英文字典中文字典


英文字典中文字典51ZiDian.com



中文字典辞典   英文字典 a   b   c   d   e   f   g   h   i   j   k   l   m   n   o   p   q   r   s   t   u   v   w   x   y   z       







请输入英文单字，中文词皆可：

安装中文字典英文字典查询工具!


中文字典英文字典工具:
选择颜色:
输入中英文单字

































































英文字典中文字典相关资料:


  • What is an ammonite? - Natural History Museum
    Ammonites were shelled cephalopods that died out about 66 million years ago Discover when they lived, why they went extinct, why they're important to science, and much more
  • Ammonoidea - Wikipedia
    Their fossil shells usually take the form of planispirals, although some helically spiraled and nonspiraled forms (known as heteromorphs) have been found, primarily during the Cretaceous period Because ammonites and their close relatives are extinct, little is known about their way of life
  • Ammonites – Fossil Cephalopods, Evolution, and Geological Significance
    Ammonites are extinct marine mollusks that lived from the Devonian to the end of the Cretaceous Period, roughly 400 to 66 million years ago They are among the most important index fossils, helping geologists to date and correlate sedimentary rock layers across continents
  • The Intriguing World of Ammonite Fossils! - Rock Seeker
    Ammonite fossils are the remains of an extinct group of marine animals known as ammonites These creatures were once the most abundant animals of the ancient seas and are now a popular subject of study among paleontologists
  • Ammonites: What Is An Ammonite? - FossilEra. com
    Ammonites were extinct, predatory marine mollusks that thrived in Earth’s oceans for more than 170 million years These animals were cephalopods—relatives of modern octopus, squid, and cuttlefish—and possessed well-developed eyes, multiple tentacles, and a coiled external shell
  • Ammonites, facts and photos | National Geographic
    Ammonite shells are used today as index fossils, meaning they can help date other fossils that are found in the same layer of marine rock
  • Where Are the Ammonites Today and Why Did They Disappear?
    Ammonite fossils are particularly common in rocks from the Jurassic and Cretaceous periods, the eras when they were most abundant Their widespread presence and rapid evolution make them “index fossils,” allowing geologists to accurately date rock layers and understand ancient marine environments
  • Ammonite - Prehistoric 101
    Ammonites hold significant cultural and scientific importance as fossils and symbols of Earth’s ancient history Throughout human history, these spiral-shaped shells have fascinated people across cultures and civilizations, inspiring myths, artwork, and scientific curiosity
  • Ammonites - British Geological Survey
    Ammonites were marine animals belonging to the phylum Mollusca and the class Cephalopoda They had a coiled external shell similar to that of the modern nautilus
  • 35 Facts About Ammonite Fossil
    Ammonite fossils are the remains of ancient marine mollusks that lived in the seas between 240 - 65 million years ago These creatures are related to today's octopuses, squid, and cuttlefish





中文字典-英文字典  2005-2009