ABSTRACT
This chapter reviews the basics of facies analysis and propose expectations on hypotheses of paleoecology, particularly in reference to paleoenvironmental interpretations. The fossiliferous horizon, containing mollusks, fishes, snakes, and large calcareous concretions, is in a black shale layer within the La Luna Formation, 28 meters above the base of the La Aguada Member. Flipperlike appendages in mosasaurian lizards strongly suggest they would, by analogy, have functioned like the flippers of modern whales—as steering and sometimes propulsive structures for an animal living in water. The unit is referred to the Alcobaca Formation, which is considered a lateral equivalent to Kimmeridgian-aged Abadia Formation. The age of the rocks at Selisca–Bilek, Bosnia-Herzegovina, has been debated for some time, ranging from the “Neocomian” to Cenomanian–Turonian, but the consensus seems to be that they are Upper Cenomanian in age. Menarana nosymena is known only from the Upper Cretaceous Maevarano Formation, an outcropping near Berivotra in the Mahajanga Basin of north-western Madagascar.
