# Jurassic Predator Megacauda Reveals Early Mammalian Throat Evolution A 165-million-year-old fossil shows complex swallowing mechanics existed long before modern mammals. - **Source:** [Earth.com](https://www.earth.com) - **Published:** 2026-11-08 - **Topic:** [science](https://brifing.si/c/science) - **Original article:** - **On Brifing:** https://brifing.si/s/9ee6e962-417a-4c2c-b534-77ddd5a5e7db ## Ancient Swimming Predator Found Researchers discovered Megacauda sungei, a Jurassic-era mammal relative, in Inner Mongolia. Dating back 163 to 168 million years, this creature weighed between 2.2 and 4.4 pounds. It stands as the largest known mammal relative from that period, significantly outweighing other docodonts found in the same geological rock formations. ## Unique Dental and Physical Traits The predator possessed distinct three-rooted fangs, a feature unseen in other known mammals. Its cheek teeth featured blade-like points for slicing, similar to modern seals. With a wide, flattened tail and specialized hind feet, the animal was physically adapted for a semi-aquatic lifestyle, hunting fish and salamanders in water. ## Advanced Throat Anatomy Discovered CT scans revealed a bony hook at the skull base, mirroring structures used by modern mammals for nursing and swallowing. This indicates that the complex muscular system required for drinking and sealing the nasal passage during swallowing evolved much earlier than previously thought, appearing in this extinct docodont lineage. ## Evolutionary Significance of Docodonts Docodonts were a diverse group of extinct animals related to true mammals that thrived across northern continents for 100 million years. Megacauda represents the earliest known instance of a mammal relative adopting a semi-aquatic lifestyle. This discovery highlights the remarkable ecological diversity these creatures achieved during the middle Jurassic period. ## Reconstructing Ancient Soft Tissue Since muscles do not fossilize, researchers reconstructed the animal's throat mechanics by comparing bone attachment points to living species like the opossum. The presence of saddle-shaped bones and specific grooves suggests that swallowing, drinking, and nursing equipment likely evolved as a complete functional set rather than in gradual, isolated stages. ## Comparison to Modern Swimmers While Megacauda shared traits with platypuses and otters, it was likely a less efficient swimmer. Its tail muscles did not extend as far down the tail as those of modern aquatic mammals, providing less propulsion. It likely balanced its time between hunting in water and sheltering in land-based burrows. ## Scientific Collaboration and Methodology The study involved researchers from Shenyang Normal University, Shandong University of Science and Technology, the University of Chicago, and the University of Bonn. Led by Thomas Martin, Zhe-Xi Luo, and Chang-Fu Zhou, the team analyzed a single skeleton currently housed at the Paleontological Museum of Liaoning to reach their conclusions. ## Limitations of Current Findings All conclusions are based on a single fossil specimen. While the throat anatomy suggests the capacity for nursing, this cannot be definitively proven from bone structure alone. Future research requires additional, well-preserved docodont fossils to confirm how these early creatures interacted with their young and maintained their complex feeding habits. ## Sources covering this story - https://www.earth.com/animals/scientists-discovered-a-tiny-furry-predator-from-165-million-years-ago-that-hunted-slippery-prey-in-the-water/ — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._