''Megalytoceras'' is an extinct genus of

ammonite Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...

from the middle Jurassic, belonging to the suborder

Lytoceratina Lytoceratina is a Suborder (biology), suborder of Jurassic and Cretaceous Ammonitida, ammonites that produced loosely coiled, evolute and gyroconic shells in which the sutural element are said to have complex moss-like endings. Morphologic chara ...

. The shell of ''Megalytoceras'' is evolute and grew to be fairly large, to as much as 24.5 cm. (8 3/4 in.) in diameter in ''M. amplum'', from the Aalenian of France. Early whorls are elliptical in section and bear periodic flares. Later, or outer, whorls are smooth with convergent sides. The outer rim, or venter, is rounded. Embracement of previous whorls by the next is slight to mild. The umbilicus is rather wide, with an abrupt edge. ''Megalytoceras'' and its close relative '' Metrolytoceras'' are included in the Megalytoceratinae

Distribution

Only found at Cerro Mendez, Opalinum Zone, Andalucia (Jurassic of Spain)

External links

''Megalytoceras'' BUCKMAN, 1905
(in French)

(in French)

References

;Notes ;Bibliography * Jurassic ammonites Toarcian first appearances Middle Jurassic extinctions Ammonitida genera Lytoceratidae {{ammonite-stub