I’m currently working my way through the Australopithecus sediba articles mentioned in the previous post. In the meantime, in wandering around the internet there are a number of things make a science story jump out and say “write about me!” First, if it uses a methodology that answers the question “how do we know?” Second, if it is about life history. Third, if it combines the first two with dinosaurs.
Science Daily (World’s Oldest Dinosaur Embryo Bonebed Yields Organic Remains) points us to a research paper that has all three (plus more). The paper, Embryology of Early Jurassic dinosaur from China with evidence of preserved organic remains, was published in Nature. I don’t have access to the Nature paper so I will have to rely on the Science Daily press release.
From Science Daily:
The bones represent about 20 embryonic individuals of the long-necked sauropodomorph Lufengosaurus, the most common dinosaur in the region during the Early Jurassic period. An adult Lufengosaurus was approximately eight metres long.
The disarticulated bones probably came from several nests containing dinosaurs at various embryonic stages, giving Reisz’s team the rare opportunity to study ongoing growth patterns. Dinosaur embryos are more commonly found in single nests or partial nests, which offer only a snapshot of one developmental stage.
First, and this is the how do we know part, in modern birds muscle activation – which causes them to twitch – has a role in shaping the anatomy of the skeleton embryologicaly. This causes some bones to exhibit asymmetric radial growth and this is seen in Lufengosaurus so that we can say that we can say that Lufengosaurus displayed a similar development pattern to birds. Second, the research indicated that Lufengosaurus had a fast growth rate (which could be a predator avoidance strategy or have implications for sexual maturity in Lufengosaurus.
A couple of other interesting things, both from Science Daily:
The Taiwanese members of the team also discovered organic material inside the embryonic bones. Using precisely targeted infrared spectroscopy, they conducted chemical analyses of the dinosaur bone and found evidence of what Reisz says may be collagen fibres. Collagen is a protein characteristically found in bone.
Only about one square metre of the bonebed has been excavated to date, but this small area also yielded pieces of eggshell, the oldest known for any terrestrial vertebrate. Reisz says this is the first time that even fragments of such delicate dinosaur eggshells, less than 100 microns thick, have been found in good condition.