Willem Vrolik, a Dutch anatomist and paleontologist who is a pioneer in the field of vertebrate teratology, published teratological works oncyclopia, thepathogenesisof congenital anomalies, and a treatise onconjoined twins as well as Handboek der ziektekundige ontleedkunde (Handbook of pathological anatomy); however, these were later on stopped in production.
Willem Vrolik (29 April 1801  22 December 1863) was a Dutch anatomist and pathologist who was a native of Amsterdam. 
