However it is very likely that it would have grown more slowly were it to have reached adulthood, as previous research on the growth rings of early birds (similar to those in trees) has indicated that, unlike adult, modern birds, primitive birds may have matured slowly and experienced seasonal growth cycles.
(primitive birds; may have matured slowly; ) (primitive birds; experienced; seasonal growth cycles) (it; were; it to have reached adulthood) Context(it were,List([31, 67))):(it; to have reached; adulthood)
it were,List([31, 67))
primitive birds primitive birds it it
may have matured slowly experienced were to have reached
seasonal growth cycles
it to have reached adulthood
adulthood