How did they live?
DR. T. V. PADMA
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Have you heard of the polar dinosaurs?
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How did the Southern Hemisphere's cold-blooded dinosaurs, sometimes called "polar dinosaurs" survive the harsh conditions? Palaeontologists have taken cross sections of dinosaur bones to get clues that help answer this question. Similar to tree rings, dinosaur bones also bear growth rings — by counting these rings, one can estimate the age of a deceased animal. Some polar dinosaur bones show rings that indicate that growth halted during some seasons — most likely in winter. So scientists think they might have hibernated to shelter from the cold. Then again, there are some dinosaurs that don't show halted growth. That must mean that they were active even in winter.
Warm or cold?
Palaeontologists proposed the theory that polar dinosaurs were, in fact, warm-blooded. Others put forward the idea of "gigantothermy" which says that large body sizes could have insulated dinosaurs from cold climates. This would imply that they would have to migrate seasonally to warmer climates, however, and other scientists have argued that this would have been impossible on the island habitats of Australia and New Zealand. The small size of many New Zealand and Victorian polar dinosaur fauna suggests that small dinosaurs must have had internal heat generating mechanism, even if it wasn't as efficient as the hot-blooded mechanism that birds and mammals have today. There is more support for this theory now.
How polar dinosaurs survived the harsh conditions, whether they survived the major extinction event that killed off most other dinosaur populations, and why they eventually died off, are still questions shrouded in mystery. May be you are interested enough in this topic to set these debates to rest some day?
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