Twenty-six species of terrestrial gastropods have been identified, primarily land snails and slugs.

The estimate of 85, 000 molluscs includes 24, 000 described species of terrestrial gastropods.

Some of the more familiar and better-known gastropods are terrestrial gastropods ( the land snails and slugs ) and some live in freshwater, but more than two thirds of all named species live in a marine environment.

Almost all marine gastropods breathe with a gill, but many freshwater species, and the majority of terrestrial species, have a pallial lung.

One of the earliest known terrestrial ( land-dwelling ) gastropods is Maturipupa, which is found in the Coal Measures of the Carboniferous period in Europe, but relatives of the modern land snails are rare before the Cretaceous period, when the familiar Helix first appeared.

Tracks made by terrestrial gastropods with their radulas, scraping green algae from a surface inside a greenhouse

This is in contrast to the bivalves which were able to adapt to brackish water and freshwater, and the gastropods which were able to make successful transitions to freshwater and terrestrial environments.

Animal remains include terrestrial gastropods and mastodons.

At the beginning in the mid-1700s the generic name Helix had been used for almost all terrestrial gastropods, later this was restricted to species with helicoid habitus, including zonitids and other groups.

There are known 183 species and subspecies of terrestrial gastropods from Costa Rica and numerous freshwater gastropods and bivalves.

Littorinimorpha is a large clade of gastropods within Hypsogastropoda consisting primarily of marine species, but also aquatic and terrestrial species as well.

Most terrestrial caecilians that lay eggs do so in burrows or moist places on land near bodies of water.

A team of biologists convened by the World Wide Fund for Nature ( WWF ) developed an ecological land classification system that identified fourteen biomes, called major habitat types, and further divided the world's land area into 867 terrestrial ecoregions.

Anthropogenic biomes provide an alternative view of the terrestrial biosphere based on global patterns of sustained direct human interaction with ecosystems, including agriculture, human settlements, urbanization, forestry and other uses of land.

Amphibians were the dominant land vertebrates, of which one branch would eventually evolve into reptiles, the first fully terrestrial vertebrates.

Since large vertebrate terrestrial herbivores had not yet appeared, free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents.

LORAN ( LOng RAnge Navigation ) is a terrestrial radio navigation system which enables ships and aircraft to determine their position and speed from low frequency radio signals transmitted by fixed land based radio beacons, using a receiver unit.

Some of these mammals would evolve into large forms that would dominate the land, while others would become capable of living in marine, specialized terrestrial, and airborne environments.

Rather, they concluded that azhdarchids were more likely terrestrial stalkers, similar to modern storks, and probably hunted small vertebrates on land or in small streams.

Although many populated land locations on the planet now have terrestrial communications facilities ( microwave, fiber-optic ), even undersea, with more than sufficient capacity, telephony and Internet access is still available only via satellite in many places in Africa, Latin America, and Asia, as well as isolated locations that have no terrestrial facilities, such as Canada's Arctic islands, Antarctica, the far reaches of Alaska and Greenland, and ships at sea.

The majority of crustaceans are aquatic, living in either marine or freshwater environments, but a few groups have adapted to life on land, such as terrestrial crabs, terrestrial hermit crabs, and woodlice.

Freshwater ecoregions are distinct from terrestrial ecoregions, which identify biotic communities of the land, and marine ecoregions, which are biotic communities of the oceans.

The Nearctic is one of the nine terrestrial ecozones dividing the Earth's land surface.

For example, mutualistic interactions are vital for terrestrial ecosystem function as more than 48 % of land plants rely on mycorrhizal relationships with fungi to provide them with inorganic compounds and trace elements.

For example, for submerged terrestrial sites or inland water, identification of pollen samples from sedimentary or silt layers can provide information on the plants growing on surrounding land and hence on the nature of the landscape.

Snail is a common name applied most often to land snails, terrestrial pulmonate gastropod mollusks.

Global regions are those areas of the planet that are easily distinguishable from space, and are therefore clearly distinguished by the two basic terrestrial environments, land and water.

In contrast to the underlying sediments of the Ludlow Series which were deposited in a shallow warm sea some 400 million years ago, the Ludlow Bone Bed represents terrestrial ( land ) conditions and thus a fundamental change in the landscape.

Though technically incorrect, the definition is sometimes widened to include the study of terrestrial animals in other arthropod groups or other phyla, such as arachnids, myriapods, earthworms, land snails, and

These vocal, social animals are somewhat better adapted to terrestrial habitats, with rear flippers that can turn forward so they can move on all fours on land.

Terrestrial animals that can only produce ammonia would have to drink constantly, making a life on land impossible ( a few exceptions exist, as some terrestrial woodlice can excrete their nitrogenous waste as ammonia gas ).

Initially making only tentative forays onto land, tetrapods adapted to terrestrial environments over time and spent longer periods away from the water, while also spending a longer part of their juvenile stage on land before returning to the water for the rest of their life.

Although many people are familiar with terrestrial snails, they are in the minority.

In birds, reptiles, and terrestrial snails, metabolic ammonium is converted into uric acid, which is solid and can therefore be excreted with minimal water loss.

Helix is a genus of large air-breathing land snails, terrestrial pulmonate gastropod molluscs.

Since snails in the genus Helix are terrestrial rather than fresh-water or marine, they have developed a simple lung for respiration.

The diet of these rails is omnivorous, being known to include a wide variety of plant and animal matter, including seeds, leaves and fruits of both aquatic and terrestrial plants, as well as insects, frogs, snails, spiders, earthworms and fish.

Powelliphanta, common name the amber snails, is a genus of large, air-breathing, carnivorous land snails, terrestrial pulmonate gastropod molluscs in the family Rhytididae.

These birds mainly eat terrestrial arthropods and snails, and also include fruit in their diet during winter.

Achatinidae ( New Latin, from Greek " agate ") is a family of medium to large sized tropical land snails, terrestrial pulmonate gastropod mollusks from Africa.

A wide variety of food items taken, including both aquatic and terrestrial larval and adult insects, other arthropods ( especially spiders ), and snails.

Heterobranchia, the heterobranchs ( meaning " different-gilled snails "), is a taxonomic clade of snails and slugs, which includes species from the sea, the land and freshwater ; marine, aquatic and terrestrial gastropod mollusks.

Diet varies widely, with examples including Tornierella, who specialize on snails, and Afrixalus fornasinii, the only terrestrial frog known to prey on eggs of other species of anurans.

* Godwinia ( gastropod ), a genus of terrestrial snails from family Oxychilidae native to Hawaii

Zebrina is a genus of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Enidae.

* Arinia simplex, a species of small land snails with an operculum, terrestrial gastropod mollusks in the family Diplommatinidae

Ramsdenia is a genus of land snails with an operculum, terrestrial gastropod mollusks in the family Pomatiidae.