Furcacauda
{{Short description|Genus of jawless fishes}}
{{Automatic taxobox
| fossil_range = {{fossilrange|419.2|393.3}} Lower Devonian{{cite journal
| author = Mark V. H. Wilson
|author2=Michael W. Caldwell
| year = 1993
| title = New Silurian and Devonian fork-tailed 'thelodonts' are jawless vertebrates with stomachs and deep bodies
| journal = Nature
| volume = 361
| issue = 6411
| pages = 442–444
| doi = 10.1038/361442a0
}}
| image = Furcacauda Wiki2.png
| image_caption = Furcacauda fredholmae
| taxon = Furcacauda
| authority = Wilson & Caldwell, 1998
| type_species = Furcacauda heintzae
| type_species_authority =
| subdivision_ranks = Species
| subdivision = *Furcacauda heintzae
- Furcacauda fredholmae
}}
Furcacauda is a genus of thelodontid agnathan from the Lower Devonian of Canada, and is the type genus of the order Furcacaudiformes.{{cite journal |doi=10.1080/02724634.1998.10011031 |last=Wilson |first=Mark V. H. |author2=Caldwell, Michael W. |year=1998 |title=The Furcacaudiformes: A New Order of Jawless Vertebrates With Thelodont Scales, Based On Articulated Silurian and Devonian Fossils From Northern Canada |journal=Journal of Vertebrate Paleontology |volume=18 |issue=1 |pages=10–29 |url=http://www.vertpaleo.org/publications/jvp/18-10-29.cfm |url-status=dead |archiveurl=https://web.archive.org/web/20100618033607/http://www.vertpaleo.org/publications/jvp/18-10-29.cfm |archivedate=2010-06-18 }} Furcacaudiform thelodontids were deep water jawless vertebrates with symmetrical fork and lobed-finned tails and scales smaller than typical loganellid and nikoliviid thelodonti scales. Furcacaudiform thelodonts are noted as having a laterally compressed body, large anterior eyes, slightly posterior, lateral, and vertical to a small mouth, and a condensed curved row of branchial openings (gills) directly posterior to the eyes. Many but not all had laterally paired fins. Wilson and Caldwell also note the presence of a caudal peduncle and a long caudal fin made of two large lobes, one dorsal and one ventral separated by 8 to 14 smaller intermediate lobes, giving the appearance of a striated half-moon shaped tail resembling the tail of a heterostracan. A large square cavity within the gut connecting a small intestine to an anal opening lead many to believe that it is this genus that exhibits the first vertebrate stomach. According
to Wilson and Caldwell their discovery, based on sediment infillings of fossils of the Furcacauda heintze, gives credence to the evolutionary development of stomach before jaws.
Gallery of species
Image:Furcacauda_heintzae.png|Furcacauda heintzae
Image:Furcacauda_fredholmae.png|Furcacauda fredholmae
{{Portal|Paleontology}}
References
{{Reflist}}
External links
- {{Commons category-inline|Furcacauda}}
- [http://taxonomicon.taxonomy.nl/TaxonTree.aspx?id=146819 The Taxonomicon. (2004–2009)] Retrieved November 6, 2009.
{{Thelodonti}}
{{Taxonbar|from=Q5509484}}