New research led by Mohamad Bazzi, along with Dr. Mike Newbrey and Tatianna Blake, has uncovered critical fossil evidence. This discovery upends what researchers thought was an earlier origin of megabody-sized lamniform sharks, a clade that includes modern great whites and mako sharks. Read all about their research and how these longtime apex predators came to dominate the world 15 million years earlier than we all believed. These scientists have conducted a detailed study of fossils from Australia’s Darwin Formation. Above, for example, their work has brought to light new knowledge in the evolutionary development of sharks and the environmental conditions that possibly contributed to their development.
A new study published in the journal Communications Biology uncovers a very cool finding. Our researchers discovered fossil vertebrae that are about 115 million years old! The specimen represents a new species of a 6-8 meter (19.5-26.3 ft) long body size among the fossil record. It happens to weigh more than 3 tons. This exciting new evidence pushes the date of appearance of large predators much further back. It implies that these invertebrates lived much longer ago than we thought.
The Research Team’s Findings
Bazzie and his team were primarily working with a dataset of vertebrae from ten species of living lamniform sharks. They compared this data, including with tracked known body lengths, to then accurately predict the size of the fossil specimens. Their work indicates that megabody sharks began their evolutionary odyssey long before the Late Cretaceous era. That conclusion contests earlier interpretations that had given sole credit to that time period, lasting from 100.5 to 66 million years ago, for their development.
Dr. Newbrey made sure to highlight the importance of their findings beyond just the implications for chatter marks. “As a field, we are curious about the environmental and ecological conditions needed to evolve mega-body size,” he stated. “Being able to estimate body size from isolated vertebral material will enable us to answer larger questions about shark evolution while considering the effects of climatic change.”
The fossil evidence raises some pretty fascinating questions about their ecology and how such sharks began to adapt to new environments. Dr. Newbrey postulated that the larger cardabiodontid species thrived during cooler conditions. He speculated that their large size may have enabled them to flourish in cooler temp waters. “We speculate that large body size may have enabled these particular sharks to survive in colder waters, thereby capitalizing on a vacant niche filled today by other large lamniform sharks,” he explained.
The Role of Student Researchers
The most important element of this research project is that students played an important role in faculty-led initiatives. 2020 alumna Tatianna Blake, one of the participating students from that study, spoke to the profound impact made on her own experience by mentorship from Dr. Newbrey. “The structure of my undergraduate program—which required students to engage in faculty-led research—was instrumental in exposing me to research in the first place,” she said. “The hands-on nature of the project itself provided the foundation I needed to appreciate and pursue research further.”
Though challenging, Blake’s path to a career in marine science was deeply influenced by her experience with this project. “Dr. Newbrey’s passion for ichthyology inspired me to explore fish research myself,” she noted, highlighting how working with actual fossil specimens ignited her interest in the field. “That experience sparked a deeper appreciation for research and its broader impact.”
Dr. Newbrey’s passion for cultivating diverse and inclusive experiences for students has introduced them to hands-on experience well before the professional world in the academic pipeline. “Students perform best academically, and later professionally, when they have opportunities to apply what they learn by doing,” he stated. He feels this method truly empowers students, deepening their understanding of how what they learn in the classroom gets applied out in the real world.
Implications for Future Research
The results from this study are destined to have a lasting impact on the direction of future research within the field of marine science. Paleobiologists are pushing the timeline of megabody-sized sharks occupying apex predator niches back considerably. This dramatic shift presents all kinds of tantalizing new questions regarding their evolutionary history and ecological drivers shaping different geological epochs.
Dr. Newbrey also added that continued exploration is key to understanding the evolution of sharks and their adaptations to different environments. “We strive to include our students in research opportunities early in their studies so they can realize the power and potential of how what they learn in the classroom contributes to science and education fields,” he remarked.
Tatianna Blake preparing for her next academic journey. She’s looking forward to acceptance into a doctoral program, equipped with incredible lessons learned from her hands-on research experience. She reflects on her journey, stating, “[T]hat opportunity alone had a lasting impact on my academic trajectory.”