July 4:

• 1899 - Arthur Coggeshall discovered the type specimen of Diplodocus carnegii near Sheep Creek, Wyoming, USA. The specimen is now curated by the Carnegie Museum of Natural History, whose exhibit hall had to be expanded to make room for it.
• 1942 - Marcellin Boule died.
• 1946 - Othenio Abel died in Mondsee, Austria at age 71.