Guildfordia yoka Jousseaume, 1888 - yoka star turban snail shell, apical view (8.3 cm across), modern (latest Holocene).

The turbinids are common, tropical, herbivorous snails. One of the more visually intriguing turbinids is the star turban. This snail tends to inhabit unconsolidated, fine-grained substrates in moderately deep, low-energy settings. The long spines projecting from the final whorl's keel are throught to help prevent the snail from sinking (a common problem among epifaunal, benthic invertebrates throughout geologic history) and to help prevent predators from easily flipping the shell over.

Classification: Animalia, Mollusca, Gastropoda, Archaeogastropoda, Trochoidea, Turbinidae

The gastropods (snails & slugs) are a group of molluscs that occupy marine, freshwater, and terrestrial environments. Most gastropods have a calcareous external shell (the snails). Some lack a shell completely, or have reduced internal shells (the slugs & sea slugs & pteropods). Most members of the Gastropoda are marine. Most marine snails are herbivores (algae grazers) or predators/carnivores.