Question about growth patterns

HAHAHA I love this! What a cute picture! Duncan had some pretty big ears and paws when we got him @ 8.5 weeks (his dad was 90 something lbs so we figured he was going to be a big boy) and different parts of him grew at different rates that is for sure - he was such a gangly teenager with super long legs for awhile and a small head compared to his body ... then his head caught up a little (although it is still catching up) ... then he filled out some but stopped around 60ish lbs in September and just recently within the past month or two gained some more weight after being around 60lbs for 4-5 months straight - he definitely looked like a dorky gangly teenager for awhile, but that was probably my favorite phase of all now when I look back at it! he had these long legs and hadn't filled out yet and was so clumsy and goofy! Now at 13.5 months old he is about 70-72lbs and I have noticed recently his neck growing and his head growing!

Here are a couple pics of him at 8.5 weeks with the big ears and then a couple from when he was about 7months and in the goofy growing stage!