Theory on why dinosaurs developed long necks

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Sauropods of Gondwana

Scientists have come to a neat theory as to why some of the best-known dinosaurs evolved into having such enormously long necks. And when you think about it, it makes sense. Over millions of years they developed long necks to feed from the leaves of a tree which had survived a massive version of global warming due to volcanoes belching carbon dioxide into the atmosphere. This massive climate change decreased the diversity of plants. Some survived and these were a group of tall conifer trees with tiny leaves. The only animals able to feed on the leaves were those with long necks and so the theory that the fittest survive clicked into action and the longnecked sauropods came into being.

Sauropods of Gondwana

Sauropods of Gondwana. Photos: Sauropods – Amazon. Gondwana map – Griem (2007).

This was the Toarcian era. Scientists dug up a fossil in Patagonia and believe that they’ve solved the mystery of the long-next dinosaurs. In addition to sauropods the long-neck dinosaurs include the famous brontosaurus and the diplodocus. The brontosaurus is the dinosaur we frequently see in illustrations from that era about 180 million years ago.

They believe that this aspect of evolution occurred in southern-Gondwana. This is an ancient supercontinent which eventually broke up to form Africa, South America, Antarctica, Australia and the Indian subcontinent and the Arabian Peninsula.

The theory is perhaps unique in that it describes how ancient plant life dictated the evolution of ancient animals. And of course the plant life was dictated to by climate change at that time. This is perhaps pertinent to today’s climate change crisis. Perhaps we will be able to predict some similar changes in today’s world!

The sauropods weighed up to 50 tons and became a dominant animal species for 100 million years. All sauropods had the same anatomy: a very long neck leading to a large gut and the whole construction supported by massive legs. Their skulls were deep and robust. They had broad teeth and strong jaws, necessary tools to strip the leaves and grind them down for digestion. Their necks had evolved to an optimal browsing height.

It’s an anatomy which is suited to eating leaves high up in trees, much like the anatomy of today’s giraffes. Perhaps the scientist got their idea from the giraffes because there is a great similarity anatomically speaking.

To sum up, in scientific terms, the authors of the study published in the Proceedings of the Royal Society B state that: “..the dominant trees likely acted as a strong selective regime favouring the survival and success of eusauropods”.