{"id":383048,"date":"2026-04-16T20:40:15","date_gmt":"2026-04-16T20:40:15","guid":{"rendered":"https:\/\/www.newsbeep.com\/nz\/383048\/"},"modified":"2026-04-16T20:40:15","modified_gmt":"2026-04-16T20:40:15","slug":"the-cockroach-of-dinosaurs-likely-survived-extinction-because-of-its-big-wet-eggs","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/nz\/383048\/","title":{"rendered":"The Cockroach of Dinosaurs Likely Survived Extinction Because of Its Big Wet Eggs"},"content":{"rendered":"

Fantastic numbers of leathery, beaked Lystrosaurus\u2014a distant ancestor to today\u2019s mammals, often<\/a> the size of a small dog\u2014roamed the sulfurous wastelands of Pangea<\/a> after the Permian\u2013Triassic extinction event<\/a> over 251 million years ago. While many of its predators were busy suffocating to death under the endless volcanic<\/a> soot and sweltering temperatures that led to this era\u2019s \u201cGreat Dying,\u201d the little plant-eating Lystrosaurus is believed to have burrowed<\/a> and hibernated<\/a> its way to safety.<\/p>\n

Now, Paleontologists understand one more quirk of the many far-flung species that once made up the genus Lystrosaurus: These proto-mammals laid eggs\u2014and the sheer size of those eggs were likely critical to their survival.<\/p>\n

Lystrosaurus reproduced via eggs so large compared to its own body weight, in fact, that researchers now believe that baby Lystrosaurus were born ready to roll\u2014advanced enough in their development to evade predators, feed themselves, and even make more little Lystrosaurus. Their larger eggs would have also enjoyed another major advantage during this overheated post-apocalypse: a low \u201csurface area to volume ratio\u201d that would have made them less prone to fatal drying out, or \u201cdesiccation,\u201d according to a new study<\/a> of the first confirmed egg containing an embryo of a Lystrosaurus.<\/p>\n

\u201cThis fossil was discovered during a field excursion I led in 2008,\u201d paleontologist Jennifer Botha, a professor at University of the Witwatersrand in South Africa and a coauthor on the new study, said in a statement<\/a>. \u201cI suspected even then that it had died within the egg, but at the time, we simply didn\u2019t have the technology to confirm it.\u201d<\/p>\n

Ghost in the shell <\/p>\n

At the field site, Botha was convinced that her team had uncovered a \u201cperfectly curled-up Lystrosaurus hatchling,\u201d but it would take new and more sophisticated X-ray scanning<\/a>\u2014via a beam intensified within a particle accelerator known as a synchrotron<\/a>\u2014to get a clearer picture of this fossil. Specifically, it would take well over a decade, and a massive construction project at the European Synchrotron Radiation Facility (ESFR), for such a device to come online. In 2022, ESFR\u2019s BM18<\/a> beamline synchrotron X-ray CT imager, became operational.<\/p>\n

That\u2019s where Botha\u2019s coauthor, Vincent Fernandez, a permanent beamline scientist at the ESFR in Grenoble, France, came in. Fernandez put the fossil under both X-ray micro-computed tomography (CT) and the new BM18<\/a> beamline imager. The high-energy X-ray\u2019s employed by the BM18 gave the team a resolution<\/a> inside the fossil down to just under 18 micrometers.<\/p>\n

\u201cIt was essential that we scanned the fossil just right to capture the level of detail needed to resolve such tiny, delicate bones,\u201d Fernandez said in a statement.<\/p>\n

\"3dAbove, a 3D reconstruction of the fossilized Lystrosaurus embryo skeleton, scanned via a high-energy BM18 beamline X-ray method at ESRF in France. Credit: Professor Julien Benoit <\/p>\n

The scans illuminated a hidden detail in the Lystrosaurus hatchling\u2019s skeletal structure that confirmed it was much more likely that the specimen had been fossilized as an embryo rather than a newborn.<\/p>\n

\u201cWhen I saw the incomplete mandibular symphysis, I was genuinely excited,\u201d paleontologist and coauthor Julien Benoit said in a statement. \u201cThe mandible, the lower jaw, is made up of two halves that must fuse before the animal can feed. The fact that this fusion had not yet occurred shows that the individual would have been incapable of feeding itself.\u201d<\/p>\n

The hatchling, in other words, had not yet hatched.<\/p>\n

\"EuropeanAbove, an aerial view of ESRF\u2019s particle accelerator. \u00a9 2017, Etienne Baudon, via Flickr, Public Domain 1.0 Soft-shell, alternative architecture <\/p>\n

The three researchers hypothesize that Lystrosaurus young likely hatched from \u201csoft and leathery\u201d eggs, which would resolve the perplexing issue of why no prior eggs have ever been discovered for these creatures anywhere in the extant fossil record.<\/p>\n

Dinosaur eggs, which typically have much harder shells, will readily calcify into fossils\u2014as wet mineral deposits essentially weatherize them, literally setting the eggs in stone. Lystrosaurus\u2019 soft-shelled and more mammalian eggs, on the other hand, would more than likely decay anonymously into dust.<\/p>\n

\"LystrosaurusAbove, an artistic reconstruction of the Lystrosaurus embryo as it may have once appeared in its partially preserved shell. Credit: Professor Julien Benoit and Sophie Vrard <\/p>\n

\u201cUnderstanding reproduction in mammal ancestors has been a long-lasting enigma,\u201d Fernandez said, \u201cand this fossil provides a key piece to this puzzle.\u201d<\/p>\n

According to the ESRF\u2019s official statement, the team\u2019s discovery is not only \u201cthe first direct evidence of egg-laying in mammal ancestors\u201d but also \u201ca powerful explanation for how Lystrosaurus came to dominate post-extinction ecosystems.\u201d<\/p>\n

Despite their cozy reputation, as sedentary, leaf-chewing burrowers\u2014happy to ride out a torturous<\/a>, roughly two-million-year-long extinction event\u2014Lystrosaurus survived by growing up fast.<\/p>\n","protected":false},"excerpt":{"rendered":"Fantastic numbers of leathery, beaked Lystrosaurus\u2014a distant ancestor to today\u2019s mammals, often the size of a small dog\u2014roamed…\n","protected":false},"author":2,"featured_media":383049,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[6580,30716,128562,111,139,69,6581,147],"class_list":{"0":"post-383048","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-dinosaurs","9":"tag-mammals","10":"tag-mass-extinction","11":"tag-new-zealand","12":"tag-newzealand","13":"tag-nz","14":"tag-paleontology","15":"tag-science"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/383048","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=383048"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/383048\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/383049"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=383048"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=383048"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=383048"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}