Have you ever wondered what a triceratops used its horns for? Ever pondered why a saber-toothed cat needed saber teeth? Why some creatures go extinct when others don’t?

Learn the answers to these questions and more as Don "The Fossil Guy" Johnson returns to the University of Iowa Museum of Natural History in April with educational programs at 2 p.m. on Saturday afternoons.

The free public programs, held in Macbride Auditorium, feature a 30-minute talk by Johnson, a local amateur paleontologist, followed by a hands-on Q&A session with his collection of fossils and replicas. Presentations are geared toward elementary-age children.

Dates and programs are as follows:

April 12: “Veggiesauruses Large & Small.” Learn about a variety of plant-eating dinosaurs during this program. Also see and touch real fossil bones, teeth, claws, and even an egg from a number of different plant-eating dinosaurs. Examine dinosaur fossil replicas, including duckbill skin and jaws and a triceratops horn.

April 19: “Chewing up the Ice Age.” Learn about Ice Age mammals as Johnson focuses on the remains of giant ground sloths and mammoths recovered by crews from the UI Museum of Natural History. See and touch mineralized bones of Ice Age creatures, including horses, bison, deer, polecats and cave bears. View a replica skull of the famous dire wolf from the La Brea Tar Pits in California. Artifacts of Paleo-Indians will be used to help re-create the Ice Age world of North America.

April 26: “Climate, Extinction and the Fossil Record.” What role did climate change have in some of the great extinction events in the fossil record? What other causes of extinction need to be considered? See and touch many fossils of trilobites, blastoids, ammonites, Late Cretaceous dinosaurs and Ice Age mammals as Johnson examines three major extinction events: the Permian-Triassic (252 million years ago), the Cretaceous-Paleogene (66 million years ago) and the Late Pleistocene (ending 11,700 years ago).

Individuals with disabilities are encouraged to attend all UI-sponsored events. If you are a person with a disability who requires a reasonable accommodation in order to participate in any of these programs, contact the Pentacrest Museums in advance at 319-335-2010.

For more information on the Museum of Natural History or Fossil Guy programs, call 319-335-0606 or visit the Museum of Natural History website.