About 70-million-year-old fossilized bones and eggs of alvarezsauridae, an enigmatic family of small bird-like dinosaur, have been discovered in Patagonia, South America, a study published in the online edition of the scientific journal Cretaceous Research claims.

Scientists found two eggs preserved near articulated bones of the dinosaur’s hindlimb, the AlphaGalileo Foundation reported on behalf of the journal on Tuesday.

“This is the first time the eggs are found in a close proximity to skeletal remains of an alvarezsaurid dinosaur,” Dr. Martin Kundrat, dinosaur expert at Sweden’s Uppsala University said.

Kundrat along with Fernando Novas, F. Agnolin and J. Powell from Museo Argentino de Ciencias Naturales found the eggs in December 2010 as part of the first Argentine-Swedish Dinosaur expedition and collaboration.

Most of the eggshell fragments of the dinosaurs discovered so far suggest that either they were incubated or contained embryos in an advanced stage of development.

However, the two eggs found together with the fossilized bones of alvarezsaurid dinosaur during the expedition did not belong to any known category of the eggshell microstructure-based taxonomy, according to Kundrat, who analyzed the eggshells.

He said that the eggs might have been inside the oviducts of the female dinosaur when she died.

Kundrat also found the first evidence of fungal contamination of dinosaur eggs.

“During inspection of the shell samples using the electron scanning microscopy I observed unusual fossilized objects inside of the pneumatic canal of the eggshells. It turned out to be the first evidence of fungal contamination of dinosaur eggs,” he said.

Alvarezsaurid were long-legged, but small dinosaurs, found in South America, North America and Asia. They varied in length from 0.5 to 2 meters but the fossil found in Patagonia is said to be that of a 2.6 meters long alvarezsaurid dinosaur, the research team said.