This tiny jurassic predator helped pave the way for the human brain
A 165-million-year-old fossil has revealed an extraordinary Jurassic predator that may help explain how mammals developed one of their most important evolutionary advantages. Although only 20 inches long, Megacauda sungei was a heavyweight among early mammal relatives, swimming through ancient waterways and hunting prey with specialized teeth. Its advanced swallowing anatomy reveals an early step toward the ability…
Key points
- A 165-million-year-old furry predator called Megacauda sungei had a soft palate that let mammals swallow and breathe at the same time.
- The fossil, found in Inner Mongolia, is the largest known Jurassic mammaliaform at about half a meter long.
- Researchers say this adaptation made nursing and later brain development, including humans, possible.
Scientists have described a new species of ancient mammal relative that lived about 165 million years ago and already possessed a key anatomical feature linked to the evolution of mammals. The animal, named Megacauda sungei, measured roughly half a meter (20 inches) from nose to tail and hunted in water, using teeth with backward-curving cusps to grip slippery prey.
The fossil was discovered in Xiayingzi, Inner Mongolia, and studied by researchers in Shenyang, Chicago and Bonn. Their findings were published in the journal Nature.
A sophisticated swallowing mechanism
The team found evidence of a soft palate separating the mouth from the pharynx, the passage connecting the mouth to the throat. This allowed the animal to swallow while still breathing, an ability important for mammals that nurse their young.
Many animals lack a soft palate and rely on simpler hyoid bones in the throat. Crocodiles, for example, lift their heads and jerk to move unchewed food down, which Prof. Dr. Thomas Martin of the University of Bonn says is achieved with the aid of gravity. Mammals have a more elaborate hyoid structure, letting humans drink through a straw while upside down and still breathe.
It was this adaptation that made brain development, eventually leading to humans, possible.
— Prof. Dr. Thomas Martin
An aquatic hunter among dinosaurs
With short fur and a broad, flattened tail, Megacauda sungei resembled a modern otter, beaver or platypus. Computed tomography scans were used to build three-dimensional reconstructions suggesting it paddled with its front legs and moved its tail in an undulating motion, with its hind legs likely helping it change direction.
The fossil was part of a collection at the Paleontological Museum of Liaoning in Shenyang. Chang-Fu Zhou of Shandong University, Zhe-Xi Luo of the University of Chicago and Thomas Martin of the University of Bonn examined it together and named the species after Prof. Sun Ge, the museum's Honorary Director.
