Crinoids yog cov pob txha muaj nyob hauv Silurian pob zeb ntawm Shropshire, cov pob zeb Carboniferous thaum ntxov ntawm Derbyshire thiab Yorkshire thiab cov pob zeb Jurassic ntawm Dorset thiab Yorkshire coasts.
pom crinoids nyob qhov twg?
Nyob deb ntawm cov pob txha crinoid feem ntau yog cov qia. Cov no muaj ntau nyob hauv sab hnub tuaj Kansas limestones thiab shales. Tsuas yog qee zaus yog lub khob zoo li calyx pom. Kansas, txawm li cas los xij, yog lub tsev rau qhov zoo nkauj thiab tsis tshua muaj pob txha pob txha hu ua Uintacrinus, uas tau khaws cia tag nrho.
Kuv yuav paub li cas yog tias kuv muaj crinoids?
Crinoids yog echinoderms ntsig txog cov ntses hnub qub, hiav txwv urchins, thiab cov hnub qub nkig. Zoo li lwm cov tswv cuab ntawm lawv cov phylum lawv yog cov tawv nqaij tawv, muaj tsib sab lossis pentaradial symmetry li cov neeg laus thiab cov calcium carbonate endoskeleton.
Puas tseem muaj crinoids?
kwv yees li 625 hom crinoids tseem muaj sia nyob niaj hnub no. Lawv yog cov xeeb leej xeeb ntxwv ntawm crinoids uas tau dim ntawm qhov kev ploj tuag ntawm qhov kawg ntawm Permian. Nws kwv yees tias ntau dua 6000 hom crinoids tau nyob hauv ntiaj teb.
Crinoids nyob qhov twg hauv dej hiav txwv?
Lawv nyob nyob rau hauv ob qho tib si hauv dej ntiav thiab hauv qhov tob li 9,000 meters (30,000 ft). Cov crinoids uas nyob rau hauv lawv cov neeg laus daim ntawv yog txuas mus rau lub hiav txwv hauv qab los ntawm ib tug stalk feem ntau hu ua hiav txwv lilies, thaum lub unstalked daim ntawv hu ua feather hnub qub los yog comatulids, yog cov tswv cuab ntawm cov loj tshaj plaws.kev txiav txim crinoid, Comatulida.
