Crocodile evolution rebooted by Ice Age glaciations
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Researchers discover impacts of Ice Age sea level changes in the genomes of Caribbean and Pacific crocodiles in Panama
Published: 16Feb2021
Image by José Avila-Cervantes.
Crocodiles are resilient animals from a lineage that has survived for over 200 million years. Skilled swimmers, crocodiles can travel long distances and live in freshwater or marine environments. But they can’t roam far on land. American crocodiles (
Crocodylus acutus) are found in the Caribbean and Pacific coasts of the Neotropics but they arrived in the Pacific before Panama existed, according to researchers from McGill University.
Over 3 million years ago, the formation of the Isthmus of Panama altered global ocean circulation, connecting North and South America and establishing the Caribbean Sea. This resulted in widespread mixing of species on the continent and separation in the seas. On land, mammals from North America such as ma
Discovery of new praying mantis species from the time of the dinosaurs
A McGill-led research team has identified a new species of praying mantis thanks to imprints of its fossilized wings. It lived in Labrador, in the Canadian Subarctic around 100 million years ago, during the time of the dinosaurs, in the Late Cretaceous period. The researchers believe that the fossils of the new genus and species
, Labradormantis guilbaulti, helps to establish evolutionary relationships between previously known species and advances the scientific understanding of the evolution of the most ‘primitive’ modern praying mantises. The unusual find, described in a recently published study in
Rainfall patterns remained largely unaffected despite dramatic climate changes
It’s known that the primary cause of the mass extinction of dinosaurs, about 66 million years ago, was a meteorite impact. But the exact mechanisms that linked the meteorite impact to mass extinction remain unclear, though climactic changes are thought to have played a part.
To understand how the mass extinction and associated climate changes affected specific ecosystems, a team of McGill scientists has analyzed the microscopic remains of plants from this period, found in the sediment of rivers in southern Saskatchewan. In a recent article in Palaeogeography, Palaeoclimatology, Palaeoecologythey show that in this area, local plant communities and ecosystems experienced a long-term shift towards fewer aquatic plants and an increase in terrestrial plants, including trees such as birches and elms. They researchers speculate that this increase was due to the extinction of large plant-eating dinosaurs. The