China Fossil Reveals 163-Million-Year-Old Semiaquatic Mammaliaform Megacauda sungei
Updated
Updated · ABC News · Oct 7
China Fossil Reveals 163-Million-Year-Old Semiaquatic Mammaliaform Megacauda sungei
3 articles · Updated · ABC News · Oct 7
Summary
Megacauda sungei, found in Inner Mongolia and dated to 168-163 million years ago, is now the oldest-known semiaquatic mammaliaform and an early mammal relative with platypus-like traits.
The 1-2 kilogram animal had webbed feet, a flattened otter-like tail and dense fur for swimming, but also strong canine and slicing teeth that suggest it hunted fish and salamanders.
Nature placed Megacauda on the extinct Docodonta branch, and researchers said the unusually complete fossil shows semiaquatic adaptation emerged early in mammal evolution.
The find pushes the record beyond Castorocauda, which lived 164-159 million years ago in the same region, and far predates the earliest known semiaquatic true mammal from about 120 million years ago.
Did a chihuahua-sized Jurassic swimmer just rewrite the evolutionary timeline of how modern mammals learned to nurse their young?
If this 165-million-year-old creature possessed a modern mammalian throat, did egg-laying mammals like the platypus actually lose their ancestral suckling abilities?
Could the salamander bones found with this ancient predator prove that complex swallowing evolved millions of years earlier than previously believed?