| 词条 | Echinochimaera |
| 释义 |
| name = Echinochimaera | fossil_range = Upper Mississippian, {{Fossil range|318.1|328.3}} | image = Echinochimaera.jpg | regnum = Animalia | phylum = Chordata | classis = Chondrichthyes | subclassis = Holocephali | ordo = Chimaeriformes | familia = Echinochimaeridae | genus = Echinochimaera | genus_authority = Lund, 1977[1] | subdivision_ranks = Species | subdivision = †Echinochimaera meltoni[2] †Echinochimaera snyderi[2] }} Echinochimaera is an extinct genus of fish, it was assigned to the order chimaera by Jack Sepkoski in 2002.[1] The genus' name derives from the Greek εχινό (echino) meaning spiny, and chimaera. SpeciesThe two known Echinochimaera species lived in the Upper Mississippian (Serpukhovian).[3] Fossils of the species were found in the Bear Gulch Limestone in Montana, United States. Both species have rounded bodies and paddle-like tails as well as large pectoral fins, two dorsal fins and a jaw fused to the braincase.[4] The paddle-like tails indicate that E. meltoni was likely not a predator nor a fast swimmer.[5][6] Echinochimaera meltoniE. meltoni was first described by Richard Lund, an Adelphi University palaeontologist,[7] in 1977.[1][3] The fossils found of E. meltoni have shown a great deal of sexual dimorphism, males being found to have a maximum 150mm body length while the maximum body length found in females was only 70mm (juveniles were 13-20mm). In general, the females only grew to about half the size of the males.[5] Males also had four pairs of spikes which may have been used to defend against predators and to identify the fish as male.[6]There was a relative abundance of immature male fossils found, and that together with the significant sexual dimorphism indicate there was extreme sexual selection among the species.[5] Echinochimaera snyderiE. snyderi was described, like E. meltoni, by Richard Lund. It was described in 1988 based on juvenile specimens, all with a body length under 90mm. E. snyderi differs from E. meltoni in fin detail as well as jaw shape and teeth near the front edge of the face rather than a tooth plate, in mature specimens later found its mature size was found to be larger than E. meltoni.[8]References1. ^1 2 {{cite web |url=http://paleodb.org/cgi-bin/bridge.pl?action=checkTaxonInfo&taxon_no=34799&is_real_user=0 |title=The Paleobiology Database |accessdate=2009-09-25}} {{Taxonbar|from=Q3718511}}2. ^1 {{cite web |url=http://sn2000.taxonomy.nl/Taxonomicon/TaxonTree.aspx?id=987645 |title=The Taxonomican: Genus Echinochimaera |accessdate=2009-09-25}} 3. ^1 {{cite web|url=http://www.cas.umt.edu/paleontology/search/details.cfm?catalogno=5371&refer=browse|title=University of Montana Paleontology Center|date=2007-11-01|accessdate=2009-09-26}} 4. ^{{cite web|url=http://school.discoveryeducation.com/schooladventures/prehistoricsharks/gallery2.html|title=Search for Ancient Sharks|publisher=Discovery Education|accessdate=2009-10-11}} 5. ^1 2 {{cite journal|last=Lund|first=Richard|year=1990|title= Chondrichthyan life history styles as revealed by the 320 million years old Mississippian of Montana |journal=Environmental Biology of Fishes|publisher=Springer Netherlands|volume=27|issue=1|pages=1–19|issn=1573-5133|url=http://www.springerlink.com/content/p6t5w168xu814053/|accessdate=2009-09-26|doi=10.1007/BF00004900}} 6. ^1 {{cite web|url=http://www.sju.edu/research/bear_gulch/pages_fish_species/Echinochimaera_meltoni.php|title=Fossil Fishes of Bear Gulch - Echinochimaera meltoni|date=2006-02-01|archiveurl=https://web.archive.org/web/20120212145647/http://www.sju.edu/research/bear_gulch/pages_fish_species/Echinochimaera_meltoni.php|archivedate=2012-02-12|accessdate=2015-12-09}} 7. ^{{cite web|url=http://www.sju.edu/research/bear_gulch/pages_other/other_lund.php|title=Bear Gulch - About Richard Lund|date=2006-11-16|accessdate=2009-09-27|deadurl=yes|archiveurl=https://web.archive.org/web/20100108080608/http://www.sju.edu/research/bear_gulch/pages_other/other_lund.php|archivedate=2010-01-08|df=}} 8. ^{{cite web|url=http://www.sju.edu/research/bear_gulch/pages_fish_species/Echinochimaera_snyderi.php|title=Fossil Fishes of Bear Gulch - Echinochimaera snyderi|accessdate=2009-09-26}} 4 : Carboniferous cartilaginous fish|Prehistoric cartilaginous fish genera|Chimaera|Mississippian fish of North America |
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