1) Middle Jurassic extinction
Found on
https://www.crosswordclues.com/clue/megalytoceras
Megalytoceras is an extinct ammonite cephalopod from the middle Jurassic, belonging to the suborder Lytoceratina. The shell of Megalytoceras is evolute and grew 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,...
Found on
http://en.wikipedia.org/wiki/Megalytoceras
No exact match found.
