species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
land snail
A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. ''Land snail'' is the common name for terrestrial molluscs, terrestrial gastropod mollusks that have gastropod shell, shel ...
, a
terrestrial
Terrestrial refers to things related to land or the planet Earth, as opposed to extraterrestrial.
Terrestrial may also refer to:
* Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on o ...
pulmonate
Pulmonata or pulmonates is an informal group (previously an order, and before that, a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group inclu ...
gastropod
Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda ().
This class comprises snails and slugs from saltwater, freshwater, and fro ...
mollusc
Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...
in the family
Bothriembryontidae
Bothriembryontidae is a family of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the superfamily Orthalicoidea.
Taxonomy
This family has been named Placostylidae and had no subfamilies (according to the taxonomy of ...
. MolluscaBase eds. (2022). MolluscaBase. Archaeostylus Brook & Hayward, 2022 †. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=1582263 on 2022-06-19
This species is the typetaxon and only member of the monotypic genus ''Archaeostylus'', found in
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58New Zealand
New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...
. ''Archaeostylus'' is thought to represent an extinct, sister lineage to the modern flax snail species currently living in New Zealand, and is not a direct ancestor.
Description
''Archaeostylus manukauensis'' has a large long
shell
Shell may refer to:
Architecture and design
* Shell (structure), a thin structure
** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses
Science Biology
* Seashell, a hard outer layer of a marine ani ...
that is thin, elongate-conical, and slightly dorso-ventrally compressed. Unlike other genera of flax snail, ''A. manukauensis'' lacks a thickened outer lip surrounding its aperture, and instead possesses a thin peristome with a collabral callus ridge on the palatal wall. In all of the specimens studied, a broad, shelf-like callus ridge extends from top of aperture almost to the base of the columella, bearing a flattened, irregularly rounded, tongue-like projection on its upper part.
Distribution and habitat
Fossils
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
of this extinct land snail species are known only from the Late
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Waipipian (~3.6–3.0 Ma) Māngere Shellbed, located approximately 30 m below the suburb of Mangere,
Auckland
Auckland ( ; ) is a large metropolitan city in the North Island of New Zealand. It has an urban population of about It is located in the greater Auckland Region, the area governed by Auckland Council, which includes outlying rural areas and ...
. It is currently regarded as one of the two oldest known flax snails species represented in the fossil record, along with a single specimen of another species ('' Maoristylus pliocenica'') also from the Māngere Shellbed. ''A. manukauensis'' presumably inhabited lowland broadleaf forest and scrub habitats, similar to recent species of flax snail. Its buoyant shells likely ended up in marine shellbed deposits after being washed to the coast in streams, or in run-off after heavy rainfall.