A new study led by researchers at The University of Texas at Austin has identified a new species of ancient crocodile ancestor, shedding light on the evolutionary history of these creatures. The research, published in The Anatomical Record, focuses on a well-preserved aetosaur specimen named Garzapelta muelleri.
William Reyes, a doctoral student at the UT Jackson School of Geosciences and the lead researcher, highlighted the significance of the find, stating, "We have elements from the back of the neck and shoulder region all the way to the tip of the tail." Reyes also noted the challenges posed by convergent evolution in understanding the placement of Garzapelta within the larger aetosaur family tree.
The newly identified species, Garzapelta muelleri, lived approximately 215 million years ago and boasted a heavily armored body similar to modern American crocodiles but with distinctive features. The bony plates, known as osteoderms, that covered Garzapelta's body were intricately arranged, forming a protective shield. Additionally, the creature's sides were adorned with curved spikes for added defense against predators.
Reyes emphasized the uniqueness of Garzapelta's armor, stating, "An array of unique features on Garzapelta’s plates clearly marked it as a new species." He also highlighted the challenges posed by convergent evolution, noting the complexities it introduces to phylogenetic analyses.
The study not only contributes to our understanding of aetosaurs but also underscores the importance of university and museum collections in advancing paleontological research. Bill Parker, an aetosaur expert, emphasized the critical role of such collections in enabling studies like this.
Reyes is continuing his research by exploring how factors such as age and sex may have influenced the appearance of aetosaur armor. By studying fossils from the Jackson School's collection, Reyes aims to further unravel the mysteries surrounding these ancient crocodile relatives.
The research, funded by the National Science Foundation and the Jackson School, was a collaborative effort involving Jeffrey Martz from the University of Houston-Downtown and Bryan Small from the Museum of Texas Tech University.