Growth rates of pterosaurs once they hatched varied across different groups. In more primitive, long-tailed pterosaurs ("rhamphorhynchoids"), such as "Rhamphorhynchus", the average growth rate during the first year of life was 130% to 173%, slightly faster than the growth rate of alligators. Growth in these species slowed after sexual maturity, and it would have taken more than three years for "Rhamphorhynchus" to attain maximum size. In contrast, the more advanced, large pterodactyloid pterosaurs, such as "Pteranodon", grew to adult size within the first year of life. Additionally, pterodactyloids had "determinate growth", meaning that the animals reached a fixed maximum adult size and stopped growing.