{"id":16998,"date":"2023-09-30T16:58:42","date_gmt":"2023-09-30T16:58:42","guid":{"rendered":"https:\/\/www.lifescienceart.com\/?p=16998"},"modified":"2023-09-30T16:58:42","modified_gmt":"2023-09-30T16:58:42","slug":"earth-oldest-ocean-giant-ichthyosaurs","status":"publish","type":"post","link":"https:\/\/www.lifescienceart.com\/cs\/science\/paleontology\/earth-oldest-ocean-giant-ichthyosaurs\/","title":{"rendered":"Nejv\u011bt\u0161\u00ed mo\u0159sk\u00fd obr Zem\u011b: Z\u00e1hada ichtyosaur\u016f"},"content":{"rendered":"

Nejv\u011bt\u0161\u00ed mo\u0159sk\u00fd obr Zem\u011b: Z\u00e1hada ichtyosaur\u016f<\/h2>\n\n

Objev triasov\u00e9ho obra<\/h2>\n\n

Ve fos\u00edliemi bohat\u00fdch hor\u00e1ch Nevady v\u011bdci u\u010dinili mimo\u0159\u00e1dn\u00fd objev: dvouap\u016flmetrovou lebku pat\u0159\u00edc\u00ed kolos\u00e1ln\u00edmu mo\u0159sk\u00e9mu plazu, kter\u00fd se potuloval v prav\u011bk\u00fdch oce\u00e1nech p\u0159ed 246 miliony let. Tento nov\u00fd druh, nazvan\u00fd Cymbospondylus youngorum, p\u0159edstavuje nejv\u011bt\u0161\u00ed fos\u00edlii z triasov\u00e9ho obdob\u00ed, jak\u00e1 kdy byla nalezena.<\/p>\n\n

Ichtyosau\u0159i: Ob\u0159i mezozoick\u00fdch mo\u0159\u00ed<\/h2>\n\n

Ichtyosau\u0159i byli mo\u0159\u0161t\u00ed plazi, kte\u0159\u00ed dominovali oce\u00e1n\u016fm v pr\u016fb\u011bhu mesozoick\u00e9 \u00e9ry po boku sv\u00fdch suchozemsk\u00fdch prot\u011bj\u0161k\u016f, dinosaur\u016f. Tito z\u00e1hadn\u00ed tvorov\u00e9 se vyvinuli z p\u0159edk\u016f \u017eij\u00edc\u00edch na sou\u0161i a p\u0159e\u0161li na zcela vodn\u00ed zp\u016fsob \u017eivota, \u010d\u00edm\u017e se stali prvn\u00edmi zn\u00e1m\u00fdmi obry planety. Mohli dor\u016fst obrovsk\u00fdch rozm\u011br\u016f a soupe\u0159it s dne\u0161n\u00edmi vorvani.<\/p>\n\n

Evolu\u010dn\u00ed z\u00e1zrak: Rychl\u00fd r\u016fst k gigantismu<\/h2>\n\n

Jedn\u00edm z nejv\u00edce fascinuj\u00edc\u00edch aspekt\u016f ichtyosaur\u016f je ohromuj\u00edc\u00ed rychlost, s jakou vyvinuli svou gigantickou velikost t\u011bla. Pot\u00e9, co se jejich p\u0159edci vydali do mo\u0159e, trvalo ichtyosaur\u016fm pouh\u00e9 t\u0159i miliony let, ne\u017e dos\u00e1hli sv\u00fdch obrovsk\u00fdch rozm\u011br\u016f. Tento evolu\u010dn\u00ed v\u00fdkon stoj\u00ed v ostr\u00e9m kontrastu s velrybami, kter\u00e9 pot\u0159ebovaly 45 milion\u016f let, aby dos\u00e1hly podobn\u00e9 velikosti.<\/p>\n\n

Dynamika potravn\u00edho \u0159et\u011bzce a r\u016fst ichtyosaur\u016f<\/h2>\n\n

Aby v\u011bdci pochopili rychl\u00fd r\u016fst ichtyosaur\u016f, zrekonstruovali potravn\u00ed s\u00ed\u0165 triasov\u00fdch oce\u00e1n\u016f. Asi p\u0159ed 252 miliony let vyhynut\u00ed na konci permu vymazalo 96 % mo\u0159sk\u00fdch druh\u016f a vytvo\u0159ilo ekologickou pr\u00e1zdnotu. Tuto pr\u00e1zdnotu zaplnili amoniti, druh m\u011bkk\u00fd\u0161e, a \u00faho\u0159ovit\u00ed tvorov\u00e9 zvan\u00ed konodonti.<\/p>\n\n

Na rozd\u00edl od dne\u0161n\u00edch velryb, kter\u00e9 filtruj\u00ed potravu z mal\u00fdch organism\u016f, nem\u011bli ichtyosau\u0159i p\u0159\u00edstup k planktonu jako zdroji potravy. M\u00edsto toho lovili tvory, kte\u0159\u00ed konzumovali amonity, jako jsou ryby a olihn\u011b. Tato jedine\u010dn\u00e1 potravn\u00ed s\u00ed\u0165 poskytovala ichtyosaur\u016fm bohat\u00fd a hojn\u00fd zdroj potravy, co\u017e potenci\u00e1ln\u011b p\u0159isp\u00edvalo k jejich rychl\u00e9mu r\u016fstu.<\/p>\n\n

Poznatky z triasov\u00e9ho potravn\u00edho \u0159et\u011bzce<\/h2>\n\n

Objev Cymbospondylus youngorum a anal\u00fdza triasov\u00e9 potravn\u00ed s\u00edt\u011b poskytuj\u00ed cenn\u00e9 poznatky o evoluci velikosti t\u011bla u mo\u0159sk\u00fdch plaz\u016f. Prozkoum\u00e1n\u00edm ekologick\u00e9 dynamiky starov\u011bk\u00fdch oce\u00e1n\u016f mohou v\u011bdci l\u00e9pe porozum\u011bt faktor\u016fm, kter\u00e9 formovaly r\u016fst a diverzifikaci t\u011bchto velkolep\u00fdch tvor\u016f.<\/p>\n\n

Podobnosti a rozd\u00edly s velrybami<\/h2>\n\n

A\u010dkoli ichtyosau\u0159i a velryby sd\u00edlej\u00ed n\u00e1padn\u00e9 podobnosti ve velikosti a tvaru t\u011bla, jejich evolu\u010dn\u00ed cesty se v\u00fdrazn\u011b li\u0161ily. Ob\u011b skupiny poch\u00e1zej\u00ed od suchozemsk\u00fdch p\u0159edk\u016f, ale ichtyosau\u0159i se vyv\u00edjeli mnohem rychleji ne\u017e velryby. Nav\u00edc se ichtyosau\u0159i ne\u017eivili filtrac\u00ed jako velryby, ale spol\u00e9hali se na jinou potravn\u00ed s\u00ed\u0165.<\/p>\n\n

Odhalov\u00e1n\u00ed tajemstv\u00ed evoluce ichtyosaur\u016f<\/h2>\n\n

Objev Cymbospondylus youngorum vyvol\u00e1v\u00e1 nov\u00e9 ot\u00e1zky o evoluci ichtyosaur\u016f. Jak se t\u011bmto mo\u0159sk\u00fdm plaz\u016fm poda\u0159ilo dos\u00e1hnout tak rychl\u00e9ho r\u016fstu? Jak\u00e9 dal\u0161\u00ed faktory p\u0159isp\u011bly k jejich \u00fasp\u011bchu v triasov\u00fdch oce\u00e1nech? Pokra\u010duj\u00edc\u00edm studiem t\u011bchto d\u00e1vn\u00fdch obr\u016f doufaj\u00ed v\u011bdci, \u017ee odhal\u00ed tajemstv\u00ed, kter\u00e1 obklopuj\u00ed jejich mimo\u0159\u00e1dn\u00e9 adaptace a evolu\u010dn\u00ed historii.<\/p>","protected":false},"excerpt":{"rendered":"

Nejv\u011bt\u0161\u00ed mo\u0159sk\u00fd obr Zem\u011b: Z\u00e1hada ichtyosaur\u016f Objev triasov\u00e9ho obra Ve fos\u00edliemi bohat\u00fdch hor\u00e1ch Nevady v\u011bdci u\u010dinili mimo\u0159\u00e1dn\u00fd objev: dvouap\u016flmetrovou lebku pat\u0159\u00edc\u00ed kolos\u00e1ln\u00edmu mo\u0159sk\u00e9mu plazu, kter\u00fd se potuloval v prav\u011bk\u00fdch oce\u00e1nech…<\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[138],"tags":[136,21053,5412,137,4939],"class_list":["post-16998","post","type-post","status-publish","format-standard","hentry","category-paleontology","tag-evolution","tag-ichthyosaurs","tag-marine-reptiles","tag-paleontology","tag-triassic-period"],"_links":{"self":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/16998","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/comments?post=16998"}],"version-history":[{"count":1,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/16998\/revisions"}],"predecessor-version":[{"id":16999,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/16998\/revisions\/16999"}],"wp:attachment":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/media?parent=16998"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/categories?post=16998"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/tags?post=16998"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}