Buzz
The incredible diversity of life on Earth today is awe-inspiring, and prehistoric creatures were no less extraordinary. Scientists have recently identified the owner of some remarkably unusual fossilized remains: a crocodile-sized, hammer-headed marine reptile with peg-shaped front teeth that thrived on a plant-based diet. The findings were detailed in a study published today in the journal Science Advances.
Discovered in Wushan, China, in 2014, the Middle Triassic species Atopodentatus unicus ("unique, strange-toothed") was initially thought to have a flamingo-like beak, possibly used for sifting worms and small invertebrates from the ocean floor. However, researchers noted that its delicate teeth were ill-suited for capturing prey. Instead, they suggested the teeth acted as a sieve to filter microorganisms or bottom-dwelling creatures like sea worms.
A year later, two additional Atopodentatus fossils were discovered in Beijing, offering better-preserved details of the creature’s jaws and snout. Despite the improved clarity, scientists remained puzzled by the anatomy. To better understand the structure, they turned to creative reconstruction methods, using craft materials to model the ancient reptile’s unique features.
Image Credit:(c) Olivier Rieppel, The Field Museum
“To understand how the jaw functioned and how this creature fed, we used children’s modeling clay, similar to Play-Doh, and reconstructed it with toothpicks to mimic the teeth,” explained Olivier Rieppel, co-author and curator of evolutionary biology at The Field Museum, in a press release. “By examining how the upper and lower jaws aligned, we were able to describe its feeding mechanism.”
Image credit: (c) Nick Fraser, National Museums Scotland
The team discovered that A. unicus had a hammer-shaped snout adorned with peg-like teeth at the front and needle-like teeth at the back, rather than a beak. This unique facial structure suggests that Atopodentatus likely fed by vacuuming up aquatic vegetation rather than foraging for worms.
Image credit: (c) Y. Chen, Institute of Vertebrate Paleontology and Paleoanthropology
“The creature employed its peg-shaped front teeth to scrape vegetation from underwater rocks, then opened its mouth to draw in the plant fragments,” Rieppel explained. “Its needle-like teeth acted as a filter, trapping the plants while allowing water to escape.”
Rieppel noted that many marine animals, such as baleen whales, utilize filter-feeding mechanisms, but Atopodentatus predates them by approximately eight million years.
The age of A. unicus is significant not only for understanding this species but also for insights into Earth’s history. The fossils, dating back around 242 million years, indicate that these creatures lived shortly after a major extinction event. “Studying animals from the Permian-Triassic period helps us understand how life responded to such catastrophic events,” Rieppel stated. “The presence of specialized species like Atopodentatus unicus suggests that life rebounded and diversified faster than earlier estimates indicated.”
