Friday, April 15, 2005

Dinosaurs Layed Eggs Like Birds Not Crocodiles

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(A) The pair of eggs sit at the bottom of the fossilised pelvis (B) An egg found inside the female oviraptorosaurian. The blue color of the egg shell fragments is not the original color, though the texture of the shell pieces probably resembles the original texture of the egg.

From New Scientist .
This is incredible. Paleontologist in China have found dino eggs in the body of the mother!

The first dinosaur eggs found complete with shells in the body of the mother has solved the long-standing mystery of how dinosaurs laid their eggs. The evidence shows they laid a clutch in a series of sittings, like birds, rather than all at once like crocodiles and other living reptiles.

Oviraptors are part of the wide-ranging group called theropods, which also includes Tyrannosaurs and the ancestors of birds. Their fossilised nests are well known in China, typically including over a dozen elongated oval eggs in two rings.

Too little is preserved of the new find to identify the particular species, but the newly eggs looked ready to be laid, says Tamaki Sato of the Canadian Museum of Nature in Ottawa.

The best-preserved egg of the find is nearly 20 centimetres long and 6 to 8 cm wide, although somewhat deformed. Sato says the egg's shape and microscopic structures match those of some previously found eggs.

The pair of eggs show the oviraptor developed one egg at a time in each of its two oviducts, most probably laying one pair at a time in the nest, Sato suggests.

That puts it somewhere between the primitive reptilian form of crocodiles and the more advanced form of the birds, consistent with the theory that birds evolved from dinosaurs related to oviraptors.

Gee, sounds like a transitional fossils to me. An yet more eveidence of "macroevolution". With finds like this happening on a regular basis I'm almost starting to feel sorry for the creationists!

More Info

Added later: Pharyngula has a post as well - didn't realize he was doing a post on it but he approaches it from a slightly different angle.