{"id":1904,"date":"2026-09-10T15:07:06","date_gmt":"2026-09-10T21:07:06","guid":{"rendered":"https:\/\/elcontemporaneo.mx\/?p=1904"},"modified":"2026-09-10T15:07:06","modified_gmt":"2026-09-10T21:07:06","slug":"reptiles-pez","status":"publish","type":"post","link":"https:\/\/elcontemporaneo.mx\/index.php\/2026\/09\/10\/reptiles-pez\/","title":{"rendered":"Reptiles pez"},"content":{"rendered":"<p><span style=\"font-weight: 400;\">Uno de los linajes de di\u00e1psidos que sobrevivi\u00f3 la gran extinci\u00f3n del P\u00e9rmico se adapt\u00f3 de nuevo por completo a la vida acu\u00e1tica que sus ancestros tetr\u00e1podos tanto se esforzaron por dejar.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">El problema es que la evoluci\u00f3n no funciona en reversa. Para volver al agua tuvieron que desarrollar nuevas adaptaciones. Los ictiosauromorfos se caracterizaron por un hocico alargado con las fosas nasales cercanas a los ojos, un cuerpo largo y ahusado (similar al de los tiburones), las extremidades palmeadas y en los grupos de ictiosaurios m\u00e1s derivados del Tri\u00e1sico tard\u00edo y el Jur\u00e1sico, la presencia de aletas pectorales, dorsal y caudal copiando el dise\u00f1o m\u00e1s hidrodin\u00e1mico posible de la naturaleza: la de un pez (eso significa el nombre, por cierto, &#8220;reptiles pez&#8221;).<\/span><\/p>\n<p><span style=\"font-weight: 400;\">A pesar que iniciaron con tallas peque\u00f1as (como casi todos los grupos lo hacen) los ictiosauromorfos y su estirpe desarrollaron especies gigantes como Shastasaurus y Shonisaurus que superaban los 20 metros de largo. Aun as\u00ed, el promedio del grupo va de los 2 a los 4 m de longitud.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Los ictiosaurios respiraban aire como todos los dem\u00e1s saur\u00f3psidos y sus cr\u00edas nac\u00edan de huevo; el cambio en su morfolog\u00eda hizo imposible que estos animales pudieran salir a tierra firme a reproducirse, como hacen las tortugas marinas.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400;\">La estrategia que se adapt\u00f3 a su nueva forma de vida fue el \u201covoviviparismo\u201d. La hembra se queda con los huevos fertilizados dentro de su cuerpo y cuando las cr\u00edas eclosionan, entonces las dan a luz. Algunos animales actuales todav\u00eda usan esta estrategia, como las v\u00edboras (quienes no est\u00e1n cercanamente emparentadas con los ictiosaurios).<\/span><\/p>\n<p><span style=\"font-weight: 400;\">A pesar\u00a0 que los ictiosaurios son reconocidas criaturas del Mesozoico, tambi\u00e9n conocida como &#8220;La Era de los Dinosaurios\u201d no son dinosaurios.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">El grupo de los reptiles pez declin\u00f3 hacia mediados del Cret\u00e1cico y se extingui\u00f3 por completo a finales del Cenomaniano en lo que se denomin\u00f3 \u201cevento Bonarelli\u201d, donde un aparente cambio clim\u00e1tico provoc\u00f3 una reducci\u00f3n de la concentraci\u00f3n de ox\u00edgeno en los oc\u00e9anos, lo que afect\u00f3 a varios grupos de organismos marinos.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Uno de los linajes de di\u00e1psidos que sobrevivi\u00f3 la gran extinci\u00f3n del P\u00e9rmico se adapt\u00f3 de nuevo por completo a la vida acu\u00e1tica que sus ancestros tetr\u00e1podos tanto se esforzaron por dejar. El problema es que la evoluci\u00f3n no funciona en reversa. Para volver al agua tuvieron que desarrollar nuevas adaptaciones. Los ictiosauromorfos se caracterizaron [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[13],"tags":[],"columnista":[17],"class_list":["post-1904","post","type-post","status-publish","format-standard","hentry","category-columnas","columnista-dinodatos"],"_links":{"self":[{"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/posts\/1904","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/comments?post=1904"}],"version-history":[{"count":1,"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/posts\/1904\/revisions"}],"predecessor-version":[{"id":1905,"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/posts\/1904\/revisions\/1905"}],"wp:attachment":[{"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/media?parent=1904"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/categories?post=1904"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/tags?post=1904"},{"taxonomy":"columnista","embeddable":true,"href":"https:\/\/elcontemporaneo.mx\/index.php\/wp-json\/wp\/v2\/columnista?post=1904"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}