Titans in the Palm of Your Hand

Revelations about the largest of dinosaurs from the smallest of fossils

by Dave Board

Nature proved her sense of irony when she revealed the cranial anatomy of the largest of all known dinosaurs-the Titanosaurs-in the minute and fragile bones of their embryos. Instead of finding adult bones, researchers recently uncovered the unique shape of Titanosaur skulls inside six fossilized eggs from Patagonia.

The eggs were found in the Auca Mahuevo ("many eggs") fossil beds. Inside the eggs, tiny bones from long-extinct dinosaur fetuses awaited discovery and dissection.

Dinosaur egg shell covers the ground at the fossil site, first located in 1997. Dr. Luis Chiappe of the Los Angeles County Natural History Museum says the region was once an enormous nesting ground for the long-necked dinosaurs.

"Hundreds of egg clutches have been discovered at Auca Mahuevo," reports Dr. Chiappe and his colleges in an article published in the journal Science. They also add that many of the eggs contain bones from small and undeveloped babies-a rare and unexpected find, even in a nesting ground of this size.

Titanosaurs were a group of Sauropod (long-necked, plant-eating) dinosaurs that lumbered our planet during the Cretaceous Period some 65-140 million years ago. One of those, Argentinosaurus,  grew to over 100 feet long, making it unquestionably the largest dinosaur so far unearthed.

In contrast to the unfathomable stature of the adult Titanosaurs, the embryo remains are exceedingly miniscule: the skulls are barely an inch long. The teeth measure a puny 1/8th of an inch long.