The gorgonopsian, despite having four legs and a long tail, did not resemble a dog much, according to Angielczyk. Similar to reptiles, gorgonopsians lacked fur and visible ears. Although the creature shared some physical features with lizards, Angielczyk cautioned against labeling it a “lizard-dog,” explaining that gorgonopsians and lizards are part of separate evolutionary lineages – the former being nonmammalian therapsids in the lineage leading to mammals. While mammals and reptiles share a common ancestor from 320 million years ago, they have distinct lines of descent.
Gorgonopsians exhibit traits similar to their mammalian relatives, such as having teeth of various shapes and sizes that serve different functions in their feeding system. Unlike mammals, gorgonopsians continuously replaced their teeth, including their long canines, throughout their lives, a characteristic more akin to crocodiles. The oldest known gorgonopsian, discovered in Mallorca, Spain during expeditions in 2019 and 2021, sheds light on the evolutionary history of therapsids. This specimen is not only the oldest known gorgonopsian but also the oldest known therapsid to date.
The age of this specific gorgonopsian is significant, as it helps fill a gap in the fossil record of therapsids, clarifying their evolutionary timeline. Researchers had predicted the presence of therapsid fossils dating back 300 million years but had only found them from around 270 million years ago until now. The discovery of this specimen, which dates back at least to that period and possibly even earlier, aids in understanding the evolution of therapsids in the early Permian Period.
The search for early therapsids is crucial for tracing the ancestry of mammals, as the evolution of therapsids predates the mammalian line. This newfound gorgonopsian is a promising candidate for an early Permian therapsid, providing valuable insights into the early stages of therapsid evolution.
The researchers reported that previously, fossils of nopsid creatures were only found in dry, high-latitude regions in South Africa and Russia. Mallorca, during the Permian period, was located at the center of the supercontinent Pangea, which existed between 335 million and 200 million years ago. Positioned in the equatorial zone, what is now Mallorca would have undergone both very wet and extremely dry seasons.
Dr. Benson noted the curiosity surrounding the potential occurrence of significant events in mammal evolution in tropical regions, where fossils of these animals from the appropriate time period are lacking. The discovery of this fossil raises the intriguing possibility that crucial events in mammal evolution may have taken place in lower latitudes within environments that have not been extensively explored in the fossil record.
The identification of the oldest documented gorgonopsian in Mallorca suggests that there are likely more ancient therapsid fossils waiting to be unearthed in locations where paleontologists have not previously searched. As Dr. Angielczyk pointed out, there has been a longstanding belief that the significant temporal gap in the therapsid fossil record could be due to insufficient geographic exploration. The newfound presence of therapsid fossils in Mallorca supports the idea that researchers may need to broaden their search locations to uncover the earliest evidence of these ancient creatures.
Mindy Weisberger is a seasoned science writer and media producer whose work has been featured in prestigious publications such as Live Science, Scientific American, and How It Works magazine. For the latest CNN news updates and newsletters, users are encouraged to create an account on CNN.com.
