Hom fossil yog ib qho ammonite?
Hom fossil yog ib qho ammonite?

Video: Hom fossil yog ib qho ammonite?

Video: Hom fossil yog ib qho ammonite?
Video: How an ammonite becomes a fossil 2024, Kaum ib hlis
Anonim

Ammonites yog kab tias cov pob txha paub ntau tshaj plaws, muaj cov kab uas feem ntau ribbed kauv-daim plhaub raws li daim duab saum toj no. Cov tsiaj no nyob hauv hiav txwv ntawm 240 - 65 lab xyoo dhau los, thaum lawv tau ploj mus nrog rau dinosaurs.

Dhau li ntawm no, puas yog ammonite fossils tsawg?

Anaptychi kuj yog tsis tshua muaj raws li pob txha . Lawv pom sawv cev ammonites los ntawm lub sij hawm Devonian mus rau lub sij hawm Cretaceous. Calcified aptychi tsuas yog tshwm sim hauv ammonites los ntawm Mesozoic era. Lawv yuav luag ib txwm pom cais tawm ntawm lub plhaub, thiab tsuas yog heev tsis tshua muaj khaws cia rau hauv qhov chaw.

Ib sab saum toj, dab tsi yog ammonite plhaub ua los ntawm? Tsuas yog rau sab hauv-feem ntau whorl, lub plhaub yog ua nce ntawm peb txheej. Cov innermost thiab outermost txheej yog nyias muaj li ntawm prisms ntawm aragonite (ib daim ntawv ntawm calcium carbonate). Lub thicker nruab nrab txheej yog nacreous (niam-ntawm-pearl), tsim ntawm me me tabular crystals ntawm aragonite.

Ib sab saum toj no, ua li cas ammonite fossils tsim?

Lawv yog feem ntau pom li pob txha , tsim thaum cov seem los yog kab ntawm cov tsiaj tau faus rau hauv cov av xuab zeb uas tom qab ntawd solidified rau hauv pob zeb. Ammonites yog cov tsiaj hauv hiav txwv thiab muaj lub plhaub sab nraud zoo ib yam li niaj hnub pearly nautilus.

Muaj pes tsawg ammonite fossils?

Fossil Cov ntaub ntawv Ammonites yog cov yug me nyuam loj hlob, nyob hauv tsev kawm ntawv, thiab muaj ntau tshaj plaws pob txha pom hnub no. Lawv tau ploj mus nrog cov dinosaurs 65 lab xyoo dhau los. Cov kws tshawb fawb siv ntau yam duab thiab qhov ntau thiab tsawg ammonite shells uas tshwm sim thiab ploj mus dhau lub hnub nyoog mus rau lwm yam pob txha.

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