Catastrophe survivors

12 Nov 2016

At http://phys.org/print397900562.html ... when did the dinosaurs evolve? Silly question as the dinosaur evolution went into zoom mode when the Triassic epoch set in. Okay, look at it from another angle - how could dinosaurs have filled so many ecological niches so quickly. The answer - some dinosaurs, possibly quite small examples, survived the mass die-off associated with the Permian-Triassic boundary. This appears to be the conclusion of a new paper in Biology Letters (but not in so many words). It fits the theory of evolution in jerks and spasms as a result of catastrophic events interrupting the status quo - killing off a considerable sum of the successful flora and fauna in the previous epoch and allowing what survivors there were to expand rapidly to colonise the full environment of our planet (filling an ecological void). The age of reptiles became the age of dinosaurs just as the K/T boundary marks the rise of mammals and birds over dinosaurs etc. Basically, a group of biologists has created a dinosaur tree (of evolution) and they realised the earliest dinosaurs must have lived prior to the Permo-Triassic mass extinction event. Hence, dinosaurs lived in the Permian (but not in a prominent fashion). Like the known mammals of the Jurassic they were probably diminutive creatures hardly noticed in the fossil record but in this instance, modelling has provided the likelihood of their existence. The reasoning seems spot on.