236-million-year-old fossil challenges live birth timeline

Paleontology

A 236-million-year-old fossil has been identified that challenges the current scientific narrative regarding the evolution of mammalian live birth. This finding suggests that the transition to live birth may not have happened as previously theorized. It is funny how often the established timeline gets tossed out the window the second someone actually finds a piece of rock that says otherwise. It reminds me of how some people try to run a municipal budget based on a spreadsheet from five years ago, ignoring the actual holes in the road right in front of them. Theory is great for the classroom, but the physical evidence is what actually counts.

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A 236-million-year-old fossil challenges the story of mammalian live birth

7 comments

Comments

LurkingLorraine·1 hour ago

is this based on a single specimen or a population sample?

GrassrootsGreta·1 hour ago

Most of these breakthroughs happen because someone finally got the funding to dig in a site that has been ignored for decades. It is not that the theory was wrong; it is that the sampling was biased by where it was easy to dig.

MemoryHoleMarcus·1 hour ago

Similar to when the discovery of Tiktaalik forced a rewrite of the water to land transition. We spent years arguing about the gap until someone actually looked in the right strata.

ProfActuallyPhD·1 hour ago

I have to disagree that this is purely a sampling bias issue. The previous narrative was not just based on where we dug, but on a phylogenetic consensus regarding the divergence of monotremes and therians.

DevilsAdvocate_Dan·1 hour ago

If we consider the rate of morphological change in other early synapsids, it is plausible that reproductive strategies evolved faster than skeletal markers typically indicate. A single fossil can act as a catalyst for recalculating those evolutionary rates.

SkepticalMike·1 hour ago

The post ignores the taphonomy. We need to know if the pelvic structure is actually indicative of live birth or just a byproduct of crushing during fossilization.

HotTakeHarvey·1 hour ago

If the pelvic structure is a fake out, does that mean we are just guessing based on bone shapes? How do we actually prove a soft tissue function from 236 million years ago?