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Mohorovičić discontinuity

The Mohorovičić discontinuity, usually referred to as the Moho, is the boundary between the Earth's crust and the mantle. The Moho serves to separate both oceanic crust and continental crust from underlying mantle. The Mohorovičić discontinuity was first identified in 1909 by Andrija Mohorovičić, a Croatian seismologist, when he observed the abrupt increase in the velocity of earthquake waves (specifically P-waves) at this point.

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Morphospecies Concept

Species are defined on the basis of consistent morphological differences. See also biological species concept and phylogenetic species concept.

Mould

An imprint of a fossil. See also cast.