Euramerica of amphibian diversity and simultaneously the drier climate spurred the diversification of reptiles. Euramerica became a part of the major supercontinent Pangaea in the Permian. In the Jurassic, when Pangaea rifted into two continents, Gondwana and Laurasia, Euramerica was a part of Laurasia. In the Cretaceous, Laurasia split into the continents of North America and Eurasia. The Laurentian craton became a part of North America while Baltica became a part of Eurasia, and Avalonia was split between the two. Euramerica Euramerica (also known as Laurussia – not to be confused with Laurasia, – the Old Red Continent or the Old
Unenlagiinae Unenlagiinae Unenlagiinae is a subfamily of dromaeosaurid theropods. Unenlagiines are known from South America and Antarctica. Most unenlagiines have been discovered in Argentina. The largest was "Austroraptor", which measured up to 5–6 m (16.4–19.7 ft) in length, making it also one of the largest dromaeosaurids. The subfamily is distinguished from other dromaeosaurids by a tail stiffened by lengthy chevrons and superior processes, sharp articulate claws, and a posteriorly oriented pubis. Their distinct anatomy from Laurasian dromaeosaurids was likely a consequence of the breakup of Pangaea into Gondwana and Laurasia, where the geological isolation of unenlagiines from their relatives resulted in