has come from space. In space they are called meteoroids, when seen burning in our atmosphere as shooting stars they are called meteors and when found as rocks on the surface, having survived the journey through our atmosphere, they are called meteorites. meteorite is a rock that fell from space and survived the heat and pressure of falling through the atmosphere and landed on Earth. When it was a streak of light in the sky, it was a meteor.