Animals  
'Ball Mills' of the Dinos
by VK Joshi

Dinosaurs ruled our earth for 165 million years. In fact their rule ended only about 65 million years ago. Thereafter these giants vanished, became extinct. But then how do we know so much about them? The hard body parts of animals under favorable conditions get fossilized. Therefore today we get clues about the 'life style' of the dinos only through their fossil bones, eggs, coprolites (Fecal matter) and foot prints.

Conjectures have been made about their body functions from the giant bones. For example, Seismosaurus which is estimated to be over 30 meters and weighed over 120 tonnes and must have had a heart as powerful as water pump! To provide adequate oxygen to such a powerful heart, powerful lungs must have been inevitable. To keep his huge body fit and alive this giant consumed about two tonnes of food daily.

In India a young army Captain of the East India Company, William Sleeman was the first one to find a cache of large bones in 1828 in the Jabalpur Cantonment. Since then a number of discoveries have been made in the Narmada valley from Jabalpur in Madhya Pradesh to Kheda in Gujarat.

The structure of the fossil bones of dinosaurs has been subjected to intense studies under the microscope. The experts have been able to decipher the system of haversian canals in their bones which carried blood supply to each and every corner of the bone. We humans suffer a lot from bone related diseases like arthritis and often advised by the doctors to reduce weight. Imagine a dino, how much weight he had to carry on his pillar like bones! God only knows if he too suffered from bone related diseases!

Dinosaur eggs are a great fascination for the paleontologists. Their huge eggs had such structure that they were hard enough to escape the predators, yet soft enough for the baby dino to breakthrough on birth. Recently the paleontologists joined hands with engineers and doctors to use a mathematical technique called Finite Element Modeling to work out detailed structure of dinosaur eggs and also to find causes of occasional failures of eggs. Their work shows how the nature acts as an expert architect to produce perfect eggs.

Teeth and skull of dinosaurs give clues regarding their eating habits. With the help of teeth vegetarian and non-vegetarian dinosaurs are distinguished. It is interesting to know that the tooth of the first meat eating dinosaur from India, Massopondylus was found by one Rev. Stephen Hislop in 1861 near Nagpur. This dinosaur tooth more than six centimeters long points toward an animal with a skull more than two meters long. It must have been a veritable eating machine!

Smooth, hard polished stones often recovered along with the bones of plant eating dinosaurs are called by the palaeontologists as gastroliths or stomach stones. Some reptiles and birds also carry gastroliths. These gastroliths act as 'ball mills' inside the stomach of the organism and aid in grinding' the food. The gastroliths of the dinosaurs are comparatively large in size. Incidentally gastroliths are found near bones of plant eating dinosaurs with weak dental structure. Perhaps the ball mills were required by the dinosaurs to grind the extra hard vegetable matter!

What caused these powerful giants to become extinct is a debatable yet. May be the fossil dinosaurs of India hold the secret! Only time will tell.    

December 3, 2006

Images under license with Gettyimages.com and courtesy of GSI
Images shown (1) Gallimimus, running dinosaur; (2) Skeleton of the giant Kotasaurus Yamanpalliensis, Birla Science Centre, Hyderabad and (3) Giant eggs of a Theropod dinosaur, Dinosaur Fossils Park , Rahioli, Gujarat.

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