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tokens: their rotation profiles did not commence until later. A sample of ETGs were observed to be elongated (Sandage, Freeman Stokes 1970 ), which was expected to be due to rotation (Larson 1975 ). Early measurements of rotation profiles in lenticular (S0) galaxies confirmed the expectation of strong rotation (Williams 1975 ). Astronomers were then surprised by data suggesting that there was little rotation in some elliptical (E) galaxies (e.g. Bertola Capaccioli 1975 , who measured significantly less rotation in the flattened elliptical NGC 4697 than present in spiral galaxies). This unexpected finding led to much research regarding the nature of rotation versus anisotropic velocity dispersion (e.g. Illingworth 1977 ; Binney 1978 ; Schechter Gunn 1979 ; Davies 1981 ; Kormendy Illingworth 1982 ; Davies et al. 1983 ). One of the early manners in which information about rotational support was condensed was the so-called Binney ( 1978 ) diagram. This diagram presented the ratio of the maximum rotational velocity to the central velocity dispersion v /σ against the ellipticity ε for individual galaxies. In particular, this diagram was used by Binney ( 1978 ) to address the question of how galaxies that are not rotationally supported can be elongated by anisotropy. Davies et al. ( 1983 ) later used this diagram and noted that fainter ellipticals ( M B > −20.5 mag) tended to be rotationally supported, whereas brighter ellipticals ( M B −20.5 mag) were pressure supported by near-isotropic velocity dispersion. The use of this diagram was ideal for longslit data, in which a maximum rotation value along the major axis and a central velocity dispersion could be measured. With the increasing use of two-dimensional spectroscopy, in particular via integral field units (IFUs), much more information was available with which to characterize the kinematics of galaxies. In order to utilize 2D measurements of both velocity and velocity dispersion within a specified aperture, an observationally measureable, luminosity-weighted spin parameter, denoted by λ R , was developed by the SAURON team (Emsellem et al. 2007 ). The use of spatial weighting allowed this parameter to better indicate the rotation of galaxies with non-conventional kinematics (whose properties could not simply be summarized by major-axis measurements, such as galaxies with kinematic twists and misalignments as was later discussed by Krajnović et al. 2011 ). The main outcome of the use of the λ R parameter by the SAURON (de Zeeuw et al. 2002 ) and ATLAS 3D (Cappellari et al. 2011a ) teams was to plot this parameter in conjunction with the ellipticity ε in a spin-ellipticity diagram to identify two classes of early-type galaxies according to their kinematics: fast and slow central rotators. Despite the use of high-quality 2D kinematic data, the final results are still typically reduced to a single measurement for each galaxy. The breadth of information which can be gained from this diagram is further