Megacauda Fossil Pushes Mammal-Like Throat Evolution Back 165 Million Years
Updated
Updated · Sci.News · Oct 8
Megacauda Fossil Pushes Mammal-Like Throat Evolution Back 165 Million Years
3 articles · Updated · Sci.News · Oct 8
Summary
Exceptionally preserved throat bones in Megacauda sungei show a therian-like pharynx, indicating mammal-style swallowing, drinking and suckling had evolved 165 million years ago.
The otter-size, semiaquatic mammaliaform from Inner Mongolia also appears to be the earliest known aquatic mammal relative, with a flattened tail, short hindlegs and long feet suited for swimming.
At 0.5 meters long and 1-2 kilograms, Megacauda was the largest known Jurassic mammaliaform; most contemporaries weighed only a few grams.
The Nature study suggests the anatomy behind safe milk feeding and more complex mammalian development arose in ancestors of docodonts and mammals well before modern mammals appeared.
The find adds to evidence that early mammal relatives were ecologically diverse, with docodonts already occupying semiaquatic niches in dinosaur-dominated Mesozoic ecosystems.
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?