Complex sentence: Ponder was the principal research scientist in the malacology section of the Australian Museum, Sydney, Australia and helped to build up the museum's mollusc collection so that it became one of the most extensive of its kind in the world.
Split into simpler sentences: Ponder was the principal research scientist in the malacology section of the Australian Museum, Sydney, Australia. He helped to build up the museum's mollusc collection so that it became one of the most extensive of its kind in the world.