Acanthocerataceae
Encyclopedia
Acanthocerataceae is a superfamily of extinct Upper Creataceous ammonoid cephalopods belonging to the order, Ammonitida
, and comprising some 10 or so families.
in the revised version of Part L of the Treatise, the Binneyitidae is replaced by the Forbesiceratidae with the Binneyitidae now in the Hoplitaceae and the Forbesiceratidae included in the Acanthocerataceae. The Leymeriellidae, based on the Lower Albian genus, Leymeriella, was added, extending the range downward. The name Tissotiidae was replaced by Pseudotissotiidae. The Libycoceratidae, proposed by Zaborski, 1982, for the Upper Campainian - Maastrictian Libycoceras, was split of from the Sphenodiscidae. Other families remain essentially the same, except for the addition of newer genera.
The replacement of the Tissotiidae by the Pseudotissotiidae in the revised classification of the Acanthoceraticeae in the Treatise (1996) is based on the earlier appearance of the subfamily Psudotissotiinae in the Lower Turonian, followed by the Tissotiinae in the Upper Turonian. Other newer classifications e.g. split the Tissotiidae into two families, the earlier Pseudotissotiidae and the later, revised but smaller, Tissotiidae. Fatmi and Kennedy, 1999, returned Libycoceras, sole genus of the Libycoceratidae, to its original position in the Sphenodicidae, so negating the Libycoceratidae.
Ammonitida
The Ammonitida is an order of more highly evolved ammonoid cephalopods from the Jurassic and Cretaceous time periods, commonly with intricate ammonitic sutures....
, and comprising some 10 or so families.
Analysis
Members of the Acanthocerataceae are typically strongly ribbed and have a tendency to develop proninent tubercles, although other types including those with oxyconic shells are included.Fundamental
Families included in the Treatise, Part L,1957 are:- AcanthoceratidaeAcanthoceratidaeAcanthoceratidae is an extinct family of cephalopods belonging to the Ammonite subclass. The Type genus is Acanthoceras.-Referenceas:*http://paleodb.org/cgi-bin/bridge.pl?action=checkTaxonInfo&taxon_no=95294&is_real_user=1...
- Binneyitidae
- Brancoceratidae
- Coilopoceratidae
- CollignoniceratidaeCollignoniceratidaeCollignoniceratidae is a family of Upper Cretaceous ammonites characterized by typically more or less evolute shells with compressed, oval, or square whorl sections; serrate or entire keels; and dense ribs with one to 5 tubercles....
- Flickiidae
- Lyelliceratidae
- Sphenodiscidae
- TissotiidaeTissotiidaeTissotiidae is a family of ammonites belonging to the Acanthocerataceae. Members of the Tissotiidae tend to have smooth, strongly involute shells with deeply impressed inner rims to the whorls where subsequent whorls wrap around those prior. Shells may be narrow and discoidal, broad and...
- VascoceratidaeVascoceratidaeThe Vascocertidae, named by Spath is family of Upper Cretaceous ammonites in the Superfamily Acanthocerataceae characterized by shells that are either smooth or bluntly tuberculate, or have sparse, coarse ribs. Sutural elements are shallow, irregular, and slightly indented, or deep and very indented...
New perspectives
According to Wright Calloman, and Howarth. 1996,in the revised version of Part L of the Treatise, the Binneyitidae is replaced by the Forbesiceratidae with the Binneyitidae now in the Hoplitaceae and the Forbesiceratidae included in the Acanthocerataceae. The Leymeriellidae, based on the Lower Albian genus, Leymeriella, was added, extending the range downward. The name Tissotiidae was replaced by Pseudotissotiidae. The Libycoceratidae, proposed by Zaborski, 1982, for the Upper Campainian - Maastrictian Libycoceras, was split of from the Sphenodiscidae. Other families remain essentially the same, except for the addition of newer genera.
The replacement of the Tissotiidae by the Pseudotissotiidae in the revised classification of the Acanthoceraticeae in the Treatise (1996) is based on the earlier appearance of the subfamily Psudotissotiinae in the Lower Turonian, followed by the Tissotiinae in the Upper Turonian. Other newer classifications e.g. split the Tissotiidae into two families, the earlier Pseudotissotiidae and the later, revised but smaller, Tissotiidae. Fatmi and Kennedy, 1999, returned Libycoceras, sole genus of the Libycoceratidae, to its original position in the Sphenodicidae, so negating the Libycoceratidae.