Dr. Leidy had a long and distinguished career as a medical doctor, paleontologist and general scientist in the Philadelphia area. He served with distinction at the University of Pennsylvania, the Academy of Natural Sciences, and the Wagner Free Institute of Science.

He was a highly respected Microscopist in the early years when the microscope was found to be the key to unlocking the secrets of nature, especially in the medical science. At the age of 35, he was one of the 23 medical doctors and 4 scientists who organized the original study group that evolved into the society that now bears his name.

In addition to his many accomplishments in the medical fields, chiefly in anatomy, he won distinction and lasting fame as a Vertebrate Paleontologist at the time when dinosaurs were first being excavated in the United States. Fossil deposits found in New Jersey and the western states provided the opportunity for him to lay the foundation of American paleontology by describing and naming these extinct creatures. His knowledge of comparative anatomy was the key to his achievements in the field. His student Edward Drinker Cope, continued after Dr. Leidy’s passing.