genus iguanodon: type genus of the Iguanodontidae
entity: that which is perceived or known or inferred to have its own distinct existence (living or nonliving)
planck's law: (physics) the basis of quantum theory; the energy of electromagnetic waves is contained in indivisible quanta that have to be radiated or absorbed as a whole; the magnitude is proportional to frequency where the constant of proportionality is given by Planck's constant