It heralded the first great phase of development in science and architecture; hieroglyphs were developed and the first great building phase took place.
The emergence of hieroglyphs, while a curiosity to anthropologists, is not considered to have any connection to the overall development in science and architecture. 
mnli hypothesis: The emergence of hieroglyphs, while a curiosity to anthropologists, is not considered to have any connection to the overall development in science and architecture.  premise: It heralded the first great phase of development in science and architecture; hieroglyphs were developed and the first great building phase took place.