How did pterosaurs fossilize?
Everything we know about pterosaurs comes from examination of their fossil remains. Not all animals become fossils, and in fact it is quite rare and requires special conditions. Pterosaurs are especially rare fossils because their hollow bones were delicate: over 90% of pterosaur fossils come from just a handful of lake and shallow sea deposits that allowed for their preservation.
These sites include the Solnhofen Limestone in southern Germany, the Araripe Basin in northeastern Brazil, and several different locations in northeastern China. Follow along with this individual of Pterodactylus, from the Upper Jurassic Solnhofen Limestone, on its journey from living organism to one of the most important fossils in the history of paleontology.
- 1
Death
After this Pterodactylus died it sank to the stagnant, oxygen-poor bottom of a shallow sea in Germany. Many fossils show signs of being scavenged, but this is not always the case.
- 2
Burial and decomposition
The body was buried under sediments and the soft tissues underwent decomposition. Because of the lack of oxygen, decomposition was incomplete, and the bones and teeth remained.
- 3
Diagenesis
The body was buried deeper and flattened. Minerals replaced tough organic matter in bones and teeth. The remains are now fossils, and the surrounding sediment has become rock.
- 4
Discovery
The fossil was slowly brought to the surface of the Earth. This Pterodactylus specimen was discovered in about 1770 and was the first pterosaur ever studied scientifically, described by Cosimo Collini in 1784.
