These are fossilized scutes from a crocodile, an aquatic reptile. A scute is the bony external plate found on the skin of crocodiles and other reptiles. Each fossil measures around 2.5 cm x 2 cm x 0.5 cm in size or less.
- Catalog Number:
- 401594
- Object/Specimen Description:
- Specimen Count:
- 11
- Collector:
- A. Bolton
- Locality:
- US High Plains and Rocky Mountains (ID, MT, ND, SD, WY, CO)
- Collecting Date:
- 24 Jul 2014
- Collecting Locality:
- North America, United States, Montana, Fallon County
- Cabinet:
- 07
- Drawer/Shelf:
- 07
- Special Instructions:
- Ask a staff person for assistance
- Upper Level Taxonomy:
- Animalia, Chordata, Vertebrata, Tetrapoda, Reptilia, Crocodilia, Crocodylidae
Reptiles first appeared on Earth about 300 million years ago (during the Pennsylvanian). Before then, all back-boned animals (vertebrates) were tied to the water, living in or near swamps. Their eggs were laid underwater. A set of gradual adaptations, such as thicker, scaly skin, allowed life on land to emerge. The biggest change was the development of an egg containing layers of membranes (amniotic membranes) to retain water, supply food, and store waste for an embryo. Two further innovations – the eggshell and internal fertilization – marked the first reptiles. Fertilization inside the female and shelled, amniotic eggs freed reptiles from aquatic life. They diversified into dinosaurs, crocodiles, lizards, snakes, turtles, tuataras, and birds as they colonized a variety of land habitats. For more than 100 million years, reptiles dominated the Earth. The largest reptiles were wiped out in the extinction event at the end of the Mesozoic, but their smaller descendants live on today.