Gastropoda

Gastropoda Cuvier, 1797

Gastropods

Taxon overview

The Gastropoda or gastropods, more commonly known as snails and slugs, are a large taxonomic class within the phylum Mollusca.
Snails are distinguished by an anatomical process known as torsion, where the visceral mass of the animal rotates 180° to one side during development, such that the anus is situated more or less above the head. This process is unrelated to the coiling of the shell, which is a separate phenomenon. Torsion is present in all gastropods, but the opisthobranch gastropods are secondarily de-torted to various degrees.
Gastropods typically have a well-defined head with two or four sensory tentacles with eyes, and a ventral foot, which gives them their name (Greek gaster, stomach, and poda, feet). The larval shell of a gastropod is called a protoconch.
The class Gastropoda contains a vast total of named species, second only to the insects in overall number. The fossil history of this class goes back to the early Cambrian.

Selection of related publications
Toom, U., Vinn, O., Hints, O. 2019. Ordovician and Silurian ichnofossils from carbonate facies in Estonia: A collection-based review. Palaeoworld 28, 1-2, 123-144. DOI:10.1016/j.palwor.2018.07.001
Kröger, B., Aubrechtová, M. 2018. Cephalopods from reef limestone of the Vasalemma Formation, northern Estonia (latest Sandbian, Upper Ordovician) and the establishment of a local warm-water fauna. Journal of Systematic Palaeontology 16, 10, 799-839. DOI:10.1080/14772019.2017.1347212
Isakar, M. 2017. Huvitav leid: kivistunud "kihv". Eesti Loodus , 3, 47.
Vinn, O., Wilson, M. A. 2013. Silurian cornulitids of Estonia (Baltica). Carnets de Géologie , A09, 357-367. DOI:10.4267/2042/53034
Ebbestad, J. O. R., Lindström, A., Peel, J. S. 2009. Predation on bellerophontiform molluscs in the Palaeozoic. Lethaia 42, 4, 469-485. DOI:10.1111/j.1502-3931.2009.00167.x
Frisk, Ǻ. M., Ebbestad, J. O. R. 2007. Paragastropoda, Tergomya and Gastropoda (Mollusca) from the Upper Ordovician Dalby Limestone, Sweden. GFF 129, 2, 83-99. DOI:10.1080/11035890701292083
Ebbestad, J. O. R., Högström, A. E. S. 2007. Locality descriptions, the Siljan District. WOGOGOB 2007. Field guide and Abstracts. Eds: Ebbestad, Wickström & Högström , pp. 52-58.
Isakar, M., Ebbestad, J. O. R. 2000. Bucania (Gastropoda) from the Ordovician of Estonia. Paläontologische Zeitschrift 74, 1-2, 51-68. DOI:10.1007/BF02987951
Isakar, M., Ebbestad, J. O. R., Peel, J. S. 1999. Homeomorphic gastropods from the Silurian of Norway, Estonia and Bohemia. Norsk Geologisk Tidsskrift 79, 4, 281-288. DOI:10.1080/002919699433717
Isakar, M. 1995. The platyceratacean gastropod Cyclonema (Cyclonema) hiiumaa Teichert, 1928 from the Llandovery (Silurian) of Estonia. Proceedings of the Estonian Academy of Sciences. Geology 44, 3, 184-187.
Isakar, M. 1991. Harjuan (Late Ordovician) new Bivalves and a new Gastropod from North Estonia. Acta et Comentationes Universitatis Tartuensis 934, 12, 43-60. Töid geoloogia alalt, XII. Eesti Ordoviitsiumi paleontoloogia ja stratigraafia, pp. 43-60.
Isakar, M. 1990. Bivalvia and Gastropoda. Field Meeting Estonia 1990. An Excursion Guidebook, pp. 64-65.
Kisselev, G. N., Sinitsyna, I. N., Isakar, M. A., Mironova, M. G., Saladzhius, V. Y. 1990. Atlas of Upper Ordovician and Silurian molluscs from the nort-western part of East-European platform.
Rõõmusoks, A. 1970. Stratigraphy of the Viruan Series (Middle Ordovician) in Northern Estonia, I.
Lõokene, E. 1961. The Geology of Travertine in the Estonian S. S. R.. Trudy Instituta geologii AN ESSR 7, 135-143. ENSV Teaduste Akadeemia Geoloogia Instituudi Uurimused VII. 1961, pp. 135-143.
Erisalu, E. 1959. Välipäevik nr 5: geoloogiline kaardistamine Kirde-Eestis.
Öpik, A. 1930. Beiträge zur Kenntnis der Kukruse-(C2-C3-)Stufe in Eesti. IV. Tartu Ülikooli Geoloogia Instituudi Toimetused , 24, 1-34.
Koken, E. & Perner, J. 1925. Die Gastropoden des baltischen Untersilurs.
Bekker, H. 1925. Lühike ülevaade Eesti geoloogiast (Eozoiline ja paleozoiline ladekond). Eesti Loodus. Äratrükk koguteosest "Eesti", pp. 31-61.
Bekker, H. 1924. Devon Irboska ümbruses: stratigraafia, fauna ja paleogeograafia. Eesti Loodusteaduse Arhiiv 10, 1, 1-55.
Koken, E. 1897. Die Gastropoden des baltischen Untersilurs. Bull. Sci. Acad. Imp. Sci. Saint-Petersbourg 7, 2, 97-214.
Koken, E. 1896. Die Leitfossilien. Ein Handbuch für den Unterricht und für das Bestimmen von Versteinerungen.
Lindström, G. 1884. On the Silurian Gastropoda and Pteropoda of Gotland. Kungliga Svenska Vetenskapsakademiens Handlingar 19, 6, 1-250.
Eichwald, E. 1861. Paleontologiâ Rossii. Drevnij period. II. Fauna grauvakkovoj, gornoizvestkovoj i medistoslancevatoj formacij Rossii.
Schmidt, Fr. 1858. Untersuchungen über die Silurische Formation von Ehstland, Nord-Livland und Oesel. Archiv für die Naturkunde Liv-, Ehst- und Kurlands 2, 1, 1-249.