index fossil การใช้

• It has a cosmopolitan distribution and is an important index fossil in biostratigraphy.
• It is an important index fossil in biostratigraphy.
• Important index fossils for the Cenomanian are the ammonites " Mantelliceras mantelli ".
• Many ecphora species are important index fossils.
• The family includes several important index fossils.
• They have been recorded from every continent and many are used as zonal or index fossils.
• It has become especially useful to metamorphic and igneous geologists where index fossils are seldom available.
• Other index fossils from Coon Creek date a little older than 70.6 million years.
• They lived during the Jurassic Period and serve as an index fossil for that time period.
• "Phyllograptus " species are excellent index fossils or guide fossils for identifying Ordovician rocks.
• Geologists employ biostratigraphy, the use of index fossils, for dating sedimentary rock units like the Coon Creek.
• Found in the late Ludlow-aged Kuanti Formation, the remains were dated using conodonts as index fossils.
• With Garretson's help, Grabau went on to write papers about his findings on North American index fossils.
• Since there are no index fossils, the sedimentary rocks cannot be dated using fossils, like they can in Phanerozoic rocks.
• Other important groups that provide index fossils are the corals, graptolites, brachiopods, trilobites, and echinoids ( sea urchins ).
• They are excellent candidates for index fossils used for dating rock formations in the Paleozoic Era and when other fossils are not available.
• Since their armoured plates are often preserved and are abundant in certain localities, aetosaurs serve as important Late Triassic tetrapod index fossils.
• It is known from abundant fossils representing sixteen species, which serve as important index fossil used to date geologic formations in China.
• Their fossils are scientifically significant as many are now used as index fossils or were completely unknown to science before their discovery here.
• The only song from " Suffer " that has never been performed live is " Part IV ( The Index Fossil ) ".