Tag

Lystrosaurus

All articles tagged with #lystrosaurus

science1 month ago•43 min saved

Oldest Mammal-Ancestor Egg Fossil Confirms Egg-Laying

A fossil egg containing a Lystrosaurus embryo dating to about 250 million years ago provides the first direct evidence that mammal ancestors laid eggs. Synchrotron CT imaging at ESRF revealed the embryo was pre-hatching and the lower jaw had not fused, suggesting the hatchling was precocial. The egg was likely soft-shelled and relatively large for its owner, enabling survival in the post-extinction climate and helping Lystrosaurus dominate early ecosystems after the End-Permian mass extinction.

via Good News Network|

#eggs #fossil #lystrosaurus

biology1 month ago•17 min saved

Giant eggs helped early mammal ancestors weather the Great Dying

New ESRF X-ray CT analysis of a Lystrosaurus egg and embryo shows these proto-mammals laid large, soft-shelled eggs; the precocial hatchlings could feed themselves and reproduce, and the eggs’ low surface-area-to-volume ratio would resist desiccation, helping Lystrosaurus surge after the mass extinction and dominate post-extinction ecosystems.

via Gizmodo|

#biology #eggs #lystrosaurus

science1 month ago•174 min saved

Ancient mammal kin laid eggs, fossil rewrites mammal origins

A 250-million-year-old Lystrosaurus embryo fossil provides the first direct evidence that mammal ancestors laid eggs. High‑resolution imaging shows the embryo’s jaws were not fully fused, indicating an egg inside the egg with a soft leathery shell, suggesting water‑conserving eggs helped this dry‑habitat survivor endure the Great Dying. The discovery offers clues about the evolution of lactation and live birth, and implies that hatchlings were relatively mature at hatching, aiding early mammal lineages before milk secretion became widespread.

via CNN|

#eggs #evolution #lystrosaurus

science1 month ago•8 min saved

250-million-year fossil confirms mammal ancestors laid eggs

Using synchrotron X-ray CT, scientists examined a 250-million-year-old Lystrosaurus egg containing a curled embryo, providing the first direct evidence that mammal ancestors laid eggs, with large, yolk-rich soft shells and precocial hatchlings that helped survival after the End-Permian extinction.

via ScienceDaily|

#eggs #fossil #lystrosaurus

science1 month ago•4 min saved

Ancient egg fossil rewrites the story of mammal origins

A fossil from Oviston, South Africa, shows the therapsid Lystrosaurus laid eggs about 252–250 million years ago. X-ray analysis revealed an in-egg embryonic beak not yet fused, indicating hatchlings that could break out of a leathery shell, a trait shared with turtles and birds and providing the first strong evidence that mammal ancestors laid eggs. This egg-based reproduction may have helped these creatures survive the Great Dying and reshapes our understanding of mammalian origins, alongside today’s egg-laying mammals like the platypus and echidna.

via New York Post|

#eggs #lystrosaurus #mammals

science1 month ago•12 min saved

Oldest fossil egg confirms mammal ancestors laid eggs about 250 million years ago

Researchers analyzed a 252–250 million-year-old Lystrosaurus fossil egg found in South Africa and, using synchrotron imaging at the ESRF, revealed a curled embryo whose jaw bones suggest it was still in an egg. This proves therapsids (the precursor to mammals) laid eggs (oviparous) rather than giving live birth, offering clues about embryo development, egg size, and survival strategies after the Great Dying. The large, leathery eggs likely reduced desiccation and supported precocial hatchlings, informing our understanding of early mammalian reproduction and the evolution of lactation.

via The Conversation|

#eggs #evolution #lystrosaurus

science1 month ago•6 min saved

Ancient mammal ancestors laid eggs, fossil reveals

A 250-million-year-old Lystrosaurus fossil preserves a soft-shelled egg and a tiny embryo, providing the first direct evidence that mammal ancestors laid eggs; synchrotron X-ray imaging revealed an unfused jaw and an embryo that likely died inside the egg, suggesting large yolk-rich eggs and precocial hatchlings aided survival after the End-Permian extinction and reshaped ideas about mammalian origins.

via Indian Defence Review|

#egg-laying #end-permian-extinction #lystrosaurus