1. Plural of hydrocast; casts or molds made by pouring liquid material (such as plaster or resin) into a mold to create a replica or reproduction, often used in paleontology and geology to preserve fossil impressions.
Usage: technical; paleontology; geology

Examples

• The museum displayed hydrocasts of ancient ammonite fossils alongside the original specimens.
• Paleontologists created hydrocasts to preserve detailed impressions of the dinosaur footprints.
• These hydrocasts allow researchers to study fossil structures without damaging the originals.
• The hydrocasts were made using a specialized plaster compound to capture fine details.
• Students examined the hydrocasts to learn about extinct marine organisms.