Fossilized Eggs of Bird-like Dinosaur Discovered in Patagonia
Posted on April 10, 2012
A 70 million-year-old pocket of fossilized bones and eggs of Bonapartenykus, an enigmatic birdlike dinosaur, has been discovered in Patagonia. The creature belongs to the Alvarezsauridae family of small bipedal feathered dinosaurs known from Asia, North and South America. These dinosaurs had a bird-like skull, jaws filled with tiny teeth, robust but abbreviated forearms and one of their manual digits that developed massive phalanges, including an enormous claw.
The dinosaur discovered is one of the largest members (2.6 meters) of the Alvarezsauridae family. It was first discovered by Dr. Powell, but has now been described and named Bonapartenykus ultimus in honor of Dr. Jose Bonaparte who 1991 discovered the first alvarezsaurid in Patagonia.
The Argentine-Swedish research team that found the fossilized eggs and bones say the dinosaur represents the latest survivor of its kind from Gondwana, the southern landmass in the Mesozoic Era. Dr. Martin Kundrat, a dinosaur expert from the group of Professor Per Erik Ahlberg at Uppsala University, says, the find shows that basal alvarezsaurids persisted in South America until Latest Cretaceous times.
The researchers say two eggs found together with the bones during the expedition might have been inside the oviducts of the Bonapartenykus female when the animal perished. Numerous eggshell fragments later found show considerable calcite resorption of the inner eggshell layer, which suggest that at least some of the eggs were incubated and contained embryos at an advanced stage of their development.
Kundrat analyyed the eggshells using electron scanning microscopy and found unusual fossilized objects inside of the pneumatic canal of the eggshells, which he says is the first evidence of fungal contamination of dinosaur eggs.