{"id":4199,"date":"2021-06-14T09:28:20","date_gmt":"2021-06-14T09:28:20","guid":{"rendered":"https:\/\/www.lifescienceart.com\/?p=4199"},"modified":"2021-06-14T09:28:20","modified_gmt":"2021-06-14T09:28:20","slug":"the-enigmatic-giants-how-sauropods-became-the-largest-land-animals","status":"publish","type":"post","link":"https:\/\/www.lifescienceart.com\/cs\/science\/paleontology\/the-enigmatic-giants-how-sauropods-became-the-largest-land-animals\/","title":{"rendered":"Z\u00e1hadn\u00ed ob\u0159i: H\u00e1danka velikosti sauropod\u016f"},"content":{"rendered":"

Z\u00e1hadn\u00ed ob\u0159i: Jak se sauropodi stali nejv\u011bt\u0161\u00edmi suchozemsk\u00fdmi zv\u00ed\u0159aty<\/h2>\n\n

H\u00e1danka velikosti sauropod\u016f<\/h2>\n\n

Sauropodi, dlouhokrc\u00ed, zemi ot\u0159\u00e1saj\u00edc\u00ed dinosau\u0159i, byli nejv\u011bt\u0161\u00ed suchozemsk\u00e1 zv\u00ed\u0159ata, kter\u00e1 kdy kr\u00e1\u010dela po Zemi. N\u011bkte\u0159\u00ed, jako Argentinosaurus a Supersaurus, m\u011b\u0159ili na d\u00e9lku p\u0159es 100 stop od hlavy k ocasu. Jak tito kolos\u00e1ln\u00ed tvorov\u00e9 dos\u00e1hli tak obrovsk\u00fdch rozm\u011br\u016f? Tato ot\u00e1zka dlouhodob\u011b mate paleontology.<\/p>\n\n

Pl\u00e1n t\u011bla a adaptace<\/h2>\n\n

Sauropodi m\u011bli charakteristick\u00fd pl\u00e1n t\u011bla, pro kter\u00fd byla typick\u00e1 mal\u00e1 hlava, dlouh\u00fd krk, objemn\u00e9 t\u011blo podep\u00edran\u00e9 sloupovit\u00fdma nohama a dlouh\u00fd ocas. A\u010dkoli vykazovali r\u016fzn\u00e9 adaptace, jako nap\u0159. vysava\u010d-jako hlavu Nigersaura a dvojitou kr\u010dn\u00ed plachtu Amargasaura, tyto variace podstatn\u011b nem\u011bnily z\u00e1kladn\u00ed tvar t\u011bla sauropod\u016f.<\/p>\n\n

Tenk\u00fd p\u0159edn\u00ed konec<\/h2>\n\n

Mal\u00e9 hlavy sauropod\u016f byly nezbytnost\u00ed. Velk\u00e1 hlava by byla obt\u00ed\u017en\u011b zvedateln\u00e1 a kontrolovateln\u00e1, zvl\u00e1\u0161t\u011b s v\u00e1hou dlouh\u00e9ho krku. Tato adaptace umo\u017enila sauropod\u016fm udr\u017eet si rovnov\u00e1hu a pohyblivost.<\/p>\n\n

Strategie krmen\u00ed<\/h2>\n\n

Navzdory sv\u00fdm drobn\u00fdm hlav\u00e1m pot\u0159ebovali sauropodi obrovsk\u00e1 mno\u017estv\u00ed potravy, aby u\u017eivili sv\u00e1 masivn\u00ed t\u011bla. Jejich zuby, p\u0159ipom\u00ednaj\u00edc\u00ed kol\u00edky nebo tu\u017eky, byly omezeny na p\u0159edn\u00ed \u010d\u00e1st jejich \u010delist\u00ed. Na rozd\u00edl od b\u00fdlo\u017erav\u00fdch dinosaur\u016f jako ceratopsov\u00e9 a hadrosau\u0159i s \u0159adami drtiv\u00fdch zub\u016f postr\u00e1dali sauropodi zubn\u00ed apar\u00e1t pro d\u016fkladn\u00e9 \u017ev\u00fdk\u00e1n\u00ed.<\/p>\n\n

M\u00edsto toho sauropodi pravd\u011bpodobn\u011b polykali svou potravu celou a spol\u00e9hali na sv\u016fj tr\u00e1vic\u00ed syst\u00e9m, aby ji rozlo\u017eil. Gastrolithy, tj. spolknut\u00e9 kameny, p\u016fsobily jako n\u00e1hradn\u00ed zuby v jejich tr\u00e1vic\u00edch traktech a drtily potravu, kdy\u017e j\u00ed proch\u00e1zela. P\u0159\u00edtomnost gastrolith\u016f ve spojen\u00ed se sauropod\u00edmi kostrami tuto hypot\u00e9zu podporuje.<\/p>\n\n

Adaptace tr\u00e1ven\u00ed<\/h2>\n\n

A\u010dkoli se jejich \u017ealudky nedochovaly, p\u0159edpokl\u00e1d\u00e1 se, \u017ee sauropodi m\u011bli specializovan\u00e9 tr\u00e1vic\u00ed komory podobn\u00e9 t\u011bm, kter\u00e9 se nach\u00e1zej\u00ed u dne\u0161n\u00edch krav. Tento v\u00edcekomorov\u00fd syst\u00e9m jim umo\u017e\u0148oval z\u00edskat maximum \u017eivin z potravy a p\u0159esunout se k nov\u00fdm zdroj\u016fm vegetace, ani\u017e by tr\u00e1vili p\u0159\u00edli\u0161 mnoho \u010dasu \u017ev\u00fdk\u00e1n\u00edm.<\/p>\n\n

\u0158e\u0161en\u00ed probl\u00e9m\u016f s teplem a okysli\u010dov\u00e1n\u00edm<\/h2>\n\n

Obrovsk\u00e1 velikost sauropod\u016f p\u0159edstavovala v\u00fdzvy v regulaci t\u011blesn\u00e9ho tepla a okysli\u010dov\u00e1n\u00ed jejich plic. Aby tyto probl\u00e9my vy\u0159e\u0161ili, mohli sauropodi vyu\u017e\u00edvat syst\u00e9m vzdu\u0161n\u00fdch vak\u016f ve sv\u00fdch t\u011blech, zejm\u00e9na ve sv\u00fdch obratlech. Tyto vzdu\u0161n\u00e9 vaky, sd\u00edlen\u00e9 s teropodn\u00edmi dinosaury jako Aerosteon a pt\u00e1ky, vznikaly v plic\u00edch a roz\u0161i\u0159ovaly se do kost\u00ed, co\u017e sni\u017eovalo hmotnost kostry a z\u00e1rove\u0148 udr\u017eovalo jej\u00ed pevnost.<\/p>\n\n

Krom\u011b toho mohly vzdu\u0161n\u00e9 vaky napom\u00e1hat termoregulaci a efektivit\u011b d\u00fdch\u00e1n\u00ed. V\u00fdm\u011bnou tepla s okoln\u00edm vzduchem pomohly vzdu\u0161n\u00e9 vaky sauropod\u016fm udr\u017eet stabiln\u00ed t\u011blesnou teplotu. Zv\u011bt\u0161en\u00fd povrch pro v\u00fdm\u011bnu kysl\u00edku uvnit\u0159 vzdu\u0161n\u00fdch vak\u016f tak\u00e9 zv\u00fd\u0161il jejich d\u00fdchac\u00ed kapacitu.<\/p>\n\n

Z\u00e1v\u011br<\/h2>\n\n

Evoluce sauropod\u016f v nejv\u011bt\u0161\u00ed suchozemsk\u00e1 zv\u00ed\u0159ata byla pozoruhodn\u00fdm po\u010dinem. P\u0159izp\u016fsoben\u00edm sv\u00e9ho t\u011blesn\u00e9ho pl\u00e1nu, strategi\u00ed krmen\u00ed a tr\u00e1vic\u00edch syst\u00e9m\u016f, aby p\u0159ekonali v\u00fdzvy sv\u00e9 obrovsk\u00e9 velikosti, tito kolos\u00e1ln\u00ed tvorov\u00e9 dominovali prav\u011bk\u00e9 krajin\u011b po miliony let. Jejich jedine\u010dn\u00e9 adaptace nad\u00e1le fascinuj\u00ed v\u011bdce a vzbuzuj\u00ed \u00fa\u017eas u v\u0161ech, kdo je potkaj\u00ed.<\/p>","protected":false},"excerpt":{"rendered":"

Z\u00e1hadn\u00ed ob\u0159i: Jak se sauropodi stali nejv\u011bt\u0161\u00edmi suchozemsk\u00fdmi zv\u00ed\u0159aty H\u00e1danka velikosti sauropod\u016f Sauropodi, dlouhokrc\u00ed, zemi ot\u0159\u00e1saj\u00edc\u00ed dinosau\u0159i, byli nejv\u011bt\u0161\u00ed suchozemsk\u00e1 zv\u00ed\u0159ata, kter\u00e1 kdy kr\u00e1\u010dela po Zemi. N\u011bkte\u0159\u00ed, jako Argentinosaurus a…<\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[138],"tags":[740,134,136,137,140,252,6390],"class_list":["post-4199","post","type-post","status-publish","format-standard","hentry","category-paleontology","tag-biology","tag-dinosaurs","tag-evolution","tag-paleontology","tag-prehistoric-animals","tag-nature","tag-sauropods"],"_links":{"self":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/4199","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=4199"}],"version-history":[{"count":1,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/4199\/revisions"}],"predecessor-version":[{"id":4200,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/4199\/revisions\/4200"}],"wp:attachment":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/media?parent=4199"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/categories?post=4199"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/tags?post=4199"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}