| 词条 | Amaltheus |
| 释义 |
|image = Amaltheus180910.jpg |fossil_range = {{fossil range|Pliensbachian|ref=[1]}} |taxon = Amaltheus |authority = de Montfort, 1808 |subdivision_ranks = Subgenera |subdivision = see text }}Amaltheus is an oxyconic ammonite with a fairly open umbilicus, serrated keel, and slightly sigmoidal ribs from the Lower Jurassic, many of which are strigate. Amaltheus, named by de Montfort, 1808, is indicative of the upper Pliensbachian stage in Europe, north Africa, Caucasus, Siberia, N. Alaska, Canada, Oregon, and possibly Honduras; and is the type for the Amaltheidae and a member of the Eoderoceratoidea.[2] Two subgenera are recognized. One, A.(Amaltheus) is already described. The other A. (Pseudamaltheus), sometimes expressed as genus, is a late derivative of (Amaltheus) with an early loss of keel and ribbing and an extreme development of strigation. References
1. ^{{cite journal|last=Sepkoski |first=Jack |title=A compendium of fossil marine animal genera (Cephalopoda entry) | journal=Bulletins of American Paleontology |volume=363 |pages=1–560 | year=2002 | url=http://strata.geology.wisc.edu/jack/showgenera.php?taxon=231&rank=class |accessdate=2017-10-18 |deadurl=yes | archiveurl=https://web.archive.org/web/20160225225905/http://strata.geology.wisc.edu/jack/showgenera.php?taxon=231&rank=class | archivedate=2016-02-25 |df= }} 2. ^{{cite web | title= Paleobiology Database - Amaltheus |authorlink =| coauthors = | year = | url = http://paleodb.org/cgi-bin/bridge.pl?action=checkTaxonInfo&taxon_no=14539&is_real_user=1| accessdate = 2017-10-19 }}
5 : Ammonitida genera|Eoderoceratoidea|Jurassic ammonites|Early Jurassic ammonites of Europe|Fossil taxa described in 1808 |
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