![\"Life](\"https:\/\/cdn.sci.news\/images\/enlarge14\/image_15117e-Megacauda-sungei.jpg\")
<\/a><\/p>\nLife restoration of Megacauda sungei. Image credit: April I. Neander.<\/p>\n
Megacauda sungei belonged to the docodonts, an extinct group of early mammaliaforms (living mammals and their extinct relatives).<\/p>\n
At roughly 0.5 m (1.6 feet) long and one to two kilograms, about the size of a modern platypus, it is the largest Jurassic mammaliaform known. Most of its contemporaries weighed only a few grams.<\/p>\n
The species had a wide, flattened tail, short hindlegs with relatively long feet, and distinctive teeth capable of shearing action.<\/p>\n
It may have sheltered in burrows on land, and foraged in the water for fish, salamanders and invertebrates.<\/p>\n
\u201cIt is the earliest evidence of an aquatic lifestyle in mammals,\u201d noted University of Bonn paleontologist Dr. Thomas Martin.<\/p>\n
Megacauda sungei\u2019s remains also include exceptionally well-preserved pharynx and throat bones.<\/p>\n
They show a configuration like that of living therian mammals, the group that includes marsupials and placentals like us.<\/p>\n
\u201cMany species of animal do not have a soft palate and only have a simple hyoid bone apparatus without a swallowing mechanism,\u201d Dr. Martin said.<\/p>\n
\u201cCrocodiles, for instance, raise their head up and use jerky movements to make their unchewed prey slide down their throat. This is achieved with the aid of gravity.\u201d<\/p>\n
\u201cIn contrast, mammals, with their complex hyoid structure in the pharynx, are even able to swallow against gravity: as a result, we humans can drink upside down through a straw while breathing.\u201d<\/p>\n
\u201cThis ability is a key adaptation that allows mammals to feed on nutrient-rich milk and swallow it safely without it entering their nose.\u201d<\/p>\n
\u201cIt was this adaptation that made brain development, eventually leading to humans, possible.\u201d<\/p>\n
\u201cThe soft palate and the shaping of the oral cavity and pharynx are directly linked to the evolution of mammals.\u201d<\/p>\n
\u201cThis new development was already apparent in Megacauda sungei long before the emergence of modern mammals.\u201d<\/p>\n
The authors conclude that the anatomy for mammal-like swallowing, drinking and suckling was already present in the common ancestors of docodonts and mammals, long before modern mammals appeared.<\/p>\n
The discovery also adds to evidence that early mammal relatives were more varied than their small size suggests.<\/p>\n
\u201cIt expands the body size range of docodontans, and adds to a growing body of evidence that multiple docodontans exploited diverse niches with semiaquatic and other ecomorphotypes,\u201d the researchers said.<\/p>\n
\u201cDocodontans are an early example of replicated evolution of the semiaquatic and other ecomorphotypes in the Mesozoic ecosystem dominated by dinosaurs, long before the diversification of living mammals.\u201d<\/p>\n