Quetzalcoatlus northropi- BIO203
Reproduction
When people think of reproduction between reptiles, they usually think of a male and female coming together to form a zygote, which will eventually grow up to be a full grown adult offspring. Before evidence was collected, many scientists presumed that pterosaurs reproduced like birds. Hatching young in rigid shells, and then caring and providing for them until they could manage on their own(Juchang, 2011). Yes, pterosaurs reproduce in this way, but what is interesting is even though pterosaurs are large, they produce very small eggs that are buried in the ground like that of a reptile. Direct evidence for this mode of reproduction was found in the fossil record of a Darwinopterus, a pterosaur found in China with an egg (Juchang, 2011). The fossilized pterosaur gave scientists an insight into what different the characteristics of different genders were, and what the egg or embryo was composed of. Females, generally had a very large pelvis for reproduction, and no crest, while, males had a small pelvis, and a large cranial crest (Juchang, 2011). Also, scientists found that the pterosaur egg was made more out of a parchment like that of a reptile, which would allow it to be buried. Burying eggs would be very advantageous to the pterosaur because it would allow the parent to not have to supply the egg with any of her nutrients or time. What is strange is, if pterosaurs buried their eggs, why would they be so small? Small eggs normally can’t withstand the environment and provide enough nutrients and protection for the embryo inside. So, with pterosaur eggs being so small, where did they get their nutrients for growth? Well, since they were buried in the ground, the egg was able to absorb oxygen from the ground and release carbon dioxide, and retrieve nutrients form the egg yolk (Juchang, 2011). This mode of reproduction would be extremely beneficial to pterosaurs , especially females, because they don’t have to expend any of their energy to care for their young. However, pterosaurs probably had to bring food to their young for the beginning stages of life, it is still an advantageous way of reproduction because the young were assumed to be able to fly and be on their own after a short period of time with their parents (Unwin, 2008).