Graphic showing functional optimality drives repeated evolution of extreme saber tooth forms (Credit: Tahlia Pollock)NewsletterSign up for our email newsletter for the latest science newsThe curved teeth of the saber-tooth tiger represents an evolutionary paradox. Gaining its trademark curved fangs made it functionally optimal for piercing the flesh of its prey. But that level of evolutionary specialization may have also contributed to the big cat's demise about 10,000 years ago, according to a new study published in Current Biology. Our study helps us better understand how extreme adaptations evolve not just in saber-toothed predators but across nature, Tahlia Pollock, a Bristol University researcher and author of the paper, said in a press release.Learning How Teeth Shape Affect Hunting AbilityTo reach that conclusion, a team of researchers first used computer simulations on 235 teeth representing 95 different meat-eating mammals including 25 from various saber-toothed ones. Then they 3-D printed 14 stainless steel teeth covering the range of shapes, and measured the amount of force each model tooth needed to puncture gelatin. The team analyzed a wide variety of teeth shapes and sizes. They were especially interested in the balance between curved versus straight and slender versus thick. "There is a trade-off between the aspects of shape that improve food fracture and those that increase tooth strength, according to the paper.Not surprisingly, the classic saber-toothed tiger Smilodon fatalis as well as its lesser well-known cousin, the false saber-toothed Barbourofelis fricki scored the highest marks for predators with curved teeth. Thylacosmilus atrox and Hoplophoneus primaevus both extinct big cats with shorter, thicker, and straighter teeth also performed well, according to the study.Seeking Evolutionary Advantages The common opossum and giant pandas teeth were among the poorest performers, requiring the most pressure to pierce the gelatin. Thats not surprising, since neither animal is known for its hunting skills.The tests help explain evolution among saber-toothed predators. There are at least five different examples of such teeth at different points in time. Those teeths ability to puncture yet not break definitely provided an advantage.The Peril of Over-SpecializationBut they could have also led to those animals demise. While that degree of specialization may have helped the big cats successfully hunt smaller mammals, it may have been a disadvantage as the climate changed. For instance, S. fatalis went extinct about 10,000 years ago, when the Ice Age glaciers began melting, which changed wildlife habitat.By combining biomechanics and evolutionary theory, we can uncover how natural selection shapes animals to perform specific tasks, said Pollock in the release. The study also suggests that saber-toothed animals fall on a spectrum of teeth shape and size. The conventional wisdom had divided the creatures into two categories based on tooth shape: dirk-toothed and scimitar-toothed. This study suggests that animals developed different hunting strategies over time.The team next intends to widen their analysis to include all tooth types, with the goal of better understanding biomechanical trade-offs between different shapes and sizes.The findings not only deepen our understanding of saber-toothed predators but also have broader implications for evolutionary biology and biomechanics, Professor Alistair Evans, a Monash University researcher and author of the paper said in a press release. Insights from this research could even help inform bioinspired designs in engineering.Article SourcesOur writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:Before joining Discover Magazine, Paul Smaglik spent over 20 years as a science journalist, specializing in U.S. life science policy and global scientific career issues. He began his career in newspapers, but switched to scientific magazines. His work has appeared in publications including Science News, Science, Nature, and Scientific American.