Mammites
Encyclopedia
Mammites is an Upper Cretaceous ammonite
belonging to the acanthoceratacean family, Acanthoceratidae
, and is the type genus for the subfamily Mammitinae. It was named by Laube and Bruder in 1887. It range is Lower to Upper Turonian
.
Mammites is typically stout, usually with a rectangular or squarish whorl section and flattish to slightly concave venter. Ornamentation is dominated by strong umbilical tubercles and moderate inner and outer ventrolateral tubercles. Ribs are somewhat prominent in juveniles stages but tend to become inconspicuous in the adult. The suture is ammonitic but rather simple. Some species, those with broad first lateral lobes in the suture, have been reassigned to Morrowites
.
Mammites and Morrowites are rather similar except that Mammites as redefined has a narrow first later lobe while that in Morrowites is broad and the early whorls in Morrowites are smooth except for widely spaced ribs and constrictions while those in Mammites have normal ribs and tubercles.
Ammonitina
The Ammonitina comprises a diverse suborder of ammonoid cephalopods that lived during the Jurassic and Cretaceous periods of the Mesozoic Era. They are excellent index fossils, and it is often possible to link the rock layer in which they are found to specific geological time periods.The shells of...
belonging to the acanthoceratacean family, Acanthoceratidae
Acanthoceratidae
Acanthoceratidae 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...
, and is the type genus for the subfamily Mammitinae. It was named by Laube and Bruder in 1887. It range is Lower to Upper Turonian
Turonian
The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous epoch, or a stage in the Upper Cretaceous series. It spans the time between 93.5 ± 0.8 Ma and 89.3 ± 1 Ma...
.
Mammites is typically stout, usually with a rectangular or squarish whorl section and flattish to slightly concave venter. Ornamentation is dominated by strong umbilical tubercles and moderate inner and outer ventrolateral tubercles. Ribs are somewhat prominent in juveniles stages but tend to become inconspicuous in the adult. The suture is ammonitic but rather simple. Some species, those with broad first lateral lobes in the suture, have been reassigned to Morrowites
Morrowites
Morrowites, named by Cobban and Hook, 1983, is described in Memoir 41 NMBM&MR as a moderate to large-sized ammonite with quadrangular to depressed whorls, broadly rounded to depressed venter, low ribs, umbilical and inner and outer ventrolateral tubercles and smooth early whorls except for...
.
Mammites and Morrowites are rather similar except that Mammites as redefined has a narrow first later lobe while that in Morrowites is broad and the early whorls in Morrowites are smooth except for widely spaced ribs and constrictions while those in Mammites have normal ribs and tubercles.