{"id":382391,"date":"2026-04-09T01:53:11","date_gmt":"2026-04-09T01:53:11","guid":{"rendered":"https:\/\/www.newsbeep.com\/il\/382391\/"},"modified":"2026-04-09T01:53:11","modified_gmt":"2026-04-09T01:53:11","slug":"permian-fossil-is-earliest-evidence-of-rib-powered-breathing","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/il\/382391\/","title":{"rendered":"Permian Fossil is Earliest Evidence of Rib-Powered Breathing"},"content":{"rendered":"

Paleontologists have examined 289-million-year-old specimens of the early reptile Captorhinus aguti<\/a> that preserve a covering of three-dimensional skin, a complete shoulder girdle and ribcage with cartilages, and \u2014 most astonishingly \u2014 protein remnants that predate the previous oldest-known example by nearly 100 million years.<\/p>\n

\"Captorhinus<\/a><\/p>\n

Captorhinus aguti. Image credit: Michael DeBraga.<\/p>\n

The move from water to land was a major step in vertebrate evolution, and early amniotes<\/a> needed new ways of breathing to survive in dry environments.<\/p>\n

Earlier amniotes mainly relied on throat-based and skin-based respiration, whereas later amniotes used their ribs and chest to draw air into the lungs.<\/p>\n

Because soft tissues almost never fossilize, direct evidence of how and when this shift happened is lacking.<\/p>\n

\u201cCaptorhinus aguti is an interesting lizard-looking critter that is critical to understanding early amniote evolution,\u201d said Ethan Mooney, a Ph.D. candidate at Harvard University.<\/p>\n

\u201cThis creature, which grew over 5 cm in length, were among the earliest known reptiles to experiment with living on land. During their time, they were thriving and numerous.\u201d<\/p>\n

The three well-preserved specimens of Captorhinus aguti were discovered in unique cave systems near Richards Spur, Oklahoma.<\/p>\n

The fossils were encased in fine clay and saturated with oil, revealing previously unknown structures.<\/p>\n

In one specimen, the paleontologists identified a segmented cartilaginous sternum, sternal ribs, intermediate ribs, and structures connecting the ribcage to the shoulder girdle.<\/p>\n

For the first time in the fossil record, it was possible to view these structures in an early reptile and reconstruct the complete breathing apparatus of an early amniote.<\/p>\n

\u201cWe propose that the system found in Captorhinus aguti represents the ancestral condition for the kind of rib-assisted respiration present in living reptiles, birds, and mammals\u201d said Professor Robert R. Reisz, a paleontologist at the University of Toronto and Jilin University.<\/p>\n

\u201cUsing ribcage musculature was an evolutionary innovation fundamental to the conquest of the terrestrial realm by these earliest ancestors of modern reptiles and mammals.\u201d<\/p>\n

\u201cThis system likely also contributed to the explosive diversification of early amniotes, setting the stage for their dominance on land.\u201d<\/p>\n

\u201cIt was a game changer that allowed these animals to adopt a much more active lifestyle,\u201d Mooney added.<\/p>\n

Using synchrotron infrared spectroscopy, the researchers also detected remnants of original proteins preserved in the bone, cartilage, and skin.<\/p>\n

These organic molecules, never before seen in fossils from the Paleozoic era, are nearly 100 million years older than the previous oldest example, which was found in a dinosaur.<\/p>\n

\u201cThe protein remnant finding is exceptional,\u201d Mooney said.<\/p>\n

\u201cIt dramatically pushes our understanding of what is possible in terms of soft tissue preservation in the fossil record.\u201d<\/p>\n

The discovery is reported in a paper<\/a> in the journal Nature.<\/p>\n

_____<\/p>\n

R.R. Reisz et al. Mummified Early Permian reptile reveals ancient amniote breathing apparatus. Nature, published April 8, 2026; doi: 10.1038\/s41586-026-10307-y<\/p>\n","protected":false},"excerpt":{"rendered":"Paleontologists have examined 289-million-year-old specimens of the early reptile Captorhinus aguti that preserve a covering of three-dimensional skin,…\n","protected":false},"author":2,"featured_media":382392,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[146036,10740,182711,182712,95412,85,46,2819,9202,182713,5198,70783,182714,182715,182716,141,5095,1032],"class_list":{"0":"post-382391","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-amniota","9":"tag-breathing","10":"tag-captorhinus","11":"tag-captorhinus-aguti","12":"tag-cartilage","13":"tag-il","14":"tag-israel","15":"tag-north-america","16":"tag-oklahoma","17":"tag-permian","18":"tag-protein","19":"tag-reptile","20":"tag-ribcage","21":"tag-ribs","22":"tag-richards-spur","23":"tag-science","24":"tag-skin","25":"tag-united-states"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/382391","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/comments?post=382391"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/382391\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media\/382392"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media?parent=382391"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/categories?post=382391"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/tags?post=382391"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}