Research: Ancestors of mammals laid eggs (PHOTOS)

(SeaPRwire) –   The analysis of a Lystrosaurus baby fossil has resolved a long-standing scientific question

A 250-million-year-old fossil, recently examined, provides evidence that early mammalian ancestors laid eggs, as detailed in a paper released Thursday in the journal PLOS One.

Although modern egg-laying mammals like the platypus and echidnas still exist, researchers have searched for decades to confirm this trait in more ancient forebears.

South African Professor Jennifer Botha, a lead scientist on the project, explained that the fossil was found in 2008 but required sophisticated, non-invasive scanning techniques to be properly studied years later.

“It became clear that it was a perfectly curled-up Lystrosaurus hatchling. I suspected even then that it had died within the egg, but at the time, we simply didn’t have the technology to confirm it,” she stated in a comment reported by phys.org.

Employing advanced synchrotron X-ray CT scanning—a technique that uses a particle accelerator to generate highly detailed, non-destructive 3D images—allowed for an in-depth examination of the fragile specimen.

Lystrosaurus was a plant-eating precursor to mammals that not only survived but flourished in the chaotic era after the End-Permian Mass Extinction roughly 252 million years ago. This event is thought to have eradicated up to 96% of marine life and 70% of terrestrial vertebrates. The disaster is hypothesized to stem from enormous volcanic activity and subsequent coal combustion, triggering swift global warming and creating a planet of intense heat and environmental upheaval.

According to the study, Lystrosaurus probably produced soft, leathery eggs. Such pliable eggs fossilize far less often than hard-shelled ones, accounting for the scarcity of such finds.

Based on the hatchling’s stage of growth and characteristics, Lystrosaurus likely did not lactate but instead deposited sizable eggs, which better resist desiccation in hot, dry conditions, as noted by Botha’s institution, Witwatersrand University.

Its offspring probably emerged from the egg already well-developed, prepared to forage independently and survive in the harsh environment left by history’s most severe extinction.