"By looking at growth rings in the bones, the team found that Whatcheeria deltae got big fast and then slowed to a more leisurely but steady growth rate. All of the nine specimens they studied were older juveniles and young adults, Otoo said, so it seems that the animals bulked up to around 3.3 feet (1 meter) in length as they neared sexual maturity and then grew larger more slowly in later adulthood. "
https://www.livescience.com/tetrapod-predator-growth
Original article:
https://www.nature.com/articles/s42003-022-04079-0