V roce 1947 objevil paleontolog C. C. Young fragment fosilizovan\u00e9 lebky pobl\u00ed\u017e Lufengu v \u010c\u00edn\u011b. Zpo\u010d\u00e1tku se domn\u00edval, \u017ee pat\u0159\u00ed dlouhokrc\u00edmu dinosaurovi Lufengosaurovi. O n\u011bkolik let pozd\u011bji jej v\u0161ak p\u0159eklasifikoval na fytosaura, starov\u011bk\u00e9ho archosaura, kter\u00fd se podobal krokod\u00fdl\u016fm.<\/p>\n\n
Fosilie z\u016fstala d\u016fle\u017eit\u00fdm miln\u00edkem pro fytosaury, proto\u017ee nazna\u010dovala jejich p\u0159e\u017eit\u00ed miliony let pot\u00e9, co vymizeli jinde. Ne v\u0161ichni paleontologov\u00e9 v\u0161ak s Youngovou identifikac\u00ed souhlasili. N\u011bkte\u0159\u00ed tvrdili, \u017ee fragment je p\u0159\u00edli\u0161 po\u0161kozen\u00fd, aby bylo mo\u017en\u00e9 ur\u010dit jeho p\u0159esnou klasifikaci.<\/p>\n\n
V posledn\u00edch letech paleontologov\u00e9 Paul Barrett a Xu Xing znovu prozkoumali fosilii Pachysucha. Zjistili, \u017ee postr\u00e1d\u00e1 kl\u00ed\u010dov\u00e9 vlastnosti fytosaur\u016f, jako jsou nosn\u00ed otvory daleko vzadu na \u010denichu. M\u00edsto toho vykazoval \u010detn\u00e9 znaky, kter\u00e9 odpov\u00eddaly znak\u016fm sauropodomorfn\u00edch dinosaur\u016f.<\/p>\n\n
Barrett a Xu dosp\u011bli k z\u00e1v\u011bru, \u017ee Pachysuchus nebyl fytosaurus, ale sauropodomorfn\u00ed dinosaurus. Sauropodomorfov\u00e9 byli r\u016fznorodou skupinou dinosaur\u016f, kter\u00e1 zahrnovala dlouhokrc\u00e9 obry, jako byl Brachiosaurus. Fragment \u010delisti Pachysucha je p\u0159\u00edli\u0161 po\u0161kozen\u00fd, aby bylo mo\u017en\u00e9 ur\u010dit p\u0159esn\u00fd druh dinosaura, ke kter\u00e9mu pat\u0159il, ale pravd\u011bpodobn\u011b p\u0159edstavuje d\u0159\u00edve nezn\u00e1mou varietu sauropodomorfa.<\/p>\n\n
Reklasifikace Pachysucha jako dinosaura m\u00e1 d\u016fsledky pro na\u0161e ch\u00e1p\u00e1n\u00ed koexistence dinosaur\u016f a fytosaur\u016f. O fytosaurech, kte\u0159\u00ed \u017eili po boku ran\u00fdch dinosaur\u016f a lovili je, se v\u011b\u0159ilo, \u017ee vyhynuli na konci triasu. Av\u0161ak navrhovan\u00e9 v\u00fdskyty jursk\u00fdch fytosaur\u016f v Asii byly velmi pochybn\u00e9.<\/p>\n\n
Nep\u0159\u00edtomnost jursk\u00fdch fytosaur\u016f v Asii nazna\u010duje, \u017ee tito tvorov\u00e9 mohli b\u00fdt vyhubeni d\u0159\u00edve, ne\u017e se d\u0159\u00edve myslelo. To podporuje hypot\u00e9zu, \u017ee dinosau\u0159i dos\u00e1hli glob\u00e1ln\u00ed dominance po vyhynut\u00ed fytosaur\u016f a dal\u0161\u00edch velk\u00fdch archosau\u0159\u00edch pred\u00e1tor\u016f.<\/p>\n\n
Reklasifikace Pachysucha poskytuje nov\u00e9 poznatky o evoluci dinosaur\u016f. Nazna\u010duje, \u017ee rozmanitost sauropodomorfn\u00edch dinosaur\u016f mohla b\u00fdt v\u011bt\u0161\u00ed, ne\u017e se d\u0159\u00edve p\u0159edpokl\u00e1dalo. Nav\u00edc vyvol\u00e1v\u00e1 ot\u00e1zky ohledn\u011b konkuren\u010dn\u00edch interakc\u00ed mezi dinosaury a dal\u0161\u00edmi archosaury v ran\u00e9m obdob\u00ed jury.<\/p>\n\n
Abychom pln\u011b pochopili d\u016fsledky reklasifikace Pachysucha, je t\u0159eba dal\u0161\u00edho v\u00fdzkumu. Paleontologov\u00e9 pokra\u010duj\u00ed ve studiu fosiln\u00edho z\u00e1znamu a prov\u00e1d\u011bj\u00ed fylogenetick\u00e9 anal\u00fdzy, aby ur\u010dili p\u0159esn\u00e9 vztahy mezi Pachysuchem a dal\u0161\u00edmi dinosaury. Toto \u00fasil\u00ed pom\u016f\u017ee objasnit slo\u017eitou evolu\u010dn\u00ed historii t\u011bchto starov\u011bk\u00fdch tvor\u016f.<\/p>","protected":false},"excerpt":{"rendered":"
Pachysuchus: Skryt\u00fd dinosaurus znovuobjeven Reklasifikace z\u00e1hadn\u00e9ho fragmentu \u010delisti V roce 1947 objevil paleontolog C. C. Young fragment fosilizovan\u00e9 lebky pobl\u00ed\u017e Lufengu v \u010c\u00edn\u011b. Zpo\u010d\u00e1tku se domn\u00edval, \u017ee pat\u0159\u00ed dlouhokrc\u00edmu dinosaurovi…<\/p>\n","protected":false},"author":1,"featured_media":23920,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1011],"tags":[2704,20292,137,20293,941],"class_list":["post-15218","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-paleontology-and-evolution","tag-dinosaur","tag-pachysuchus","tag-paleontology","tag-phytosaur","tag-sauropodomorph"],"_links":{"self":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/15218","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\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/comments?post=15218"}],"version-history":[{"count":1,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/15218\/revisions"}],"predecessor-version":[{"id":15219,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/posts\/15218\/revisions\/15219"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/media\/23920"}],"wp:attachment":[{"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/media?parent=15218"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/categories?post=15218"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lifescienceart.com\/cs\/wp-json\/wp\/v2\/tags?post=15218"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}