| 词条 | Valdiviathyris |
| 释义 |
| fossil_range = {{Fossil range|Silurian|Recent}} | taxon = Valdiviathyris | authority = Helmcke, 1940 [1] | type_species = Valdiviathyris quenstedti | type_species_authority = Helmcke, 1940 [1] | subdivision_ranks = Species | subdivision ={{Specieslist |V. quenstedti|Helmcke, 1940 Late Eocene to recent |V. bicornis|Holmer, Popov & Bassett, 2013 Silurian }} }}Valdiviathyris is a genus of craniate brachiopods that has changed little since the Silurian, from when fossils are known.[2] The extant species V. quenstedti is known from the late Eocene.[3][4] It was initially known only from the holotype collected from the southern Indian Ocean, near Île Saint-Paul, at a depth of {{convert|672|m}}.[4] The specimen is considered to be adolescent and has a thin (0.1 mm thick) calcareous dorsal valve. This has an irregular conical shape, with the tip (or apex) not coinciding with the middle, and is on the outside only adorned by growth lines. On the inside it has pits (or punctae) that branch into four or five canals further to the outside. More recent specimens have been found near New Zealand. As long as no fossils of Vadiviathyris are found dating between the Silurian and the Eocene, this genus can be regarded a Lazarus taxon.[2] References1. ^1 {{cite WoRMS |author=Christian Emig |year=2013 |title=Valdiviathyris Helmcke, 1940 |db=Brachiopoda |id=235167 |accessdate=October 8, 2013}} {{Taxonbar|from=Q4540193}}{{brachiopod-stub}}2. ^1 {{cite journal|first1= Lars E.|last1= Holmer|first2= Leonid|last2= Popov|first3= Michael G.|last3= Bassett|year= 2013|title= Silurian Craniide brachiopods from Gotland|journal= Palaeontology|volume= 56|issue= 5|pages= 1029–1044|url= https://www.academia.edu/4625326/SILURIAN_CRANIIDE_BRACHIOPODS_FROM_GOTLAND}} 3. ^{{cite journal |author=Jeffrey H. Robinson & Daphne E. Lee |year=2007 |title=The recent and Paleogene craniid brachiopod, Valdiviathyris quenstedti Helmcke, 1940 |journal=Systematics and Biodiversity |volume=5 |issue=1 |pages=123–131 |doi=10.1017/S1477200006002179}} 4. ^1 {{cite journal |author=A. J. Rowell |year=1961 |title=The brachiopod genus Valdiviathyris Helmcke, 1940 |journal=Palaeontology |volume=4 |issue=4 |pages=542–545 |url=http://palaeontology.palass-pubs.org/pdf/Vol%204/Pages%20542-545.pdf |format=PDF}} 5 : Craniata|Brachiopod genera|Living fossils|Extant Silurian first appearances|Pridoli genus first appearances |
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