Complex sentence: However, she eventually became the managing editor of the "Catalog of Foraminifera" she had previously worked on at the American Museum of Natural History in 1946, and also held a position as an assistant curator to Micropaleontology.
Split into simpler sentences: However, she eventually became the managing editor of the "Catalog of Foraminifera", which she had previously worked on at the American Museum of Natural History in 1946. She also held a position as an assistant curator to Micropaleontology.