It is probably the l<span>amellae.
The lamellae are sheets of bony matrix. This bony matrix is produced by o</span>steoblasts, which are cells that synthesise collagen<span> and specialised proteins like </span>osteocalcin<span> and </span>osteopontin. These are then the most important constituents of the bony matrix.
C Fossils allow scientists to have an idea of the time scale that traits evolved.
The seven SI units are: kilogram, meter, second, kelvin,mole, ampere and candela.
Out of these seven, the one that will probably be part of the definition of a lumen is candela.
The luminous intensity of a light source is the the luminous flux emitted by that light source in a unit solid angle. The SI unit of luminous flux is lumen and the SI unit of luminous intensity is lumen divided by steradian [lumen/steradian] which is called Candela.<span />