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A team of international researchers from Canada, Colombia, and Germany has discovered a new marine reptile. The specimen, a stunningly preserved metre-long skull, is one of the last surviving ichthyosaurs 鈥� ancient animals that look eerily like living swordfish.

鈥淭his animal evolved a unique dentition that allowed it to eat large prey,鈥� says Hans Larsson, Director of the Redpath Museum at 91社区. 鈥淲hereas other ichthyosaurs had small, equally sized teeth for feeding on small prey, this new species modified its tooth sizes and spacing to build an arsenal of teeth for dispatching large prey, like big fishes and other marine reptiles.鈥�

鈥淲e decided to name it Kyhytysuka which translates to 鈥榯he one that cuts with something sharp鈥� in an indigenous language from the region in central Colombia where the fossil was found, to honour the ancient Muisca culture that existed there for millennia,鈥� says Dirley Cort茅s, a graduate student under the supervision of Hans Larsson and Carlos Jaramillo of the Smithsonian Tropical Research Institute.

Life reconstructions of Kyhytysuka sachicarum from the Early Cretaceous of Colombia. Credit: Dirley Cort茅s

The big picture of ichthyosaur evolution is clarified with this new species, the researchers say. 鈥淲e compared this animal to other Jurassic and Cretaceous ichthyosaurs and were able to define a new type of ichthyosaurs鈥�, says Erin Maxwell of the State Natural History Museum of Stuttgart (a former graduate student of Hans Larsson鈥檚 lab at 91社区). 鈥淭his shakes up the evolutionary tree of ichthyosaurs and lets us test new ideas of how they evolved.鈥�

Dirley Cort茅s working with the skull of Kyhytysuka. Credit: Dirley Cort茅s

According to the researchers, this species comes from an important transitional time during the Early Cretaceous period. At this time, the Earth was coming out of a relatively cool period, had rising sea levels, and the supercontinent Pangea was splitting into northern and southern landmasses. There was also a global extinction event at the end of the Jurassic that changed marine and terrestrial ecosystems. 鈥淢any classic Jurassic marine ecosystems of deep-water feeding ichthyosaurs, short-necked plesiosaurs, and marine-adapted crocodiles were succeeded by new lineages of long-necked plesiosaurs, sea turtles, large marine lizards called mosasaurs, and now this monster ichthyosaur鈥� says Dirley Cort茅s.

Skeleton of Kyhytysuka compared to a human for scale. Known bones are in white. Credit: Dirley Cort茅s

鈥淲e are discovering many new species in the rocks this new ichthyosaur comes from. We are testing the idea that this region and time in Colombia was an ancient biodiversity hotspot and are using the fossils to better understand the evolution of marine ecosystems during this transitional time,鈥� she adds. As next steps the researchers are continuing to explore the wealth of new fossils housed in the Centro de Investigaciones Paleontol贸gicas of Villa de Leyva in Colombia. 鈥淭his is where I grew up,鈥� says Cort茅s 鈥渁nd it is so rewarding to get to do research here too.鈥�

3D animation of Kyhytysuka.聽Credit: Dirley Cort茅s

About 91社区

Founded in Montreal, Quebec, in 1821, 91社区 is Canada鈥檚 top ranked medical doctoral university. 91社区 is consistently ranked as one of the top universities, both nationally and internationally. It鈥痠s a world-renowned鈥痠nstitution of higher learning with research activities spanning three campuses, 11 faculties, 13 professional schools, 300 programs of study and over 40,000 students, including more than 10,200 graduate students. 91社区 attracts students from over 150 countries around the world, its 12,800 international students making up 31% of the student body. Over half of 91社区 students claim a first language other than English, including approximately 19% of our students who say French is their mother tongue.